Chapter 60

Boat voyage to Silhet—River—Palms—Teelas—Botany—Fish weirs—Forests of Cachar—Sandal-wood, etc.—Porpoises—Alligators—Silchar—Tigers—Rice crops—Cookies—Munniporees—Hockey—Varnish—Dance—Nagas—Excursion to Munnipore frontier—Elephant bogged—Bamboos—_Cardiopteris_—Climate, etc., of Cachar—Mosquitos—Fall of banks—Silhet—Oaks—_Stylidium_—Tree-ferns—Chattuc—Megna—Meteorology— Palms—Noacolly—Salt-smuggling—Delta of Ganges and Megna—Westward progress of Megna—Peat—Tide—Waves—Earthquakes—Dangerous navigation—Moonlight scenes—Mud island—Chittagong—Mug tribes—Views—Trees—Churs—Flagstaff hill—Coffee—Pepper—Tea, etc.—Excursions from Chittagong—_Dipterocarpi_ or Gurjun oil trees—Earthquake—Birds—Papaw—Bleeding of stems—Poppy and Sun fields—Seetakoond—Bungalow and hill—Perpetual flame—_Falconeria—Cycas_—Climate—Leave for Calcutta—Hattiah island—Plants—Sunderbunds—Steamer—Tides—_Nipa fruticans_—Fishing—Otters—Crocodiles—_Phœnix paludosa_—Departure from India.

We left Churra on the 17th of November, and taking boats at Pundua, crossed the Jheels to the Soormah, which we ascended to Silhet. Thence we continued our voyage 120 miles up the river in canoes, to Silchar, the capital of the district of Cachar: the boats were such as I described at Chattuc, and though it was impossible to sit upright in them, they were paddled with great swiftness. The river at Silhet is 200 yards broad; it is muddy, and flows with a gentle current of two to three miles an hour, between banks six to twelve feet high. As we glided up its stream, villages became rarer, and eminences more frequent in the Jheels. The people are a tall, bold, athletic Mahometan race, who live much on the water, and cultivate rice, sesamum, and radishes, with betel-pepper in thatched enclosures as in Sikkim: maize and sugar are rarer, bamboos abound, and four palms (_Borassus, Areca,_ cocoa-nut, and _Caryota_) are planted, but there are no date-palms.

The Teelas (or hillocks) are the haunts of wild boars, tigers, and elephants, but not of the rhinoceros; they are 80 to 200 feet high, of horizontally stratified gravel and sand, slates, and clay conglomerates, with a slag-like honey-combed sandstone; they are covered with oaks, figs, _Heretiera,_ and bamboos, and besides a multitude of common Bengal plants, there are some which, though generally considered mountain or cold country genera, here descend to the level of the sea; such are _Kadsura, Rubus, Camellia,_ and _Sabia_; _Aerides_ and _Saccolabia_ are the common orchids, and rattan-canes and _Pandani_ render the jungles impenetrable.

A very long sedge (_Scleria_) grows by the water, and is used for thatching: boatloads of it are collected for the Calcutta market, for which also were destined many immense rafts of bamboo, 100 feet long. The people fish much, using square and triangular drop-nets stretched upon bamboos, and rude basket-work weirs, that retain the fish as the river falls. Near the villages we saw fragments of pottery three feet below the surface of the ground, shewing that the bank, which is higher than the surrounding country, increases from the annual overflow.

About seventy miles up the river, the mountains on the north, which are east of Jyntea, rise 4000 feet high in forest-clad ranges like those of Sikkim. Swamps extend from the river to their base, and penetrate their valleys, which are extremely malarious: these forests are frequented by timber-cutters, who fell jarool (_Lagerstrœmia Reginæ_), a magnificent tree with red wood, which, though soft, is durable under water, and therefore in universal use for boat-building. The toon is also cut, with red sandal-wood (_Adenanthera pavonina_); also Nageesa,[373] _Mesua ferrea,_ which is highly valued for its weight, strength, and durability: _Aquilaria agallocha,_ the eagle-wood, a tree yielding uggur oil, is also much sought for its fragrant wood, which is carried to Silhet and Azmerigunj, where it is broken up and distilled. Neither teak, sissoo, sal, nor other _Dipterocarpi,_ are found in these forests.

[373] There is much dispute amongst oriental scholars about the word Nageesa; the Bombay philologists refer it to a species of _Garcinia,_ whilst the pundits on the Calcutta side of India consider it to be _Mesua ferrea._ Throughout our travels in India, we were struck with the undue reliance placed on native names of plants, and information of all kinds; and the pertinacity with which each linguist adhered to his own crotchet as to the application of terms to natural objects, and their pronunciation. It is a very prevalent, but erroneous, impression, that savage and half-civilised people have an accurate knowledge of objects of natural history, and a uniform nomenclature for them.

Porpoises, and both the long and the short-nosed alligator, ascend the Soormah for 120 miles, being found beyond Silchar, which place we reached on the 22nd, and were most hospitably received by Colonel Lister, the political agent commanding the Silhet Light Infantry, who was inspecting the Cookie levy, a corps of hill-natives which had lately been enrolled.

The station is a small one, and stands about forty feet above the river, which however rises half that height in the rains. Long low spurs of tertiary rocks stretch from the Tipperah hills for many miles north, through the swampy Jheels to the river; and there are also hills on the opposite or north side, but detached from the Cookie hills, as the lofty blue range twelve miles north of the Soormah is called. All these mountains swarm with tigers, wild buffalos, and boars, which also infest the long grass of the Jheels.

The elevation of the house we occupied at Silchar was 116 feet above the sea. The bank it stood on was of clay, with soft rocks of conglomerate, which often assume the appearance of a brown sandy slag.

During the first Birmese war, Colonel Lister was sent with a force up to this remote corner of Bengal, when the country was an uninhabited jungle, so full of tigers that not a day passed without one or more of his grass or wood-cutters being carried off. Now, thousands of acres are cultivated with rice, and during our stay we did not see a tiger. The quantity of land brought into cultivation in this part of Bengal, and indeed throughout the Gangetic delta, has probably been doubled during the last twenty years, and speaks volumes for the state of the peasant under the Indian Company’s sway, as compared with his former condition. The Silchar rice is of admirable quality, and much is imported to Silhet, the Jheels not producing grain enough for the consumption of the people. Though Silchar grows enough for ten times its population, there was actually a famine six weeks before our arrival, the demand from Silhet being so great.

The villages of Cachar are peopled by Mahometans, Munniporees, Nagas, and Cookies; the Cacharies themselves being a poor and peaceful jungle tribe, confined to the mountains north of the Soormah. The Munniporees[374] are emigrants from the kingdom of that name, which lies beyond the British possessions, and borders on Assam and Birmah. Low ranges of forest-clad mountains at the head of the Soormah, separate it from Silchar, with which it is coterminous; the two chief towns being seven marches apart. To the south-east of Silchar are interminable jungles, peopled by the Cookies, a wild Indo-Chinese tribe, who live in a state of constant warfare, and possess the whole hill-country from this, southward to beyond Chittagong. Two years ago they invaded and ravaged Cachar, carrying many of the inhabitants into slavery, and so frightening the people, that land previously worth six rupees a biggah, is now reduced to one and a half. Colonel Lister was sent with a strong party to rescue the captives, and marched for many days through their country without disturbing man or beast; penetrating deep forests of gigantic trees and tall bamboos, never seeing the sun above, or aught to the right and left, save an occasional clearance and a deserted village. The incursion, however, had its effects, and the better inclined near the frontier have since come forward, and been enrolled as the Cookie levy.

[374] The Munnipore valley has never been explored by any naturalist, its mountains are said to be pine-clad, and to rise 8000 feet above the level of the sea. The Rajah is much harassed by the Birmese, and is a dependant of the British, who are in the very frequent dilemma of supporting on the throne a sovereign opposed by a strong faction of his countrymen, and who has very dubious claims to his position. During our stay at Silchar, the supposed rightful Rajah was prevailing over the usurper; a battle had been fought on the hills on the frontier, and two bodies floated past our bungalow, pierced with arrows.

The Munnipore emigrants are industrious settlers for a time, but never remain long in one place: their religion is Hindoo, and they keep up a considerable trade with their own country, whence they import a large breed of buffalos, ponies, silks, and cotton cloths dyed with arnotto (_Bixa_), and universally used for turbans. They use bamboo blowing-tubes and arrows for shooting birds, make excellent shields of rhinoceros hide (imported from Assam), and play at hockey on horseback like the Western Tibetans. A fine black varnish from the fruit of _Holigarna longifolia,_ is imported from Munnipore, as is another made from _Sesuvium Anacardium_ (marking-nut), and a remarkable black pigment resembling that from _Melanorhœa usitatissima,_ which is white when fresh, and requires to be kept under water.[375]

[375] This turns of a beautiful black colour when applied to a surface, owing, according to Sir D. Brewster, to the fresh varnish consisting of a congeries of minute organised particles, which disperse the rays of light in all directions; the organic structure is destroyed when the varnish dries and the rays of light are consequently transmitted.

One fine moonlight night we went to see a Munnipore dance. A large circular area was thatched with plantain leaves, growing on their trunks, which were stuck in the ground; and round the enclosure was a border neatly cut from the white leaf-sheaths of the same tree. A double enclosure of bamboo, similarly ornamented, left an inner circle for the performers, and an outer for the spectators: the whole was lighted with oil lamps and Chinese paper lanterns. The musicians sat on one side, with cymbals, tomtoms, and flutes, and sang choruses.

The performances began by a copper-coloured Cupid entering and calling the virgins with a flute; these appeared from a green-room, to the number of thirty or forty, of all ages and sizes. Each had her hair dressed in a topknot, and her head covered with a veil; a scarlet petticoat loaded with tinsel concealed her naked feet, and over this was a short red kirtle, and an enormous white shawl was swathed round the body from the armpits to the waist. A broad belt passed over the right shoulder and under the left arm, to which hung gold and silver chains, corals, etc., with tinsel and small mirrors sewed on everywhere: the arms and hands were bare, and decorated with bangles and rings.

Many of the women were extremely tall, great stature being common amongst the Munniporees. They commenced with a prostration to Cupid, around whom they danced very slowly, with the arms stretched out, and the hands in motion; at each step the free foot was swung backwards and forwards. Cupid then chose a partner, and standing in the middle went through the same motions, a compliment the women acknowledged by curtseying and whirling round, making a sort of cheese with their petticoats, which, however, were too heavy to inflate properly.

The Nagas are another people found on this frontier, chiefly on the hills to the north: they are a wild, copper-coloured, uncouth jungle tribe, who have proved troublesome on the Assam frontier. Their features are more Tartar than those of the Munniporees, especially amongst the old men. They bury their dead under the threshold of their cottages. The men are all but naked, and stick plumes of hornbills’ feathers in their hair, which is bound with strips of bamboo: tufts of small feathers are passed through their ears, and worn as shoulder lappets. A short blue cotton cloth, with a fringe of tinsel and tufts of goat’s hair dyed red, is passed over the loins in front only: they also wear brass armlets, and necklaces of cowries, coral, amber, ivory, and boar’s teeth. The women draw a fringed blue cloth tightly across the breast, and wear a checked or striped petticoat. They are less ornamented than the men, and are pleasing looking; their hair is straight, and cut short over the eyebrows.

The Naga dances are very different from those of the Munniporees; being quick, and performed in excellent time to harmonious music. The figures are regular, like quadrilles and country-dances: the men hold their knives erect during the performance, the women extend their arms only when turning partners, and then their hands are not given, but the palms are held opposite. The step is a sort of polka and balancez, very graceful and lively. A bar of music is always played first, and at the end the spectators applaud with two short shouts. Their ear for music, and the nature of their dance, are as Tibetan as their countenances, and different from those of the Indo-Chinese tribes of the frontier.

We had the pleasure of meeting Lieutenant Raban at Silchar, and of making several excursions in the neighbourhood with him; for which Colonel Lister here, as at Churra, afforded us every facility of elephants and men. Had we had time, it was our intention to have visited Munnipore, but we were anxious to proceed to Chittagong. I however made a three days’ excursion to the frontier, about thirty miles distant, proceeding along the north bank of the Soormah. On the way my elephant got bogged in crossing a deep muddy stream: this is sometimes an alarming position, as should the animal become terrified, he will seize his rider, or pad, or any other object (except his driver), to place under his knees to prevent his sinking. In this instance the driver in great alarm ordered me off, and I had to flounder out through the black mud. The elephant remained fast all night, and was released next morning by men with ropes.

The country continued a grassy level, with marshes and rice cultivation, to the first range of hills, beyond which the river is unnavigable; there also a forest commences, of oaks, figs, and the common trees of east Bengal. The road hence was a good one, cut by Sepoys across the dividing ranges, the first of which is not 500 feet high. On the ascent bamboos abound, of the kind called Tuldah or Dulloah, which has long very thin-walled joints; it attains no great size, but is remarkably gregarious. On the east side of the range, the road runs through soft shales and beds of clay, and conglomerates, descending to a broad valley covered with gigantic scattered timber-trees of jarool, acacia, _Diospyros, Urticeæ,_ and _Bauhiniæ,_ rearing their enormous trunks above the bamboo jungle: immense rattan-canes wound through the forest, and in the gullies were groves of two kinds of tree-fern, two of _Areca, Wallichia_ palm, screw-pine, and _Dracæna._ Wild rice grew abundantly in the marshes, with tall grasses; and _Cardiopteris_[376] covered the trees for upwards of sixty feet, like hops, with a mass of pale-green foliage, and dry white glistening seed-vessels. This forest differed from those of the Silhet and Khasia mountains, especially in the abundance of bamboo jungle, which is, I believe, the prevalent feature of the low hills in Birmah, Ava, and Munnipore; also in the gigantic size of the rattans, 1arger palms, and different forest trees, and in the scanty undergrowth of herbs and bushes. I only saw, however, the skirts of the forest; the mountains further east, which I am told rise several thousand feet in limestone cliffs, are doubtless richer in herbaceous plants.

[376] A remarkable plant of unknown affinity; see Brown and Bennett, “Flora Java:” it is found in the Assam valley and Chittagong.

The climate of Cachar partakes of that of the Jheels in its damp equable character: during our stay the weather was fine, and dense fogs formed in the morning: the mean maximum was 80°, minimum 58·4°.[377]

[377] The temperature does not rise above 90° in summer, nor sink below 45° or 50° in January: forty-seven comparative observations with Calcutta showed the mean temperature to be 1·8° lower at Silchar, and the air damper, the saturation point being, at Calcutta 0·3791, at Silchar 0·4379.

The annual rain-fall in 1850 was 111·60 inches, according to a register kindly given me by Captain Verner. There are few mosquitos, which is one of the most curious facts in the geographical distribution of these capricious bloodsuckers; for the locality is surrounded by swamps, and they swarm at Silhet, and on the river lower down. Both on the passage up and down, we were tormented in our canoes by them for eighty or ninety miles above Silhet, and thence onwards to Cachar we were free.

On the 30th of November, we were preparing for our return to Silhet, and our canoes were loading, when we were surprised by a loud rushing noise, and saw a high wave coming down the river, swamping every boat that remained on its banks, whilst most of those that pushed out into the stream, escaped with a violent rocking. It was caused by a slip of the bank three quarters of a mile up the stream, of no great size, but which propagated a high wave. This appeared to move on at about the rate of a mile in three or four minutes, giving plenty of time for our boatmen to push out from the land on hearing the shouts of those first overtaken by the calamity; but they were too timid, and consequently one of our canoes, full of papers, instruments, and clothes, was swamped. Happily our dried collections were not embarked, and the hot sun repaired much of the damage.

We left in the evening of the 2nd of December, and proceeded to Silhet, where we were kindly received by Mr. Stainforth, the district judge. Silhet, the capital of the district of the same name, is a large Mahometan town, occupying a slightly raised part of the Jheels, where many of the Teelas seem joined together by beds of gravel and sand. In the rains it, is surrounded by water, and all communication with other parts is by boats: in winter, Jynteapore and Pundua may be reached by land, crossing creeks innumerable on the way. Mr. Stainforth’s house, like those of most of the other Europeans, occupies the top of one of the Teelas, 150 feet high, and is surrounded by fine spreading oaks,[378] _Garcinia,_ and _Diospyros_ trees. The rock of which the hill is composed, is a slag-like ochreous sandstone, covered in most places with a shrubbery of rose-flowered _Melastoma,_ and some peculiar plants.[379]

[378] It is not generally known that oaks are often very tropical plants; not only abounding at low elevations in the mountains, but descending in abundance to the level of the sea. Though unknown in Ceylon, the Peninsula of India, tropical Africa, or South America, they abound in the hot valleys of the Eastern Himalaya, East Bengal, Malay Peninsula, and Indian islands; where perhaps more species grow than in any other part of the world. Such facts as this disturb our preconceived notions of the geographical distribution of the most familiar tribes of plants, and throw great doubt on the conclusions which fossil plants are supposed to indicate.

[379] _Gelonium, Adelia, Moacurra, Linostoma, Justicia, Trophis, Connarus, Ixora, Congea, Dalhousiea, Grewia, Myrsine, Buttneria_; and on the shady exposures a _Calamus, Briedelia,_ and various ferns.

Broad flat valleys divide the hills, and are beautifully clothed with a bright green jungle of small palms, and many kinds of ferns. In sandy places, blue-flowered _Burmannia, Hypoxis,_ and other pretty tropical annuals, expand their blossoms, with an inconspicuous _Stylidium,_ a plant belonging to a small natural family, whose limits are so confined to New Holland, that this is almost the only kind that does not grow in that continent. Where the ground is swampy, dwarf _Pandanus_ abounds, with the gigantic nettle, _Urtica crenulata_ (“Mealum-ma” of Sikkim, see p. 189).

The most interesting botanical ramble about Silhet is to the tree-fern groves on the path to Jynteapore, following the bottoms of shallow valleys between the Teelas, and along clear streams, up whose beds we waded for some miles, under an arching canopy of tropical shrubs, trees, and climbers, tall grasses, screw-pines, and _Aroideæ._ In the narrower parts of the valleys the tree-ferns are numerous on the slopes, rearing their slender brown trunks forty feet high, with feathery crowns of foliage, through which the sun-beams trembled on the broad shining foliage of the tropical herbage below.

Silhet, though hot and damp, is remarkably healthy, and does not differ materially in temperature from Silchar, though it is more equable and humid.[380] It derives some interest from having been first brought into notice by the enterprise of one of the Lindsays of Balcarres, at a time when the pioneers of commerce in India encountered great hardships and much personal danger. Mr. Lindsay, a writer in the service of the East India Company, established a factory at Silhet, and commenced the lime trade with Calcutta,[381] reaping an enormous fortune himself, and laying the foundation of that prosperity amongst the people which has been much advanced by the exertions of the Inglis family, and has steadily progressed under the protecting rule of the Indian government.

[380] During our stay of five days the mean maximum temperature was 74°, minimum 64·8°: that of thirty-two observations compared with Calcutta show that Silhet is only 1·7° cooler, though Mr. Stainforth’s house is upwards of 2° further north, and 160 feet more elevated. A thermometer sunk two feet seven inches, stood at 73·5°. The relative saturation-points were, Calcutta ·633, Silhet ·821.

[381] For an account of the early settlement of Silhet, see “Lives of the Lindsays,” by Lord Lindsay.

From Silhet we took large boats to navigate the Burrampooter and Megna, to their embouchure in the Bay of Bengal at Noacolly, a distance of 250 miles, whence we were to proceed across the head of the bay to Chittagong, about 100 miles farther. We left on the 7th of December, and arrived at Chattuc on the 9th, where we met our Khasia collectors with large loads of plants, and paid them off. The river was now low, and presented a busy scene, from the numerous trading boats being confined to its fewer and deeper channels. Long grasses and sedges (_Arundo, Saccharum_ and _Scleria_), were cut, and stacked along the water’s edge, in huge brown piles, for export and thatching.

On the 13th December, we entered the broad stream of the Megna. Rice is cultivated along the mud flats left by the annual floods, and the banks are lower and less defined than in the Soormah, and support no long grasses or bushes. Enormous islets of living water-grasses (_Oplismenus stagninus_) and other plants, floated past, and birds became more numerous, especially martins and egrets. The sun was hot, but the weather otherwise cool and pleasant: the mean temperature was nearly that of Calcutta, 69·7°, but the atmosphere was more humid.[382]

[382] The river-water was greenish, and a little cooler (73·8°) than that of the Soormah (74·3°), which was brown and muddy. The barometer on the Soormah stood 0·028 inch higher than that of Calcutta (on the mean of thirty-eight observations), whereas on the Megna the pressure was 0·010 higher. As Calcutta is eighteen feet above the level of the Bay of Bengal, this shows that the Megna (which has no perceptible current) is at the level of the sea, and that either the Soormah is upwards of thirty feet above that level, or that the atmospheric pressure there, and at this season, is less than at Calcutta, which, as I have hinted at p. 259, is probably the case.

On the 14th we passed the Dacca river; below which the Megna is several miles wide, and there is an appearance of tide, from masses of purple _Salvinia_ (a floating plant, allied to ferns), being thrown up on the beach like sea-weed. Still lower down, the vegetation of the Sunderbunds commences; there is a narrow beach, and behind it a mud bank several feet high, supporting a luxuriant green jungle of palms (_Borassus_ and _Phœnix_), immense fig-trees, covered with _Calami,_ and tall betel-palms, clothed with the most elegant drapery of _Arostichum scandens,_ a climbing fern with pendulous fronds.

Towards the embouchure, the banks rise ten feet high, the river expands into a muddy sea, and a long swell rolls in, to the disquiet of our fresh-water boatmen. Low islands of sand and mud stretch along the horizon: which, together with the ships, distorted by extraordinary refraction, flicker as if seen through smoke. Mud is the all prevalent feature; and though the water is not salt, we do not observe in these broad deltas that amount of animal life (birds, fish, alligators, and porpoises), that teems in the narrow creeks of the western Sunderbunds.

We landed in a canal-like creek at Tuktacolly,[383] on the 17th, and walked to Noacolly, over a flat of hard mud or dried silt, covered with turf of _Cynodon Dactylon._ We were hospitably received by Dr. Baker, a gentleman who has resided here for twenty-three years; and who communicated to us much interesting information respecting the features of the Gangetic delta.

[383] “Colly” signifies a muddy creek, such as intersect the delta.

Noacolly is a station for collecting the revenue and preventing the manufacture of salt, which, with opium, are the only monopolies now in the hands of the East India Company. The salt itself is imported from Arracan, Ceylon, and even Europe, and is stored in great wooden buildings here and elsewhere. The ground being impregnated with salt, the illicit manufacture by evaporation is not easily checked; but whereas the average number of cases brought to justice used to be twenty and thirty in a week, they are now reduced to two or three. It is remarkable, that though the soil yields such an abundance of this mineral, the water of the Megna at Noacolly is only brackish, and it is therefore to repeated inundations and surface evaporations that the salt is due. Fresh water is found at a very few feet depth everywhere, but it is not good.

When it is considered how comparatively narrow the sea-board of the delta is, the amount of difference in the physical features of the several parts, will appear most extraordinary. I have stated that the difference between the northern and southern halves of the delta is so great, that, were all depressed and their contents fossilised, the geologist who examined each by itself, would hardly recognise the two parts as belonging to one epoch; and the difference between the east and west halves of the lower delta is equally remarkable.

The total breadth of the delta is 260 miles, from Chittagong to the mouth of the Hoogly, divided longitudinally by the Megna: all to the west of that river presents a luxuriant vegetation, while to the east is a bare muddy expanse, with no trees or shrubs but what are planted On the west coast the tides rise twelve or thirteen feet, on the east, from forty to eighty. On the west, the water is salt enough for mangroves to grow for fifty miles up the Hoogly; on the east, the sea coast is too fresh for that plant for ten miles south of Chittagong. On the west, fifty inches is the Cuttack fall of rain; on the east, 90 to 120 at Noacolly and Chittagong, and 200 at Arracan. The east coast is annually visited by earthquakes, which are rare on the west; and lastly, the majority of the great trees and shrubs carried down from the Cuttack and Orissa forests, and deposited on the west coast of the delta, are not only different in species, but in natural order, from those that the Fenny and Chittagong rivers bring down from the jungles.[384]

[384] The Cuttack forests are composed of teak, Sal, Sissoo, ebony, _Pentaptera, Buchanania,_ and other trees of a dry soil, and that require a dry season alternating with a wet one. These are unknown in the Chittagong forests, which have Jarool (_Lagerstrœmia_) _Mesua, Dipterocarpi,_ nutmegs, oaks of several kinds, and many other trees not known in the Cuttack forests, and all typical of a perennially humid atmosphere.

We were glad to find at Noacolly that our observations on the progression westwards of the Burrampooter (see p. 253) were confirmed by the fact that the Megna also is gradually moving in that direction, leaving much dry land on the Noacolly side, and forming islands opposite that coast; whilst it encroaches on the Sunderbunds, and is cutting away the islands in that direction. This advance of the fresh waters amongst the Sunderbunds is destructive to the vegetation of the latter, which requires salt; and if the Megna continues its slow course westwards, the obliteration of thousands of square miles of a very peculiar flora, and the extinction of many species of plants and animals that exist nowhere else, may ensue. In ordinary cases these plants, etc., would take up their abode on the east coast, as they were driven from the west; but such might not be the case in this delta; for the sweeping tides of the east coast prevent any such vegetation establishing itself there, and the mud which the eastern rivers carry down, becomes a caking dry soil, unsuited to the germination of seeds.

On our arrival at Calcutta in the following February, Dr. Falconer showed us specimens of very modern peat, dug out of the banks of the Hoogly a few feet below the surface of the soil, in which were seeds of the _Euryale ferox_:[385] this plant is not now known to be found nearer than Dacca (sixty miles north-east, see p. 255), and indicates a very different state of the surface at Calcutta at the date of its deposition than that which exists now, and also shows that the estuary was then much fresher.

[385] This peat Dr. Falconer also found to contain bones of birds and fish, seeds of _Cucumis Madraspatana_ and another Cucurbitaceous plant, leaves of _Saccharum Sara_ and _Ficus cordifolia._ Specks of some glistening substance were scattered through the mass, apparently incipient carbonisation of the peat.

The main land of Noacolly is gradually extending seawards, and has advanced four miles within twenty- three years: this seems sufficiently accounted for by the recession of the Megna. The elevation of the surface of the land is caused by the overwhelming tides and south-west hurricanes in May and October: these extend thirty miles north and south of Chittagong, and carry the waters of the Megna and Fenny back over the land, in a series of tremendous waves, that cover islands of many hundred acres, and roll three miles on to the main land. On these occasions, the average earthy deposit of silt, separated by micaceous sand, is an eighth of an inch for every tide; but in October, 1848, these tides covered Sundeep island, deposited six inches on its level surface, and filled ditches several feet deep. These deposits become baked by a tropical sun, and resist to a considerable degree denudation by rain. Whether any further rise is caused by elevation from below is doubtful; there is no direct evidence of it, though slight earthquakes annually occur; and even when they have not been felt, the water of tanks has been seen to oscillate for three-quarters of an hour without intermission, from no discernible cause.[386]

[386] The natives are familiar with this phenomenon, of which Dr. Baker remembers two instances, one in the cold season of 1834–5, the other in that of 1830–1. The earthquakes do not affect any particular month, nor are they accompanied by any meteorological phenomena.

Noacolly is considered a healthy spot, which is not the case with the Sunderbund stations west of the Megna. The climate is uniformly hot, but the thermometer never rises above 90°, nor sinks below 45°; at this temperature hoar-frost will form on straw, and ice on water placed in porous pans, indicating a powerful radiation.[387]

[387] The winds are north-west and north in the cold season (from November to March), drawing round to west in the afternoons. North-west winds and heavy hailstorms are frequent from March to May, when violent gales set in from the southward. The rains commence in June, with easterly and southerly winds, and the temperature from 82° to 84°; May and October are the hottest months. The rains cease in the end of October (on the 8th of November in 1849, and 12th of November in 1850, the latest epoch ever remembered): there is no land or sea breeze along any part of the coast. During our stay we found the mean temperature for twelve observations to be precisely that of Calcutta, but the humidity was more, and the pressure 0·040 lower.

We left Noacolly on the 19th for Chittagong; the state of the tide obliging us to go on board in the night. The distance is only 100 miles, but the passage is considered dangerous at this time (during the spring-tides) and we were therefore provided with a large vessel and an experienced crew. The great object in this navigation is to keep afloat and to make progress towards the top of the tide and during its flood, and to ground during the ebb in creeks where the bore (tidal wave) is not violent; for where the channels are broad and open, the height and force of this wave rolls the largest coasting craft over and swamps them.

Our boatmen pushed out at 3 in the morning, and brought up at 5, in a narrow muddy creek on the island of Sidhee. The waters retired along channels scooped several fathoms deep in black mud, leaving our vessel aground six or seven feet below the top of the bank, and soon afterwards there was no water to be seen; as far as the eye could reach, all was a glistening oozy mud, except the bleak level surfaces of the islands, on which neither shrub nor tree grew. Soon after 2 p.m. a white line was seen on the low black horizon, which was the tide-wave, advancing at the rate of five miles an hour, with a hollow roar; it bore back the mud that was gradually slipping along the gentle slope, and we were afloat an hour after: at night we grounded again, opposite the mouth of the Fenny.

By moonlight the scene was oppressively solemn: on all sides the gurgling waters kept up a peculiar sound that filled the air with sullen murmurs; the moonbeams slept upon the slimy surface of the mud, and made the dismal landscape more ghastly still. Silence followed the ebb, broken occasionally by the wild whistle of a bird like the curlew, of which a few wheeled through the air: till the harsh roar of the bore was heard, to which the sailors seemed to waken by instinct. The waters then closed in on every side, and the far end of the reflected moonbeam was broken into flashing light, that approached and soon danced beside the boat.

We much regretted not being able to obtain any more accurate data than I have given, as to the height of the tide at the mouth of the Fenny; but where the ebb sometimes retires twenty miles from high-water mark, it is obviously impossible to plant any tide-gauge.

On the 21st we were ashore at daylight on the Chittagong coast far north of the station, and were greeted by the sight of hills on the horizon: we were lying fully twenty feet below high-water mark, and the tide was out for several miles to the westward. The bank was covered with flocks of white geese feeding on short grass, upon what appeared to be detached islets on the surface of the mud. These islets, which are often an acre in extent, are composed of stratified mud; they have perpendicular sides several feet high, and convex surfaces, owing to the tide washing away the earth from under their sides; and they were further slipping seawards, along the gently sloping mud-beach. Few or no shells or seaweed were to be seen, nor is it possible to imagine a more lifeless sea than these muddy coasts present.

We were three days and nights on this short voyage, without losing sight of mud or land. I observed the barometer whenever the boat was on the shore, and found the mean of six readings (all reduced to the same level) to be identical with that at Calcutta. These being all taken at elevations lower than that of the Calcutta observatory, show either a diminished atmospheric pressure, or that the mean level of high-water is not the same on the east and west coasts of the Bay of Bengal: this is quite possible, considering the widely different direction of the tides and currents on each, and that the waters may be banked up, as it were, in the narrow channels of the western Sunderbunds. The temperature of the air was the same as at Calcutta, but the atmosphere was damper. The water was always a degree warmer than the air.

We arrived at Chittagong on the 23rd of December, and became the guests of Mr. Sconce, Judge of the district, and of Mr. Lautour; to both of whom we were greatly indebted for their hospitality and generous assistance in every way.

Chittagong is a large town of Mahometans and Mugs, a Birmese tribe who inhabit many parts of the Malay peninsula, and the coast to the northward of it. The town stands on the north shore of an extensive delta, formed by rivers from the lofty mountains separating this district from Birma. These mountains are fine objects on the horizon, rising 4000 to 8000 feet; they are forest-clad, and inhabited by turbulent races, who are coterminous with the Cookies of the Cachar and Tipperah forests; if indeed they be not the same people. The mountains abound with the splendid timber-trees of the Cachar forests, but like these are said to want teak, Sal, and Sissoo; they have, besides many others,, magnificent Gurjun trees (_Dipterocarpi_), the monarchs of the forests of these coasts.

The natives of Chittagong are excellent shipbuilders and active traders, and export much rice and timber to Madras and Calcutta. The town is large and beautifully situated, interspersed with trees and tanks; the hills resemble those of Silhet, and are covered with a similar vegetation: on these the European houses are built. The climate is very healthy, which is not remarkable, considering how closely it approximates in character to that of Silhet and other places in Eastern Bengal, but very extraordinary, if it be compared with Arracan, only 200 miles further south, which is extremely unhealthy. The prominent difference between the physical features of Chittagong and Arracan, is the presence of mangrove swamps at the latter place, for which the water is too fresh at the former.

The hills about the station are not more than 150 or 200 feet high, and are formed of stratified gravel, sand, and clay, that often becomes nodular, and is interstratified with slag-like iron clay. Fossil wood is found; and some of the old buildings about Chittagong contain nummulitic limestone, probably imported from Silhet or the peninsula of India, with which countries there is no such trade now. The views are beautiful, of the blue mountains forty to fifty miles distant, and the many-armed river, covered with sails, winding amongst groves of cocoa-nuts, Areca palm, and yellow rice fields. Good European houses surmount all the eminences, surrounded by trees of _Acacia_ and _Cæsalpinia._ In the hollows are native huts amidst vegetation of every hue, glossy green _Garciniæ_ and figs, broad plantains, feathery _Cassia_ and Acacias, dark _Mesua_, red-purple _Terminalia,_ leafless scarlet-flowered _Bombax,_ and grey _Casuarina._[388] Seaward the tide leaves immense flats, called churs, which stretch for many miles on either side the offing.

[388] This, which is almost exclusively an Australian genus, is not indigenous at Chittagong: to it belongs an extra-Australian species common in the Malay islands, and found wild as far north as Arracan.

We accompanied Mr. Sconce to a bungalow which he has built at the telegraph station at the south head of the harbour: its situation, on a hill 100 feet above the sea, is exposed, and at this season the sea-breeze was invigorating, and even cold, as it blew through the mat-walls of the bungalow.[389] To the south, undulating dunes stretch along the coast, covered with low bushes, of which a red-flowered _Melastoma_ is the most prevalent,[390] and is considered a species of _Rhododendron_ by many of the residents! The flats along the beach are several miles broad, intersected with tidal creeks, and covered with short grass, while below high-water mark all is mud, coated with green _Conferva._ There are no leafy seaweeds or mangroves, nor any seaside shrub but _Dilivaria ilicifolia._ Animal life is extremely rare; and a _Cardium_-like shell and small crab are found sparingly.

[389] The mean temperature of the two days (29th and 30th) we spent at this bungalow was 66·5°, that of Calcutta being 67·6°; the air was damp, and the barometer 0·144 lower at the flagstaff hill, but it fell and rose with the Calcutta instrument.

[390] _Melastoma,_ jasmine, _Calamus, Ægle Marmelos, Adelia, Memecylon, Ixora, Limostoma, Congea,_ climbing _Cœsalpinia,_ and many other plants; and along their bases large trees of _Amoora, Gaurea,_ figs, _Mesua,_ and _Micromelon._

Coffee has been cultivated at Chittagong with great success; it is said to have been introduced by Sir W. Jones, and Mr. Sconce has a small plantation, from which his table is well supplied. Both Assam and Chinese teas flourish, but Chinamen are wanted to cure the leaves. Black pepper succeeds admirably, as do cinnamon, arrowroot, and ginger.

Early in January we accompanied Mr. Lautour on an excursion to the north, following a valley separated from the coast by a range of wooded hills, 1000 feet high. For several marches the bottom of this valley was broad, flat, and full of villages. At Sidhee, about twenty-five miles from Chittagong, it contracts, and spurs from the hills on either flank project into the middle: they are 200 to 300 feet high, formed of red clay, and covered with brushwood. At Kajee-ke-hath, the most northern point we reached, we were quite amongst these hills, and in an extremely picturesque country, intersected by long winding flat valleys, that join one another: some are full of copsewood, while others present the most beautiful park-like scenery, and a third class expand into grassy marshes or lake-beds, with wooded islets rising out of them. The hillsides are clothed with low jungle, above which tower magnificent Gurjun trees (wood-oil). The whole contour of this country is that of a low bay, whose coast is raised above the sea, and over which a high tide once swept for ages.

The elevation of Hazari-ke-hath is not 100 feet above the level of the sea. It is about ten miles west of the mouth of the Fenny, from which it is separated by hills 1000 feet high; its river falls into that at Chittagong, thirty miles south. Large myrtaceous trees (_Eugenia_) are common, and show a tendency to the Malayan flora, which is further demonstrated by the abundance of Gurjun (_Dipterocarpus turbinatus_). This is the most superb tree we met with in the Indian forests: we saw several species, but this is the only common one here; it is conspicuous for its gigantic size, and for the straightness and graceful form of its tall unbranched pale grey trunk, and small symmetrical crown: many individuals were upwards of 200 feet high, and fifteen in girth. Its leaves are broad, glossy, and beautiful; the flowers (then falling) are not conspicuous; the wood is hard, close-grained, and durable, and a fragrant oil exudes from the trunk, which is extremely valuable as pitch and varnish, etc., besides being a good medicine. The natives procure it by cutting transverse holes in the trunk, pointing downwards, and lighting fires in them, which causes the oil to flow.[391]

[391] The other trees of these dry forests are many oaks, _Henslowia, Gordonia, Engelhardtia, Duabanga, Adelia, Byttneria, Bradleia,_ and large trees of _Pongamia,_ whose seeds yield a useful oil.

On the 8th of January we experienced a sharp earthquake, preceded by a dull thumping sound; it lasted about twenty seconds, and seemed to come up from the southward; the water of a tank by which we were seated was smartly agitated. The same shock was felt at Mymensing and at Dacca, 110 miles north-west of this.[392]

[392] Earthquakes are extremely common, and sometimes violent, at Chittagong, and doubtless belong to the volcanic forces of the Malayan peninsula.

We crossed the dividing ridge of the littoral range on the 9th, and descended to Seetakoond bungalow, on the high road from Chittagong to Comilla. The forests at the foot of the range were very extensive, and swarmed with large red ants that proved very irritating: they build immense pendulous nests of dead and living leaves at the ends of the branches of trees, and mat them with a white web. Tigers, leopards, wild dogs, and boars, are numerous; as are snipes, pheasants, peacocks, and jungle-fowl, the latter waking the morn with their shrill crows; and in strange association with them, common English woodcock, is occasionally found.

The trees are of little value, except the Gurjun, and “Kistooma,” a species of _Bradleia,_ which was stacked extensively, being used for building purposes. The papaw[393] is abundantly cultivated, and its great gourd-like fruit is eaten (called “Papita” or “Chinaman”); the flavour is that of a bad melon, and a white juice exudes from the rind. The _Hodgsonia heteroclita_ (_Trichosanthes_ of Roxburgh), a magnificent Cucurbitaceous climber, grows in these forests; it is the same species as the Sikkim one (see p. 7). The long stem bleeds copiously when cut, and like almost all woody climbers, is full of large vessels; the juice does not, however, exude from these great tubes, which hold air, but from the close woody fibres. A climbing _Apocyneous_ plant grows in these forests, the milk of which flows in a continuous stream, resembling caoutchouc (it is probably the _Urceola elastica,_ which yields Indian-rubber).

[393] The Papaw tree is said to have the curious property of rendering tough meat tender, when hung under its leaves, or touched with the juice; this hastening the process of decay. With this fact, well-known in the West Indies, I never found a person in the East acquainted.

The subject of bleeding is involved in great obscurity, and the systematic examination of the motions in the juices of tropical climbers by resident observers, offers a fertile field to the naturalist. I have often remarked that if a climbing stem, in which the circulation is vigorous, be cut across, it bleeds freely from both ends, and most copiously from the lower, if it be turned downwards; but that if a truncheon be severed, there will be no flow from either of its extremities. This is the case with all the Indian watery-juiced climbers, at whatever season they may be cut. When, however, the circulation in the plant is feeble, neither end of a simple cut will bleed much, but if a truncheon be taken from it, both the extremities will.

The ascent of the hills, which are densely wooded, was along spurs, and over knolls of clay; the rocks were sandy and slaty (dip north-east 60°. The road was good, but always through bamboo jungle, and it wound amongst the low spurs, so that there was no defined crest or top of the pass, which is about 800 feet high. There were no tall palms, tree-ferns, or plantains, no _Hymenophylla_ or _Lycopodia,_ and altogether the forest was smaller and poorer in plants than we had expected. The only palms (except a few rattans) were two kinds of _Wallichia._

From the summit we obtained a very extensive and singular view. At our feet was a broad, low, grassy, alluvial plain, intersected by creeks, bounding a black expanse of mud which (the tide being out) appeared to stretch almost continuously to Sundeep Island, thirty miles distant; while beyond, the blue hills of Tipperah rose on the north-west horizon. The rocks yielded a dry poor soil, on which grew dwarf _Phœnix_ and cycas-palm (_Cycas circinalis_ or _pectinata_).

Descending, we rode several miles along an excellent road, that runs to Tipperah, and stopped at the bungalow of Seetakoond, twenty-five miles north of Chittagong. The west flank of the range which we had crossed is much steeper than the east, often precipitous, and presents the appearance of a sea-worn cliff towards the Bay of Bengal. Near Seetakoond (which is on the plain) a hill on the range, bearing the same name, rises 1,136 feet high, and being damper and more luxuriantly wooded, we were anxious to explore it, and therefore spent some days at the bungalow. Fields of poppy and sun (_Crotalaria juncea_), formed most beautiful crops; the latter grows from four to six feet high, and bears masses of laburnum-like flowers, while the poppy fields resembled a carpet of dark-green velvet, sprinkled with white stars; or, as I have elsewhere remarked, a green lake studded with water-lilies.

The road to the top of Seetakoond leads along a most beautiful valley, and then winds up a cliff that is in many places almost precipitous, the ascent being partly by steps cut in the rock, of which there are 560. The mountain is very sacred, and there is a large Brahmin temple on its flank; and near the base a perpetual flame bursts out of the rock. This we were anxious to examine, and were extremely disappointed to find it a small vertical hole in a slaty rock, with a lateral one below for a draught; and that it is daily supplied by pious pilgrims and Brahmins with such enormous quantities of ghee (liquid butter), that it is to all intents and purposes an artificial lamp; no trace of natural phenomena being discoverable.

On the dry but wooded west face of the mountain, grows _Falconeria,_ a curious Euphorbiaceous tree, with an acrid milky juice that affects the eyes when the wood is cut. Beautiful _Cycas_ palms are also common, with _Terminalia, Bignonia, Sterculia,_ dwarf _Phœnix_ palm, and Gurjun trees. The east slope of the mountain is damper, and much more densely wooded; we there found two wild species of nutmeg trees, whose wood is full of a brown acrid oil, seven palms, tree-ferns, and many other kinds of ferns, several kinds of oak, _Dracæna,_ and figs. The top is 1,136 feet above the sea, and commands an extensive view to all points of the compass; but the forests, in which the ashy bark of the Gurjun trees is conspicuous, and the beautiful valley on the west, are the only attractive features.

The weather on the east side of the range differs at this season remarkably from that on the west, where the vicinity of the sea keeps the atmosphere more humid and warm, and at the same time prevents the formation of the dense fogs that hang over the valleys to the eastward every morning at sunrise. We found the mean temperature at the bungalow, from January 9th till the 13th, to be 70·2°.

We embarked again at Chittagong on the 16th of January, at 10 p.m., for Calcutta, in a very large vessel, rowed by twelve men: we made wretchedly slow progress, for the reasons mentioned above (p. 343), being for four days within sight of Chittagong! On the 20th we only reached Sidhee, and thence made a stretch to Hattiah, an island which may be said to be moving bodily to the westward, the Megna annually cutting many acres from the east side; and the tide-wave depositing mud on the west. The surface is flat, and raised four feet above mean high-water level; the tide rises about 14 feet up the bank, and then retires for miles; the total rise and fall is, however, much less here than in the Fenny, higher up the gulf. The turf is composed of _Cynodon_ and a _Fimbristylis_; and the earth being impregnated with salt, supports different kinds of _Chenopodium._ Two kinds of tamarisk, and a thorny _Cassia_ and _Exœcaria,_ are the only shrubs on the eastern islands; on the central ones a few dwarf mangroves appear, with the holly-leaved _Dilivaria,_ dwarf screw-pine (_Pandanus_), a shrub of _Compositæ,_ and a curious fern, a variety of _Aristichum aureum._ Towards the northern end of Hattiah, Talipot, cocoa-nut and date-palms appear.

On the 22nd we entered the Sunderbunds, rowing amongst narrow channels, where the tide rises but a few feet. The banks were covered with a luxuriant vegetation, chiefly of small trees, above which rose stately palms. On the 25th, we were overtaken by a steamer from Assam, a novel sight to us, and a very strange one in these creeks, which in some places seemed hardly broad enough for it to pass through. We jumped on board in haste, leaving our boat and luggage to follow us. She had left Dacca two days before, and this being the dry season, the route to Calcutta, which is but sixty miles in a straight line, involved a détour of three hundred.

From the masts of the steamer we obtained an excellent _coup-d’œil_ of the Sunderbunds; its swamps clothed with verdure, and intersected by innumerable inosculating channels, with banks a foot or so high. The amount of tide, which never exceeds ten feet, diminishes in proceeding westwards into the heart of these swamps, and the epoch, direction, and duration of the ebb and flow vary so much in every canal, that at times, after stemming a powerful current, we found ourselves, without materially changing our course, suddenly swept along with a favouring stream. This is owing to the complex ramifications of the creeks, the flow of whose waters is materially influenced by the most trifling accidents of direction.

Receding from the Megna, the water became saltier, and _Nipa fruticans_ appeared, throwing up pale yellow-green tufts of feathery leaves, from a short thick creeping stem, and bearing at the base of the leaves its great head of nuts, of which millions were floating on the waters, and vegetating in the mud. Marks of tigers were very frequent, and the footprints of deer, wild boars, and enormous crocodiles: these reptiles were extremely common, and glided down the mud banks on the approach of the steamer, leaving between the footmarks a deep groove in the mud made by their tail. The _Phœnix paludosa,_ a dwarf slender-stemmed date-palm, from six to eight feet high, is the all-prevalent feature, covering the whole landscape with a carpet of feathery fronds of the liveliest green. The species is eminently gregarious, more so than any other Indian palm, and presents so dense a mass of foliage, that when seen from above, the stems are wholly hidden.[394]

[394] _Sonneratia, Heritiera littoralis,_ and _Careya,_ form small gnarled trees on the banks, with deep shining green-leaved species of _Carallia Rhizophora,_ and other Mangroves. Occasionally the gigantic reed-mace (_Typha elephantina_) is seen, and tufts of tall reeds (_Arundo_).

The water is very turbid, and only ten to twenty feet deep, which, we were assured by the captain, was not increased during the rains: it is loaded with vegetable matter, but the banks are always muddy, and we never saw any peat. Dense fogs prevented our progress in the morning, and we always anchored at dusk. We did not see a village or house in the heart of the Sunderbunds (though such do occur), but we saw canoes, with fishermen, who use the tame otter in fishing; and the banks were covered with piles of firewood, stacked for the Calcutta market. As we approached the Hoogly, the water became very salt and clear; the Nipa fruits were still most abundant, floating out to sea, but no more of the plant itself was seen. As the channels became broader, sand-flats appeared, with old salt factories, and clumps of planted _Casuarina._

On the 28th of January we passed Saugor island, and entered the Hoogly, steamed past Diamond Harbour, and landed at the Botanic Garden Ghat, where we received a hearty welcome from Dr. Falconer. Ten days later we bade farewell to India, reaching England on the 25th of March, 1851.

APPENDIX

A.

METEOROLOGICAL OBSERVATIONS IN BEHAR, AND IN THE VALLEYS OF THE SOANE AND GANGES.

Most of the instruments which I employed were constructed by Mr. Newman, and with considerable care: they were in general accurate, and always extremely well guarded, and put up in the most portable form, and that least likely to incur damage; they were further frequently carefully compared by myself. These are points to which too little attention is paid by makers and by travellers in selecting instruments and their cases. This remark applies particularly to portable barometers, of which I had five at various times. Although there are obvious defects in the system of adjustment, and in the method of obtaining the temperature of the mercury, I found that these instruments invariably worked well, and were less liable to derangement and fracture than any I ever used; the best proof I can give of this is that I preserved three uninjured during nearly all my excursions, left two in India, and brought a third home myself that had accompanied me almost throughout my journey.

In very dry climates these and all other barometers are apt to leak, from the contraction of the box-wood plug through which the tube passes into the cistern. This must, in portable barometers, in very dry weather, be kept moist with a sponge. A small iron bottle of pure mercury to supply leakage should be supplied with every barometer, as also a turnscrew. The vernier plate and scale should be screwed, not soldered on the metal sheath, as if an escape occurs in the barometer-case the solder is acted upon at once. A table of corrections for capacity and capillarity should accompany every instrument, and simple directions, etc., in cases of trifling derangement, and alteration of neutral point.

The observations for temperature were taken with every precaution to avoid radiation, and the thermometers were constantly compared with a standard, and the errors allowed for. The maximum thermometer with a steel index, I found to be extremely liable to derangement and very difficult to re-adjust. Negretti’s maximum thermometer was not known to me during my journey. The spirit minimum thermometers again, are easily set to rights when out of order, but in every one (of six or seven) which I took to India, by several makers, the zero point receded, the error in some increasing annually, even to –6° in two years. This seems due to a vaporisation of the spirit within the tube. I have seen a thermometer of this description in India, of which the spirit seemed to have retired wholly into the bulb, and which I was assured had never been injured. In wet-bulb observations, distilled water or rain, or snow water was used, but I never found the result to differ from that obtained by any running fresh water, except such as was polluted to the taste and eye.

The hours of observation selected were at first sunrise, 9 a.m., 3 p.m., sunset, and 9 p.m., according to the instructions issued to the Antarctic expedition by the Royal Society. In Sikkim, however, I generally adopted the hours appointed at the Surveyor General’s office, Calcutta; viz., sunrise, 9h. 50m. a.m., noon, 2h. 40m. p.m., 4 p.m., and sunset, to which I added a 10 p.m. observation, besides many at intermediate hours as often as possible. Of these the 9h. 50m. a.m. and 4 p.m. have been experimentally proved to be those of the maximum and minimum of atmospheric pressure at the level of the sea in India, and I did not find any great or marked deviation from this at any height to which I attained, though at 15,000 or 16,000 feet the morning maximum may occur rather earlier.

The observations for nocturnal (terrestrial) radiation were made by freely suspending thermometers with naked bulbs, or by laying them on white cotton, wool, or flannel; also by means of a thermometer placed in the focus of a silvered parabolic reflector. I did not find that the reflector possessed any decided advantage over the white cotton: the means of a number of observations taken by each approximated closely, but the difference between individual observations often amounted to 2°.

Observations again indicative of the radiation from grass, whether dewed or dry, are not strictly comparable; not only does the power of radiation vary with the species, but much more with the luxuriance and length of the blades, with the situation, whether on a plane surface or raised, and with the subjacent soil. Of the great effect of the soil I had frequent instances; similar tufts of the same species of grass radiating more powerfully on the dry sandy bed of the Soane, than on the alluvium on its banks; the exposure being equal in both instances. Experiments for the surface-temperature of the soil itself, are least satisfactory of any:—adjoining localities being no less affected by the nature, than by the state of disintegration of the surface, and by the amount of vegetation in proximity to the instrument.

The power of the sun’s rays in India is so considerable, and protracted through so long a period of the day, that I did not find the temperature of springs, or of running water, even of large deep rivers, so constant as was to be expected.

The temperature of the earth was taken by sinking a brass tube a yard long in the soil.

A thermometer with the bulb blackened affords the only means the traveller can generally compass, of measuring the power of the sun’s rays. It should be screened or put in a blackened box, or laid on black wool.

A good Photometer being still a desideratum, I had recourse to the old wedge of coloured glass, of an uniform neutral tint, the distance between whose extremes, or between transparency and total opacity, was one foot. A moveable arm carrying a brass plate with a slit and a vernier, enables the observer to read off at the vanishing point of the sun’s limb, to one five-hundredth of an inch. I generally took the mean of five readings as one, and the mean of five of these again I regarded as one observation; but I place little dependence upon the results. The causes of error are quite obvious. As far as the effects of the sun’s light on vegetation are concerned, I am inclined to think that it is of more importance to register the number of hours or rather of parts of each hour, that the sun shines, and its clearness during the time. To secure valuable results this should be done repeatedly, and the strength of the rays by the black-bulb thermometer registered at each hour. The few actinometer observations will be found in another part of the Appendix.

The dew-point has been calculated from the wet-bulb, by Dr. Apjohn’s formula, or, where the depression of the barometer is considerable, by that as modified by Colonel Boileau.[395] The saturation-point was obtained by dividing the tension at the dew-point by that at the ordinary temperature, and the weight of vapour, by Daniell’s formula.

[395] Journal of Asiatic Society, No. 147 (1844), p.135.

The following summary of meteorological observations is alluded to at vol. i., p. 15.

I.—_Table-land of Birbhoom and Behar, from Taldanga to Dunwah. Average elevation 1,135 feet._

It is evident from these observations, that compared with Calcutta, the dryness of the atmosphere is the most remarkable feature of this table-land, the temperature not being high; and to this, combined with the sterility of the soil over a great part of the surface, must be attributed the want of a vigorous vegetation. Though so favourably exposed to the influence of nocturnal radiation, the amount of the latter is small. The maximum depression of a thermometer laid on grass never exceeded 10°, and averaged 7°; whereas the average depression of the dew-point at the same hour amounted to 25° in the morning. Of course no dew was deposited even in the clearest star-light night.

February 1848 Hour Sunrise 9 a.m. 3 p.m. 9 p.m. TEMPERATURE Mean Max. Min. Range 56·6 65·2 46·3 18·9 70·1 77·0 61·2 15·8 75·5 81·7 65·2 16·5 61·7 66·2 55·5 10·7 WET-BULB Mean Max. Depression Min. Depression 48·2 12·5 6·0 53·7 19·3 14·3 55·3 22·5 16·7 49·3 20·5 9·0 Elasticity of Vapour ·276 ·264 ·248 ·248 DEW-POINT Mean Max. Min. Max. Depression Min. Depression 39·5 52·0 23·3 31·7 10·4 37·9 52·7 24·5 39·2 24·3 36·0 46·8 24·3 48·4 34·9 36·1 50·0 [396]9·1 56·9 16·2 Weight of Vapour in cubic feet 3·088 2·875 2·674 2·745 SATURATION Mean Max. Min. ·550 ·680 ·330 ·330 ·450 ·260 ·260 ·320 ·190 ·410 ·590 ·140 Number of observations 7 7 7 10

Extreme variations of temperature 35·4° Extreme variations of relative humidity ·540 Extreme diff. solar and nocturnal radiation 96·5°

[396] Taken during a violent N.W. dust-storm.

SOLAR RADIATION MORNING Hour Th. Black Bulb Diff. Phot. 9.30 a.m. 10 a.m. 10 a.m. 9 a.m. 9 a.m. 9 a.m. 77·0 69·5 77·0 63·5 61·2 67·0 130 124 137 94 106 114 53·0 54·5 60·0 30·5 44·8 47·0 -- 10·320 -- 10·230 -- 10·350 Mean 69·2 117·5 48·1 10·300

AFTERNOON Hour Th. Black Bulb Diff. Phot. 3.30 p.m. 3 p.m. 3 p.m. 3.30 p.m. 3 p.m. 81·7 80·5 81·5 72·7 72·5 109 120 127 105 110 27·3 39·5 45·5 32·3 37·5 -- 10·320 10·330 10·230 10·390 Mean 77·8 114·2 68·4 10·318

NOCTURNAL RADIATION SUNRISE Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 51·1 4·0 9·0 6 48·3 2·5 3·7 3 46·6 6·2 9·0 5

NINE P.M. Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 56·4 5·3 7·5 7 53·8 4·9 5·5 6 54·4 7·2 10·0 7

On one occasion, and that at night, the dew-point was as low as 11·5°, with a temperature of 66°, a depression rarely equalled at so low a temperature: this phenomenon was transient, and caused by the passage of a current of air loaded with dust, whose particles possibly absorbed the atmospheric humidity. From a comparison of the night and morning observations of thermometers laid on grass, the earth, and freely exposed, it appears that the grass parts with its heat much more rapidly than the earth, but that still the effect of radiation is slight, lowering its temperature but 2° below that of the freely exposed thermometer.

As compared with the climate of Calcutta, these hills present a remarkable contrast, considering their proximity in position and moderate elevation.

The difference of temperature between Calcutta and Birbhoom, deduced from the sunrise, morning and afternoon observations, amounts to 4°, which, if the mean height of the hills where crossed by the road, be called 1,135 feet, will be equal to a fall of one degree for every 288 feet.

In the dampness of its atmosphere, Calcutta contrasts very remarkably with these hills; the dew-point on the Hoogly averaging 51·3°, and on these hills 38°, the corresponding saturation-points being 0·559 and 0·380.

The difference between sunrise, forenoon and afternoon dew-points at Calcutta and on the hills, is 13·6° at each observation; but the atmosphere at Calcutta is relatively drier in the afternoon than that of the hills; the difference between the Calcutta sunrise and afternoon saturation-point being 0·449, and that between the hill sunrise and afternoon, 0·190. The march of the dew-point is thus the same in both instances, but owing to the much higher temperature of Calcutta, and the greatly increased tension of the vapour there, the relative humidity varies greatly during the day.

In other words, the atmosphere of Calcutta is loaded with moisture in the early morning of this season, and is relatively dry in the afternoon: in the hills again, it is scarcely more humid at sunrise than at 3 p.m. That this dryness of the hills is partly due to elevation, appears from the disproportionately moister state of the atmosphere below the Dunwah pass.

II.—_Abstract of the Meteorological observationsctaken in the Soane Valley (mean elevation 422 feet)._

The difference in mean temperature (partly owing to the sun’s more northerly declination) amounts to 2·5° of increase in the Soane valley, above that of the hills. The range of the thermometer from day to day was considerably greater on the hills (though fewer observations were there recorded): it amounted to 17·2° on the hills, and only 12·8° in the valley. The range from the maximum to the minimum of each day amounts to the same in both, above 20°. The extreme variations in temperature too coincide within 1·4°.

The hygrometric state of the atmosphere of the valley differs most decidedly from that of the hills. In the valley dew is constantly formed, which is owing to the amount of moisture in the air, for nocturnal radiation is more powerful on the hills. The sunrise and 9 p.m. observations in the valley, give a mean depression of the dew-point below the air of 12·3°, and those at the upper level of 21·2°, with no dew on the hills and a copious deposit in the valley. The corresponding state of the atmosphere as to saturation is 0·480 on the hills and 0·626 in the valley.

The vegetation of the Soane valley is exposed to a less extreme temperature than that of the hills; the difference between solar and nocturnal radiation amounting here only to 80·5°, and on the hills to 96·5°. There is no material difference in the power of the sun’s rays at the upper and lower levels, as expressed by the blackbulb thermometer, the average rise of which above one placed in the shade, amounted to 48° in both cases, and the maximum occurred about 11 a.m. The decrease of the power of the sun’s rays in the afternoon is much the most rapid in the valley, coinciding with a greater reduction of the elasticity of vapour and of humidity in the atmosphere.

The photometer observations show a greater degree of sun’s light on the hills than below, but there is not at either station a decided relation between the indications of this instrument and the black-bulb thermometer. From observations taken elsewhere, I am inclined to attribute the excess of solar light on the hills to their elevation; for at a far greater elevation I have met with much stronger solar light, in a very damp atmosphere, than I ever experienced in the drier plains of India. In a damp climate the greatest intensity may be expected in the forenoon, when the vapour is diffused near the earth’s surface; in the afternoon the lower strata of atmosphere are drier, but the vapour is condensed into clouds aloft which more effectually obstruct the sun’s rays. On the Birbhoom and Behar hills, where the amount of vapour is so small that the afternoon is but little drier than the forenoon, there is little difference between the solar light at each time. In the Soane valley again, where a great deal of humidity is removed from the earth’s surface and suspended aloft, the obstruction of the sun’s light is very marked.

DUNWAH TO SOANE RIVER, AND UP SOANE TO TURA

February 10–19th Hour Sunrise 9 a.m. 3 p.m. 9 p.m. TEMPERATURE Mean Max. Min. Range 57·6 62·0 53·5 8·5 74·0 81·0 63·5 17·5 77·6 87·5 71·0 16·5 64·5 68·7 60·0 8·7 WET-BULB Mean Max. Depression Min. Depression 51·7 8·5 3·8 59·5 18·5 4·0 59·9 26·0 6·8 55·5 12·5 2·5 Elasticity of Vapour 0·352 0·382 0·357 0·370 DEW-POINT Mean Max. Min. Max. Depression Min. Depression 46·1 53·6 40·6 16·9 7·0 48·5 56·7 38·0 33·5 6·8 46·4 60·0 36·0 44·2 11·0 47·5 55·6 41·0 24·1 4·4 Weight of Vapour in cubic feet 3·930 4·066 3·658 4·014 SATURATION Mean Max. Min. ·680 ·787 ·566 ·460 ·818 ·338 ·352 ·703 ·237 ·572 ·860 ·452 Number of observations 10 8 9 10

Extreme variations of temperature 34·0° Extreme variations of relative humidity ·623 Extreme diff. solar and nocturnal radiation 80·5°

NOCTURNAL RADIATION

SUNRISE Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 53·2 4·5 8·5 9 54·0 3·7 9·0 9 51·5 6·2 7·5 8

NINE P.M. Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 59·9 4·6 11·5 10 60·7 3·8 10·5 10 56·4 8·1 13·5 10

SOLAR RADIATION MORNING Time Th. Black Bulb Diff. Phot. 9 a.m. 11 a.m. 10.30 a.m. 10 a.m. 10 a.m. 10.30 a.m. 70·0 81·0 71·5 72·0 80·0 78·0 125 119 126 117 122 128 55·0 38·0 54·5 45·0 42·0 50·0 10·300 10·230 10·300 10·220 -- -- Mean 75·4 122·8 47·4 10·262

AFTERNOON Time Th. Black Bulb Diff. Phot. 4 p.m. 3 p.m. 3 p.m. 3 p.m. 76·5 80·0 76·0 87·5 90 105 102 126 13·5 25·0 26·0 38·5 -- 10·210 10·170 -- Mean 80·0 105·7 25·7 10·190

NOCTURNAL RADIATION FROM PLANTS SUNRISE NINE P.M. Air temperature 59·5 55·0 67·5 67·0 64·3 Calotropis -- 49·5 -- -- 58·5 Difference -- 5·5 -- -- 5·83 Argemone 57·0 47·0 53·0 56·0 57·0 Difference 2·5 8·0 14·0 11·0 7·3

III.—_VALLEY OF SOANE RIVER, TURA TO SULKUN (Mean elev. 517 feet)_

February 20th to March 3rd Hour Sunrise 9 a.m. 3 p.m. 9 p.m. TEMPERATURE Mean Max. Min. Range 56·8 70·0 50·0 20·0 82·0 89·0 69·0 20·0 88·6 94·7 81·5 13·2 68·0 74·0 61·0 13·0 WET-BULB Mean Max. Depression Min. Depression 52·5 10·0 1·5 61·2 24·3 12·0 62·4 30·2 14·5 56·8 15·0 6·0 Elasticity of Vapour 0·380 0·385 0·289 0·369 DEW-POINT Mean Max. Min. Max. Depression Min. Depression 48·3 53·1 41·1 17·3 5·4 48·7 60·2 40·3 45·2 22·0 40·8 50·9 32·3 57·2 25·1 47·4 51·8 42·6 27·1 10·2 Weight of Vapour in cubic feet 4·240 4·097 2·975 3·933 SATURATION Mean Max. Min. ·754 ·831 ·570 ·342 ·488 ·226 ·211 ·598 ·154 ·511 ·703 ·415 Number of observations 12 11 11 11

Extreme variation of temperature 44·7° Extreme variation of relative humidity ·677 Extreme diff. solar and nocturnal radiation 100°

NOCTURNAL RADIATION

SUNRISE Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 51·7 5·1 8·0 9 52·4 3·4 7·0 9 48·8 7·0 11·5 9

NINE P.M. Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 61·2 6·8 10·5 10 64·3 4·6 8·5 9 55·8 11·8 17·0 9

SOLAR RADIATION MORNING Time Temp. Black Bulb Diff. Phot. 11.30 a.m. 10.30 a.m. Noon Noon Noon Noon 85·5 89·0 90·0 85·0 86·0 90·0 129 132 132 130 138 138 44·5 43·0 42·0 45·0 52·0 48·0 -- -- 10·140 -- -- -- Mean 87·6 133 45·8 10·140

AFTERNOON Time Temp. Black Bulb Diff. Phot. 3 p.m. -- -- -- -- 85·5 92·5 92·0 89·5 93·5 116 128 120 128 144 30·5 35·5 28·0 38·5 50·5 -- -- -- -- -- Mean 90·6 127 36·6 --

NOCTURNAL RADIATION FROM PLANTS SUNRISE Air temperature Barley Diff. Calo- tropis Diff. Arge- mone Diff. 61·0 57·0 57·0 58·5 57·0 50·0 50·5 56·0 56 46 52 52 52 45 43 -- 5·0 11·0 5·0 6·5 5·0 5·0 7·5 -- 56·5 48·0 -- -- -- 45·5 -- -- 4·5 9·0 -- -- -- 4·5 -- -- 57·0 50·0 50·0 -- -- -- -- 49·0 4·0 7·0 7·0 -- -- -- -- 7·0 55·9 49·4 6·4 50·0 6·0 51·5 6·2 NINE P.M. Air temperature Barley Diff. Calo- tropis Diff. Arge- mone Diff. 68·5 70·0 69·0 74·0 62·5 67·5 61·0 -- -- -- -- 51·5 67·5 50·0 -- -- -- -- 11·0 10·0 11·0 -- 65·0 57·0 59·0 -- 62·5 -- -- 5·0 12·0 15·0 -- 5·0 -- 56·0 67·0 57·0 -- -- -- -- 12·5 3·0 12·0 -- -- -- -- 67·5 56·3 10·7 60·9 9·3 60·0 9·2

The upper course of the Soane being in some places confined, and exposed to furious gusts from the gullies of the Kymore hills, and at others expanding into a broad and flat valley, presents many fluctuations of temperature. The mean temperature is much above that of the lower parts of the same valley (below Tura), the excess amounting to 5.4°. The nights and mornings are cooler, by 1·2°, the days hotter by 10°. There were also 10° increase of range during the thirteen days spent there; and the mean range from day to day was nearly as great as it was on the hills of Bengal.

There being much exposed rock, and the valley being swept by violent dust-storms, the atmosphere is drier, the mean saturation point being ·454, whereas in the lower part of the Soane’s course it was ·516.

A remarkable uniformity prevails in the depression of thermometers exposed to nocturnal radiation, whether laid on the earth, grass, or freely exposed; both the mean and maximum indication coincide very nearly with those of the lower Soane valley and of the hills. The temperature of tufts of green barley laid on the ground is one degree higher than that of short grass; _Argemone_ and _Calotropis_ leaves maintain a still warmer temperature; from the previous experiments the _ Argemone_ appeared to be considerably the cooler, which I was inclined to attribute to the smoother and more shining surface of its leaf, but from these there would seem to be no sensible difference between the radiating powers of the two plants.

IV.—_TABLE-LAND OF KYMORE HILLS (Mean elev. 979 feet)_

February 20th to March 3rd Hour Sunrise 9 a.m. 3 p.m. 9 p.m. TEMPERATURE Mean Max. Min. Range 65·3 69·0 57·5 11·5 81·6 83·5 79·5 4·0 88·1 90·0 84·5 5·5 71·1 76·0 68·0 8·0 WET-BULB Mean Max. Depression Min. Depression 57·7 8·0 6·0 65·3 19·0 14·0 63·3 26·5 21·5 60·3 13·0 8·3 Elasticity of Vapour 0·428 0·468 0·324 0·433 DEW-POINT Mean Max. Min. Max. Depression Min. Depression 52·0 55·5 45·9 14·1 11·6 54·5 57·9 49·0 33·0 12·9 43·7 47·8 37·9 46·6 42·2 52·3 56·7 46·8 21·9 13·8 Weight of Vapour in cubic feet 4·710 5·000 3·417 4·707 SATURATION Mean Max. Min. ·647 ·741 ·648 ·421 ·479 ·344 ·240 ·295 ·214 ·542 ·643 ·491 Number of observations 4 3 3 4

Extreme variation of temperature 32·5° Extreme variation of relative humidity ·527 Extreme diff. solar and nocturnal radiation 110·5°

NOCTURNAL RADIATION

SUNRISE Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 59·5 3·5 3·5 2 56·0 1·5 1·5 1 54·7 8·2 8·5 2

NINE P.M. Exposed thermometer On earth On grass Temperature Mean diff. from air Max. diff. from air Number of observations 71·5 3·3 7·0 3 62·5 5·5 5·5 1 61·0 8·2 11·0 2

The rapid drying of the lower strata of the atmosphere during the day, as indicated by the great decrease in the tension of the vapour from 9 a.m. to 3 p.m., is the effect of the great violence of the north-west winds.

From the few days’ observations taken on the Kymore hills, the temperature of their flat tops appeared 5° higher than that of the Soane valley, which is 500 feet below their mean level. I can account for this anomaly only on the supposition that the thick bed of alluvium, freely exposed to the sun (not clothed with jungle), absorbs the sun’s rays and parts with its heat slowly. This is indicated by the increase of temperature being due to the night and morning observations, which are 3·1° and 8·5° higher here than below, whilst the 9 a.m. and 3 p.m. temperatures are half a degree lower.

The variations of temperature too are all much less in amount, as are those of the state of the atmosphere as to moisture, though the climate is rather damper.

On the subject of terrestrial radiation the paucity of the observations precludes my dwelling. Between 9 p.m. and sunrise the following morning I found the earth to have lost but 6·5° of heat, whereas a mean of nine observations at the same hours in the valley below indicated a loss of 12°.

Though the mean temperature deduced from the few days I spent on this part of the Kymore is so much above that of the upper Soane valley, which it bounds, I do not suppose that the whole hilly range partakes of this increase. When the alluvium does not cover the rock, as at Rotas and many other places, especially along the southern and eastern ridges of the ghats, the nights are considerably cooler than on the banks of the Soane; and at Rotas itself, which rises almost perpendicularly from the river, and is exposed to no such radiation of heat from a heated soil as Shahgunj is, I found the temperature considerably below that of Akbarpore on the Soane, which however is much sheltered by an amphitheatre of rocks.

V.—_Mirzapore on the Ganges._

During the few days spent at Mirzapore, I was surprised to find the temperature of the day cooler by nearly 4° than that of the hills above, or of the upper part of the Soane valley, while the nights on the other hand were decidedly warmer. The dew-point was even lower in proportion, 7·6°, and the climate consequently drier. The following is an abstract of the observations taken at Mr. Hamilton’s house on the banks of the Ganges (p. 363).

It is remarkable that nocturnal radiation as registered at sunrise is much more powerful at Mirzapore than on the more exposed Kymore plateau; the depression of the thermometer freely exposed being 3° greater, that laid on bare earth 6°, and that on the grass 1·4° greater, on the banks of the Ganges.

During my passage down the Ganges the rise of the dew-point was very steady, the maximum occurring at the lowest point on the river, Bhaugulpore, which, as compared with Mirzapore, showed an increase of 8° in temperature, and of 30·6° in the rise of the dew-point. The saturation-point at Mirzakore was ·331, and at the corresponding hours at Bhaugulpore ·742.

MIRZAPORE (Mean elev. 362 feet)

March 9th to 13th, 1848 Hour Sunrise 9 a.m. 3 p.m. 9 p.m. TEMPERATURE Mean Max. Min. Range 61·1 63·0 58·0 5·0 76·1 83·0 71·0 12·0 86·0 -- -- -- 76·0 -- -- -- WET-BULB Mean Max. Depression Min. Depression 48·8 51·5 47·0 58·5 56·5 51·7 61·7 24·3 -- 63·5 12·5 -- Elasticity of Vapour ·236 ·302 ·295 ·480 DEW-POINT Mean Max. Min. Max. Depression Min. Depression 34·3 39·7 29·7 32·8 23·8 41·9 -- -- 52·3 15·7 41·3 -- -- 44·7 -- 55·2 -- -- 20·8 -- Weight of Vapour in cubic feet 2·574 3·271 3·089 5·127 SATURATION Mean Max. Min. ·405 ·450 ·327 ·324 ·603 ·176 ·264 -- -- ·511 -- -- Number of observations 3 3 1 1

Air in shade Sunrise Exposed Therm. Diff. Exposed on earth Diff. Exposed on grass Diff. 60·0 62·5 63·0 58·0 55·0 54·5 55·5 53·0 5·0 8·0 7·5 5·0 -- 56·0 50·5 54·0 -- 6·5 12·5 4·0 52·0 52·5 50·5 50·0 8·0 10·0 12·5 8·0 60·9 54·6 6·4 53·5 7·7 51·3 9·6

B.

ON THE MINERAL CONSTITUENTS AND ALGÆ OF THE HOT-SPRINGS OF BEHAR, THE HIMALAYA, AND OTHER PARTS OF INDIA, ETC., INCLUDING NOTES ON THE FUNGI OF THE HIMALAYA.

(By Dr. R. D. Thomson and the Rev. M. J. Berkeley, M.A., F.L.S.)

The following remarks, for which I am indebted to the kindness of the able chemist and naturalist mentioned above, will be highly valued, both by those who are interested in the many curious physiological questions involved in the association of the most obscure forms of vegetable life with the remarkable phenomena of mineral springs; or in the exquisitely beautiful microscopic structure of the lower Algæ, which has thrown so much light upon a branch of natural history, whose domain, like that of astronomy, lies to a great extent beyond the reach of the unassisted eye.—J.D.H.

1. Mineral water, Soorujkoond, Behar (vol. i., p. 27), contains chloride of sodium and sulphate of soda.

2. Mineral water, hot springs, Yeumtong, altitude 11,730 feet (see vol. ii., p. 117). Disengages sulphuretted hydrogen when fresh.—This water was inodorous when the bottle was opened. The saline matter in solution was considerably less than in the Soorujkoond water, but like that consisted of chloride of sodium and sulphate of soda. Its alkaline character suggests the probability of its containing carbonate of soda, but none was detected. The rocks decomposed by the waters of the spring consist of granite impregnated with sulphate of alumina. It appears that in this case the sulphurous waters of Yeumtong became impregnated in the air with sulphuric acid, which decomposed the felspar,[397] and united with its alumina. I found traces only of potash in the salt.

[397] I have, in my journal, particularly alluded to the garnets (an aluminous mineral) being thus entirely decomposed.—J.D.H.

Sulphuretted hydrogen waters appear to give origin to sulphuric acid, when the water impregnated with the gas reaches the surface; and I have fine fibrous specimens of sulphate of lime accompanied with sulphur, from the hot springs of Pugha in west Tibet, brought by Dr. T. Thomson.

3. Mineral water, Momay hot springs, (vol. ii., p. 133).—When the bottle was uncorked, a strong smell of sulphuretted hydrogen was perceived. The water contains about twenty-five grains per imp. gallon, of chloride of sodium, sulphate and carbonate of soda; the reaction being strongly alkaline when the solution was concentrated.

4. Effloresced earth from Behar (vol. i., p. 13), consists of granite sand, mixed with sesquicarbonate of soda.

_On the Indian Algæ which occur principally in different parts of the Himalayan Range, in the hot-springs of Soorujkoond in Bengal, Pugha in Tibet, and Momay in Sikkim; and on the Fungi of the Himalayas._ By the Rev. M. J. Berkeley, M.A.

It is not my intention in the present appendix to give specific characters or even accurately determined specific names to the different objects within its scope, which have come under investigation, as collected by Dr. Hooker and Dr. Thomson. To do so would require far more time than I have at present been able to devote to the subject, for though every species has been examined microscopically, either by myself or Mr. Broome, and working sketches secured at the same time, the specific determination of fresh water Algæ from Herbarium specimens is a matter which requires a very long and accurate comparison of samples from every available locality, and in the case of such genera as _Zygnema, Tyndaridea,_ and _Conferva,_ is, after all, not a very satisfactory process.

The object in view is merely to give some general notion of the forms which presented themselves in the vast districts visited by the above-mentioned botanists, comprising localities of the greatest possible difference as regards both temperature and elevation; but more especially in the hot-springs which occur in two distant parts of the Himalayas and in Behar, and these again under very different degrees of elevation and of extrinsic temperature.

The Algæ from lower localities are but few in number, and some of these of very common forms. We have for instance from the Ganges, opposite Bijnour, a _ Batrachospermum_ and _Conferva crispata,_ the former purple below, with specimens of _Chantransia,_ exactly as they might occur in the Thames. The _Conferva,_ or more properly _ Cladophora,_ which occurs also under various forms, at higher elevations, as in the neighbourhood of Simla and Iskardo, swarms with little parasites, but of common or uninteresting species. In the Bijnour specimens, these consist of common forms of _Synedra, Meridion circulare,_ and a _Cymbella,_ on others from Dacca, there are about three species of _Synedra,_[398] a minute _Navicula_ and _Gomphonema curvatum._ Nothing, in fact, can well be more European. One splendid Alga, however, occurs at Fitcoree, in Behar, on the banks of nullahs, which are dry in hot weather, forming a purple fleece of coarse woolly hairs, which are singularly compressed, and of extreme beauty under the microscope, from the crystalline green of the articulated string which threads the bright red investing sheath. This curious Alga calls to mind in its colouring _Cænocoleus Smithii,_ figured in English Botany, t. 2940, but it has not the common sheath of that Alga, and is on a far larger scale. One or two other allied forms, or species, occur in East Nepal, to which I purpose giving, together with the Behar plant, the generic name of _Erythronema._ From the Soane River, also, is an interesting Alga, belonging to the curious genus _Thwaitesia,_ in which the division of the endochrome in the fertile cells into four distinct masses, sometimes entirely free, is beautifully marked. In some cases, indeed, instead of the ordinary spores, the whole moss is broken up into numerous bodies, as in the fertile joints of _Ulothrix,_ and probably, as in that case, the resultant corpuscles are endowed with active motion. In Silhet, again, is a magnificent _ Zygnema,_ allied to _Z. nitidum,_ with large oval spores, about 1/285 part of an inch long, and a dark golden brown colour, and containing a spiral green endochrome.

[398] Two of these appear to be _S. Vaucheriæ_ and _S. inæqualis._

Leaving, however, the lower parts of India, I shall first take the species which occur in Khasia, Sikkim, Eastern Nepal, and the adjoining parts of Tibet.

In the hot valleys of the Gtreat Rungeet, at an elevation of about 2000 feet, we have the _Erythronema,_ but under a slightly different form; at Nunklow, at about the same height; in Khasia, again, at twice that elevation; in Eastern Nepal, at 12,000; and, finally, at Momay, reaching up to 16,000 feet. In water, highly impregnated with oxide of iron, at 4000 feet in Sikkim, a _Leptothrix_ occurred in great abundance, coloured with the oxide, exactly as is the case with Algæ which grow in iron springs in Europe. At elevations between 5000 and 7000 feet, several European forms occur, consisting of _ Ulothrix, Zygnema, Oscillatoria, Lyngbya, Sphærozyga, Scytonema, Conferva,_ and _Cladophora._ The species may indeed not be identical with European species, but they are all more or less closely allied to well-known Hydrophytes. One very interesting form, however, either belonging to the genus _ Zygnema,_ or possibly constituting a distinct genus, occurs in streams at 5000 feet in Sikkim, consisting of highly gelatinous threads of the normal structure of the _Zygnema,_ but forming a reticulated mass. The threads adhere to each other laterally, containing only a single spiral endochrome, and the articulations are very long. Amongst the threads are mixed those of some species of _Tyndaridea._ There is also a curious _Hormosiphon,_ at a height of 7000 feet; forming anastomosing gelatinous masses. A fine new species of _Lyngbya_ extends up as high as 11,000 feet. At 13,000 feet occurs either some simple _Conferva_ or _Zygnema,_ it is doubtful which from the condition of the specimens; and at the same elevation, in the nearly dry bed of the stream which flows from the larger lake at Momay, amongst flat cakes, consisting of felspathic silt from the glaciers above, and the débris of Algæ, and abounding in Diatomaceæ, some threads of a _Zygnema._ At 17,000 feet, an _ Oscillatoria,_ attached or adherent to _Zannichellia_; and, finally, on the bare ground, at 18,000 feet, on the Donkia mountains, an obscure species of _Cænocoleus._ On the surface of the glaciers at Kinchinjhow, on silt, there is a curious _Palmella,_ apparently quite distinct from any European form.

Amongst the greater part of the Algæ, from 4000 feet to 18,000 feet, various Diatomaceæ occur, which will be best noticed in a tabular form, as follows; the specific name, within brackets, merely indicating the species to which they bear most resemblance:—

Himantidium (_Soleirolii_) Odontidium (_hiemale,_ forma minor) Epithemia, _n. sp._ Cymbella Navicula, _n. sp._ Tabillaria (_flocculosa_ Odontidium (_hiemale_) Himantidium Odontidium (_turgidulum_) Epithemia (_ocellata_) Fragillaria Odontidium (_turgidulum_) Dictyocha (_gracilis_) Odontidium (_hiemale_) 4000 to 7000 feet 5000 to 7000 feet 7000 feet — — 6000 to 7000 feet 11,000 feet 16,000 feet 17,000 feet — 18,000 feet — — — Sikkim Sikkim Sikkim Sikkim Sikkim Sikkim Sikkim Momay Momay Tibet Momay Momay Momay Kinchinjhow

We now turn to those portions of Tibet or the neighbouring regions, explored by Dr. Thomson and Captain Strachey. The principal feature in the Algology is the great prevalence of species of _Zygnema_ and _Tyndaridea,_ which occur under a variety of forms, sometimes with very thick gelatinous coats. In not a single instance, however, is there the slightest tendency to produce fructification. _Conferva crispata_ again, as mentioned above, occurs in several localities; and in one locality a beautiful unbranched _Conferva,_ with torulose articulations. At Iskardo, Dr. Thomson gathered a very gelatinous species of _Draparnaldia,_ or more properly, a _ Stygeoclonium,_ if we may judge from a little conglomeration of cells which appeared amongst the threads. A _Tetraspora_ in Piti, an obscure _Tolypothrix,_ and one or two _ Oscillatoriæ,_ remarkable for their interrupted mode of growth, complete the list of Algæ, with the exception of one, to be mentioned presently; as also of _Diatomaceæ,_ and of the species of _Nostoc_ and _Hormosiphon,_ which occurred in great profusion, and under several forms, sometimes attaining a very large size (several inches across), especially in the districts of Le and Piti, and where the soil or waters were impregnated with saline matters. It is well known that some species of _Nostoc_ form an article of food in China, and one was used for that purpose in a late Arctic expedition, as reported by Dr. Sutherland; but it does not seem that any use is made of them in Tibet, though probably all the large species would form tolerable articles of food, and certainly, from their chemical composition, prove very nutritious. One species is mentioned by Dr. Thomson as floating, without any attachment, in the shallow water of the pools scattered over the plains, on the Parang River, separated only by a ridge of mountains from Piti, broad and foliaceous, and scarcely different from the common _ Nostoc,_ which occurs in all parts of the globe. I must not, however, neglect to record a very singular new genus, in which the young threads have the characters of _Tyndaridea,_ but, after a time, little swellings occur on their sides, in which a distinct endochrome is formed, extending backwards into the parent endochrome, separated from it by a well defined membrane, and producing, either by repeated pullulation, a compound mass like that of _Calothrix,_ or simply giving rise to a forked thread. In the latter case, however, there is no external swelling, but a lateral endochrome is formed, which, as it grows, makes its way through an aperture, whose sides are regularly inflected. I have given to this curious production the name of _Cladozygia Thomsoni._

The whole of the above Algæ occurred at heights varying from 10,000 to 15,500 feet. As in the Southern Himalayan Algæ, the specimens were infested with many Diatomaceæ, amongst which the most conspicuous were various _Cymbellæ_ and _Epithemiæ._ The following is a list of the species observed.

Cymbella (_gastroides_). Cymbella (_gracilis_). Cymbella (_Ehrenbergii_) and three others. Odontidium (_hiemale_). Odontidium (_mesodon_). Odontidium _n. sp._ Epithemia _n. sp._ Synedra (_arcus_). Synedra (_tenuis_). Synedra (_æqualis_). Denticula (_obtusa_). Gomphonema (_abbreviatum_). Meridion circulare.

There is very little identity between this list and that before given from the Southern Himalayas, as is the case also with the other Algæ. Till the species, however, have been more completely studied, a very accurate comparison cannot be made.

In both instances the species which grow in hot springs have been reserved in order to make their comparison more easy. I shall begin in an inverse order, with those of the springs of Pugha in Tibet, which attain a temperature of 174°. Two _ Confervæ_ only occur in the specimens which have been preserved, viz., an _Oscillatoria_ allied to that which I have called _O. interrupta,_ and a true _Conferva_ extremely delicate with very long articulations, singularly swollen at the commissures. The _Diatomaceæ_ are:—

Odontidium (_hiemale_). Odontidium (_mesodon_). Odontidium _n. sp.,_ same as at Piti on _Conferva._ Denticula (_obtusa_). Navicula. Cymbella, three species. Epithemia.

Scarcely any one of these except the _Navicula_ is peculiar to the locality. A fragment apparently of some _ Closterium,_ the only one which I have met with in the collection, accompanies one of the specimens.

The hot springs of Momay, (temp. 110°) at 16,000 feet, produce a golden brown _Cænocoleus_ representing a small form of _C. cirrhosus,_ and a very delicate _ Sphærozyga,_ an _Anabaina,_ and _Tolypothrix_; and at 17,000 feet, a delicate green _Conferva_ with long even articulations. With the latter is an _Odontidium_ allied to, or identical with _O. turgidulum,_ and with the former a fine species of _Epithemia_ resembling in form, but not in marking, _E. Faba, E. (Zebra)_ a fine _Navicula,_ perhaps the same with _N. major_ and _Fragilaria (virescens)._[399] In mud from one of the Momay springs (_a_), I detected _Epithemia (Broomeii n.s.),_ and two small _Naviculæ,_ and in the spring (_c_) two species of _Epithemia_ somewhat like _E. Faba,_ but different from that mentioned above.

[399] Mr. Thomas Brightwell finds in a portion of the same specimen _Epithemia alpestris, Surirella splendida, S. linearis,_ Smith, _Pinnularia viridis,_ Smith, _Navicula (lanceolata)_ and _Himantidium (arcus)._

The hot springs of Soorujkoond, of the vegetation of which very numerous specimens have been preserved, are extremely poor in species. In the springs themselves and on their banks, at temperatures varying from 80° to 158°, at which point vegetation entirely ceases, a minute _Leptothrix_ abounds everywhere, varying a little in the regularity of the threads in different specimens, but scarcely presenting two species. Between 84° and 112° there is an imperfect _Zygnema_ with very long articulations, and where the green scum passes into brown, there is sometimes an _Oscillatoria,_ of a very minute stellate _Scytonema,_ probably in an imperfect state. _ Epithemia ocellata_ also contributes often to produce the tint. An _Anabaina_ occurs at a temperature of 125°, but the same species was found also in the stream from the springs where the water had become cold, as was also the case with the _ Zygnema._

The Diatomaceæ consisted of:—

Epithemia Broomeii, _n. s._ Epithemia thermalis, _n. sp._ Epithemia inæqualis, _n. sp._ Navicula Beharensis, _n. sp._

The vegetation in the three sets of springs was very different. As regards the _Confervæ,_ taking the word in its older sense, the species in the three are quite different, and even in respect of genera there is little identity, but amongst the _Diatomaceæ_ there is no striking difference, except in those of the Behar springs where three out of the four did not occur elsewhere. In the Pugha and Momay springs, the species were either identical with, or nearly allied to those found in neighbouring localities, where the water did not exceed the ordinary temperature. A longer examination will doubtless detect more numerous forms, but those which appear on a first examination are sure to give a pretty correct general notion of the vegetation. The species are certainly less numerous than I had expected, or than might be supposed from the vegetation of those European hot springs which have been most investigated.

In conclusion, I shall beg to add a few words on the Fungi of the Himalayas, so far as they have at present been investigated. As regards these there is a marked difference, as might be anticipated from the nature of the climates between those parts of Tibet investigated by Dr. Thomson, and the more southern regions. The fungi found by Dr. Thomson were but few in number, and for the most part of very ordinary forms, differing but little from the produce of an European wood. Some, however, grow to a very large size, as for instance, _Polyporus fomentarius_ on poplars near Iskardo, exceeding in dimensions anything which this species exhibits in Europe. A very fine _Æcidium_ also infests the fir trees (_Abies Smithiana_), a figure of which has been given in the “Gardeners’ Chronicle,” 1852, p. 627, under the name of _Æcidium Thomsoni._ This is allied to the Hexenbesen of the German forests, but is a finer species and quite distinct. _Polyporus oblectans, Geaster limbatus, Geaster mammosus, Erysiphe taurica,_ a _Boletus_ infested with _Sepedonium mycophilum, Scleroderma verrucosum,_ an _Æcidium,_ and a _Uromyces,_ both on _Mulgedium Tataricum,_ about half-a-dozen Agarics, one at an altitude of 16,000 feet above the Nubra river, a _Lycoperdon,_ and _ Morchella semilibera,_ which is eaten in Kashmir, and exported when dry to the plains of India, make up the list of fungi.

The region of Sikkim is perhaps the most productive in fleshy fungi of any in the world, both as regards numbers and species, and Eastern Nepal and Khasia yield also an abundant harvest. The forms are for the most part European, though the species are scarcely ever quite identical. The dimensions of many are truly gigantic, and many species afford abundant food to the natives. Mixed with European forms a few more decidedly tropical occur, and amongst those of East Nepal is a _Lentinus_ which has the curious property of staining every thing which touches it of a deep rhubarb yellow, and is not exceeded in magnificence by any tropical species. The _Polypori_ are often identical with those of Java, Ceylon, and the Philippine Isles, and the curious _Trichocoma paradoxum_ which was first found by Junghuhn in Java, and very recently by Dr. Harvey in Ceylon, occurs abundantly on the decayed trunks of laurels, as it does in South Carolina. The curious genus _Mitremyces_ also is scattered here and there, though not under the American form, but that which occurs in Java. Though _Hymenomycetes_ are so abundant, the _ Discomycetes_ and _Ascomycetes_ are comparatively rare, and very few species indeed of _Sphœria_ were gathered. One curious matter is, that amongst the very extensive collections which have been made there is scarcely a single new genus. The species moreover in Sikkim are quite different, except in the case of some more or less cosmopolite species from those of Eastern Nepal and Khasia: scarcely a single _Lactarius_ or _ Cortinarius_ for instance occurs in Sikkim, though there are several in Khasia. The genus _Boletus_ through the whole district assumes the most magnificent forms, which are generally very different from anything in Europe.

C.

ON THE SOILS OF SIKKIM.

There is little variety in the soil throughout Sikkim, and, as far as vegetation is concerned, it may be divided into vegetable mould and stiff clay—each, as they usually occur, remarkably characteristic in composition of such soils. Bog-earth is very rare, nor did I find peat at any elevation.

The clay is uniformly of great tenacity, and is, I believe, wholly due to the effect of the atmosphere on crumbling gneiss and other rocks. It makes excellent bricks, is tenacious, seldom friable, and sometimes accumulated in beds fourteen feet thick, although more generally only about two feet. In certain localities, beds or narrow seams of pure felspathic clay and layers of vegetable matter occur in it, probably wholly due to local causes. An analysis of that near Dorjiling gives about 30 per cent. of alumina, the rest being silica, and a fraction of oxide of iron. Lime is wholly unknown as a constituent of the soil, and only occasionally seen as a stalactitic deposit from a few springs.

A layer of vegetable earth almost invariably covers the clay to the depth of from three to twelve or fourteen inches. It is a very rich black mould, held in its position on the slopes of the hills by the dense vegetation, and accumulated on the banks of small streams to a depth at times of three and four feet. The following is an analysis of an average specimen of the surface-soil of Dorjiling, made for me by my friend C. J. Muller, Esq., of that place:—

_a._—DRY EARTH

Anhydrous Water 83·84 16·16 ———— 100·00

_b._—ANHYDROUS EARTH

Humic acid Humine Undecomposed vegetable matter Peroxide of iron and manganese Alumina Siliceous matter, insoluble in dilute hydrochloric acid Traces of soda and muriatic acid 3·89 4·61 20·98 7·05 8·95 54·52 -- ———— 100·00

_c._—Soluble in water, gr. 1·26 per cent., consisting of soda, muriatic acid, organic matter, and silica.

The soil from which this example was taken was twelve inches deep; it abounded to the eye in vegetable matter, and was siliceous to the touch. There were no traces of phosphates or of animal matter, and doubtful traces of lime and potash. The subsoil of clay gave only 5·7 per cent. of water, and 5·55 of organic matter. The above analysis was conducted during the rainy month of September, and the sample is an average one of the surface-soil at 6000 to 10,000 feet. There is, I think, little difference anywhere in the soils at this elevation, except where the rock is remarkably micaceous, or where veins of felspathic granite, by their decomposition, give rise to small beds of kaolin.

D. (Vol. i., p. 37)

AN AURORA SEEN FROM BAROON ON THE EAST BANK OF THE SOANE RIVER. Lat. 24° 52′ N.; Long. 84° 22′ E.; Alt. 345 feet.

The following appearances are as noted in my journal at the time. They so entirely resembled auroral beams, that I had no hesitation in pronouncing them at the time to be such. This opinion has, however, been dissented from by some meteorologists, who consider that certain facts connected with the geographical distribution of auroras (if I may use the term), are opposed to it. I am well aware of the force of these arguments, which I shall not attempt to controvert; but for the information of those who may be interested in the matter, I may remark, that I am very familiar with the Aurora borealis in the northern temperate zone, and during the Antarctic expedition was in the habit of recording in the log-book the appearance presented by the Aurora australis. The late Mr. Williams, Mr. Haddon, and Mr. Theobald, who were also witnesses of the appearances on this occasion, considered it a brilliant display of the aurora.

_Feb. 14th,_ 9 p.m.—Bax. Corr. 29·751; temp. 62°; D.P. 41·0°; calm, sky clear; moon three-quarters full, and bright.

Observed about thirty lancet beams rising in the north-west from a low luminous arch, whose extremes bore W. 20° S., and N. 50° E.; altitude of upper limb of arch 20°, of the lower 8°. The beams crossed the zenith, and converged towards S. 15° E. The extremity of the largest was forked, and extended to 25° above the horizon in the S.E. by S. quarter. The extremity of the centre one bore S. 50° E., and was 45° above the horizon. The western beams approached nearest the southern horizon. All the beams moved and flashed slowly, occasionally splitting and forking, fading and brightening; they were brightly defined, though the milky way and zodiacal light could not be discerned, and the stars and planets, though clearly discernible, were very pale.

At 10 p.m., the luminous appearance was more diffused; upper limb of the arch less defined; no beams crossed the zenith; but occasionally beams appeared there and faded away.

Between 10 and 11, the beams continued to move and replace one another, as usual in auroras, but disappeared from the south-east quarter, and became broader in the northern hemisphere; the longest beams were near the north and north-east horizon.

At half-past 10, a dark belt, 4° broad, appeared in the luminous arch, bearing from N. 55° W. to N. 10° W.; its upper limb was 10° above the horizon: it then gradually dilated, and thus appeared to break up the arch. This appeared to be the commencement of the dispersion of the phenomenon.

At 10.50 p.m. the dark band had increased so much in breadth that the arch was broken up in the north-west, and no beams appeared there. Eighteen linear beams rose from the eastern part of the arch, and bore from north to N. 20° E.

Towards 11 p.m., the dark band appeared to have replaced the luminous arch; the beams were all but gone, a few fragments appearing in the N.E. A southerly wind sprang up, and a diffused light extended along the horizon.

At midnight, I saw two faint beams to the north-east, and two well defined parallel ones in the south-west.

E.

PHYSICAL GEOGRAPHY OF THE SIKKIM HIMALAYA, EAST NEPAL, AND ADJACENT PROVINCES OF TIBET.

Sikkim is included in a section of the Himalaya, about sixty miles broad from east to west, where it is bounded respectively by the mountain states of Bhotan and Nepal. Its southern limits are easily defined, for the mountains rise abruptly from the plains of Bengal, as spurs of 6000 to 10,000 feet high, densely clothed with forest to their summits. The northern and north-eastern frontier of Sikkim is beyond the region of much rain, and is not a natural, but a political line, drawn between that country and Tibet. Sikkim lies nearly due north of Calcutta, and only four hundred miles from the Bay of Bengal; its latitude being 26° 40′ to 28° N., and longitude 88° to 89° E.

The main features of Sikkim are Kinchinjunga, the loftiest hitherto measured mountain, which lies to its north-west, and rises 28,178 feet above the level of the sea; and the Teesta river, which flows throughout the length of the country, and has a course of upwards of ninety miles in a straight line. Almost all the sources of the Teesta are included in Sikkim; and except some comparatively insignificant streams draining the outermost ranges, there are no rivers in this country but itself and its feeders, which occupy the largest of the Himalayan valleys between the Tambur in East Nepal, and the Machoo in Western Bhotan.

An immense spur, sixty miles long, stretches south from Kinchin to the plains of India; it is called Singalelah, and separates Sikkim from East Nepal; the waters from its west flank flow into the Tambur, and those from the east into the Great Rungeet, a feeder of the Teesta. Between these two latter rivers is a second spur from Kinchinjunga, terminating in Tendong.

The eastern boundary of Sikkim, separating it from Bhotan, is formed for the greater part by the Chola range, which stretches south from the immense mountain of Donkia, 23,176 feet high, situated fifty miles E.N.E. of Kinchinjunga: where the frontier approaches the plains of India, the boundary line follows the course of the Teesta, and of the Rinkpo, one of its feeders, flowing from the Chola range. This range is much more lofty than that of Singalelah, and the drainage from its eastern flank is into the Machoo river, the upper part of whose course is in Tibet, and the lower in Bhotan.

The Donkia mountain, though 4000 feet lower than Kinchin, is the culminant point of a much more extensive and elevated mountain mass. It throws off an immense spur from its north-west face, which runs west, and then south-west, to Kinchin, forming the watershed of all the remote sources of the Teesta. This spur has a mean elevation of 18,000 to 19,000 feet, and several of its peaks (of which Chomiomo is one) rise much higher. The northern boundary of Sikkim is not drawn along this, but runs due west from Donkia, following a shorter, but stupendous spur, called Kinchinjhow; whence it crosses the Teesta to Chomiomo, and is continued onwards to Kinchinjunga.

Though the great spur connecting Donkia with Kinchin is in Tibet, and bounds the waters that flow directly south into the Teesta, it is far from the true Himalayan axis, for the rivers that rise on its northern slope do not run into the valley of the Tsampu, or Tibetan Burrampooter, but into the Arun of Nepal, which rises to the north of Donkia, and flows south-west for many miles in Tibet, before entering Nepal and flowing south to the Ganges.

Sikkim, thus circumscribed, consists of a mass of mountainous spurs, forest-clad up to 12,000 feet; there are no flat valleys or plains in the whole country, no lakes or precipices of any consequence below that elevation, and few or no bare slopes, though the latter are uniformly steep. The aspect of Sikkim can only be understood by a reference to its climate and vegetation, and I shall therefore take these together, and endeavour, by connecting these phenomena, to give an intelligible view of the main features of the whole country.[400]

[400] This I did with reference especially to the cultivation of Rhododendrons, in a paper which the Horticultural Society of London did me the honour of printing. Quarterly Journ. of Hort. Soc., vol. vii., p. 82.

The greater part of the country between Sikkim and the sea is a dead level, occupied by the delta of the Ganges and Burrampooter, above which the slope is so gradual to the base of the mountains, that the surface of the plain from which the Himalayas immediately rise is only 300 feet above the sea. The most obvious effect of this position is, that the prevailing southerly wind reaches the first range of hills, loaded with vapour. The same current, when deflected easterly to Bhotan, or westerly to Nepal and the north-west Himalaya, is intercepted and drained of much moisture, by the Khasia and Garrow mountains (south of Assam and the Burrampooter) in the former case, and the Rajmahal hills (south of the Ganges) in the latter. Sikkim is hence the dampest region of the whole Himalaya.

Viewed from a distance on the plains of India, Sikkim presents the appearance—common to all mountainous countries—of consecutive parallel ridges, running east and west: these are all wooded, and backed by a beautiful range of snowy peaks, with occasional breaks in the foremost ranges, through which the rivers debouch. Any view of the Himalaya, especially at a sufficient distance for the remote snowy peaks to be seen overtopping the outer ridges, is, however, rare, from the constant deposition of vapours over the forest-clad ranges during the greater part of the year, and the haziness of the dry atmosphere of the plains in the winter months. At the end of the rains, when the south-east monsoon has ceased to blow with constancy, views are obtained, sometimes from a distance of nearly two hundred miles. From the plains, the highest peaks subtend so small an angle, that they appear like white specks very low on the horizon, tipping the black lower and outer wooded ranges, which always rise out of a belt of haze, and from the density, probably, of the lower strata of atmosphere, are never seen to rest on the visible horizon. The remarkable lowness on the horizon of the whole stupendous mass is always a disappointing feature to the new comer, who expects to see dazzling peaks towering in the air. Approaching nearer, the snowy mountains sink behind the wooded ones, long before the latter have assumed gigantic proportions; and when they do so, they appear a sombre, lurid grey-green mass of vegetation, with no brightness or variation of colour. There is no break in this forest caused by rock, precipices, or cultivation; some spurs project nearer, and some valleys appear to retire further into the heart of the foremost great chain that shuts out all the country beyond.

From Dorjiling the appearance of parallel ridges is found to be deceptive, and due to the inosculating spurs of long tortuous ranges that ran north and south throughout the whole length of Sikkim, dividing deep wooded valleys, which form the beds of large rivers. The snowy peaks here look like a long east and west range of mountains, at an average distance of thirty or forty miles. Advancing into the country, this appearance proves equally deceptive, and the snowy range is resolved into isolated peaks, situated on the meridional ridges; their snow-clad spurs, projecting east and west, cross one another, and being uniformly white, appear to connect the peaks into one grand unbroken range. The rivers, instead of having their origin in the snowy mountains, rise far beyond them; many of their sources are upwards of one hundred miles in a straight line from the plains, in a very curious country, loftier by far in mean elevation than the meridional ridges which run south from it, yet comparatively bare of snow. This rearward part of the mountain region is Tibet, where all the Sikkim, Nepal, and Bhotan rivers rise as small streams, increasing in size as they receive the drainage from the snowed parts of the ridges that bound them in their courses. Their banks, between 8000 and 14,000 feet, are generally clothed with rhododendrons, sometimes to the almost total exclusion of other woody vegetation, especially near the snowy mountains—a cool temperature and great humidity being the most favourable conditions for the luxuriant growth of this genus.

The source of this humidity is the southerly or sea wind which blows steadily from May till October in Sikkim, and prevails throughout the rest of the year, if not as the monsoon properly so called, as a current from the moist atmosphere above the Gangetic delta. This rushes north to the rarefied regions of Sikkim, up the great valleys, and does not appear materially disturbed by the north-west wind, which blows during the afternoons of the winter months over the plains, and along the flanks of the outer range, and is a dry surface current, due to the diurnal heating of the soil. When it is considered that this wind, after passing lofty mountains on the outer range, has to traverse eighty or one hundred miles of alps before it has watered all the forest region, it will be evident that its moisture must be expended before it reaches Tibet.

Let the figures in the accompanying woodcut, the one on the true scale, the other with the heights exaggerated, represent two of these long meridional ridges, from the watershed to the plains of India, following in this instance the course of the Teesta river, from its source at 19,000 feet to where it debouches from the Himalaya at 300. The lower rugged outline represents one meridional ridge, with all its most prominent peaks (whether exactly or not on the line of section); the upper represents the parallel ridge of Singalelah (D.E.P.), of greater mean elevation, further west, introduced to show the maximum elevation of the Sikkim mountains, Kinchinjunga (28,178 feet), being represented on it. A deep valley is interposed between these two ridges, with a feeder of the Teesta in it (the Great Rungeet), which runs south from Kinchin, and turning west enters the Teesta at R. The position of the bed of the Teesta river is indicated by a dotted line from its source at T to the plains at S; of Dorjiling, on the north flank of the outer range, by _d_; of the first point where perpetual snow is met with, by P; and of the first indications of a Tibetan climate, by C.

A warm current of Air, loaded with vapour, will deposit the bulk of its moisture on the ridge of Sinchul, which rises above Dorjiling (_d_), and is 8,500 feet high. Passing on, little will be precipitated on _e_ whose elevation is the same as that of Sinchul; but much at _f_ (11,000 feet), where the current, being further cooled, has less capacity for holding vapour, and is further exhausted. When it ascends to P (15,000 feet) it is sufficiently cooled to deposit snow in the winter and spring months, more of which falling than can be melted during the summer, it becomes perennial. At the top of ginchin very little falls, and it is doubtful if the southerly current ever reaches that prodigiously elevated isolated summit. The amount of surface above 20,000 feet is, however, too limited and broken into isolated peaks to drain the already nearly, exhausted current, whose condensed vapours roll along in fog beyond the parallel of Kinchin, are dissipated during the day over the arid mountains of Tibet, and deposited at night on the cooled surface of the earth.

Section of the Sikkim Himalaya along the course of the Teesta River.

Other phenomena of no less importance than the distribution of vapour, and more or less depending on it, are the duration and amount of solar and terrestrial radiation. Towards D the sun is rarely seen during the rainy season, as well from the constant presence of nimbi aloft, as from fog on the surface of the ground. An absence of both light and heat is the result south of the parallel of Kinchin; and at C low fogs prevail at the same season, but do not intercept either the same amount of light or heat; whilst at T there is much sunshine and bright light. During the night, again, there is no terrestrial radiation between S and P; the rain either continues to pour—in some months with increased violence—or the saturated atmosphere is condensed into a thick white mist, which hangs over the redundant vegetation. A bright starlight night is almost unknown in the summer months at 6000 to 10,000 feet, but is frequent in December and January, and at intervals between October and May, when, however, vegetation is little affected by the cold of nocturnal radiation. In the regions north of Kinchin, starlight nights are more frequent, and the cold produced by radiation, at 14,000 feet, is often severe towards the end of the rains in September. Still the amount of clear weather during the night is small; the fog clears off for an hour or two at sunset as the wind falls, but the returning cold north current again chills the air soon afterwards, and rolling masses of vapour are hence flying overhead, or sweeping the surface of the earth, throughout the summer nights. In the Tibetan regions, on the other hand, bright nights and even sharp frosts prevail throughout the warmest months.

Referring again to the cut, it must be borne in mind that neither of the two meridional ridges runs in a straight line, but that they wind or zigzag as all mountain ranges do; that spurs from each ridge are given off from either flank alternately, and that the origin of a spur on one side answers to the source of a river (_i.e.,_ the head of a valley) on the other. These rivers are feeders of the main stream, the Teesta, and run at more or less of an angle to the latter. The spurs from the east flank of one ridge cross, at their ends, those from the west flank of another; and thus transverse valleys are formed, presenting many modifications of climate with regard to exposure, temperature, and humidity.

The roads from the plains of India to the watershed in Tibet always cross these lateral spurs. The main ridge is too winding and rugged, and too lofty for habitation throughout the greater part of its length, while the river-channel is always very winding, unhealthy for the greater part of the year below 4000 feet, and often narrow, gorge-like, and rocky. The villages are always placed above the unhealthy regions, on the lateral spurs, which the traveller repeatedly crosses throughout every day’s march; for these spurs give off lesser ones, and these again others of a third degree, whence the country is cut up into as many spurs, ridges, and ranges, as there are rills, streams, and rivers amongst the mountains.

Though the direction of the main atmospheric current is to the north, it is in reality seldom felt to be so, except the observer be on the very exposed mountain tops, or watch the motions of the upper strata of atmosphere. Lower currents of air rush up both the main and lateral valleys, throughout the day; and from the sinuosities in the beds of the rivers, and the generally transverse directions of their feeders, the current often becomes an east or west one. In the branch valleys draining to the north the wind still ascends; it is, in short, an ascending warm, moist current, whatever course be pursued by the valleys it follows.

The sides of each valley are hence equally supplied with moisture, though local circumstances render the soil on one or the other flank more or less humid and favourable to a luxuriant vegetation: such differences are a drier soil on the north side, with a too free exposure to the sun at low elevations, where its rays, however transient, rapidly dry the ground, and where the rains, though very heavy, are of shorter duration, and where, owing to the capacity of the heated air for retaining moisture, day fogs are comparatively rare. In the northern parts of Sikkim, again, some of the lateral valleys are so placed that the moist wind strikes the side facing the south, and keeps it very humid, whilst the returning cold current from the neighbouring Tibetan mountains impinges against the side facing the north, which is hence more bare of vegetation. An infinite number of local peculiarities will suggest themselves to any one conversant with physical geography, as causing unequal local distribution of light, heat, and moisture in the different valleys of so irregular a country; namely, the amount of slope, and its power of retaining moisture and soil; the composition and hardness of the rocks; their dip and strike; the protection of some valleys by lofty snowed ridges; and the free southern exposures of others at great elevations.

The position and elevation of the perpetual snow[401] vary with those of the individual ranges, and their exposure to the south wind. The expression that the perpetual snow lies lower and deeper on the southern slopes of the Himalayan mountains than on the northern, conveys a false impression. It is better to say that the snow lies deeper and lower on the southern faces of the individual mountains and spurs that form the snowy Himalaya. The axis itself of the chain is generally far north of the position of the spurs that catch all the snow, and has comparatively very little snow on it, most of what there is lying upon north exposures.

[401] It appears to me, as I have asserted in the pages of my Journal, that the limit of perpetual snow is laid down too low in all mountain regions, and that accumulations in hollows, and the descent of glacial ice, mask the phenomenon more effectually than is generally allowed. In this work I define the limit, as is customary, in general terms only, as being that where the accumulations are very great, and whence they are continuous upwards, on gentle slopes. All perpetual snow, however, becomes ice, and, as such, obeys the laws of glacial motion, moving as a viscous fluid; whence it follows that the lower edge of a snow-bed placed on a slope is, in one sense, the termination of a glacier, and indicates a position below that where all the snow that falls melts. I am well aware that it is impossible to define the limit required with any approach to accuracy. Steep and broken surfaces, with favourable exposures to the sun or moist winds, are bare much above places where snow lies throughout the year; but the occurrence of a gentle slope, free of snow, and covered with plants, cannot but indicate a point below that of perpetual snow. Such is the case with the “Jardin” on the Mer de Glace, whose elevation is 9,500 feet, whereas that of perpetual snow is considered by Professor J. Forbes, our best authority, to be 8,500 feet. Though limited in area, girdled by glaciers, presenting a very gentle slope to the east, and screened by surrounding mountains from a considerable proportion of the sun’s rays, the Jardin is clear, for fully three months of the year, of all but sporadic falls of snow, that never lie long; and so are similar spots placed higher on the neighbouring slopes; which facts are quite at variance with the supposition that the perpetual snow-line is below that point in the Mont Blanc Alps. On the Monte Rosa Alps, again, Dr. Thomson and I gathered plants in flower, above 12,000 feet on the steep face of the Weiss-thor Pass, and at 10,938 feet on the top of St. Theodule; but in the former case the rocks are too steep for any snow to lie, they are exposed to the south-east, and overhang a gorge 8000 feet deep, up which no doubt warm currents ascend; while at St. Theodule the plants were growing on a slope which, though gentle, is black and stony, and exposed to warm ascending currents, as on the Weiss-thor; and I do not consider either of these as evidences of the limit of perpetual snow being higher than their position.

A reference to the woodcut will show that the same circumstances which affect the distribution of moisture and vegetation, determine the position, amount, and duration of the snow. The principal fall will occur, as before shown, where the meridional range first attains a sufficiently great elevation, and the air becomes consequently cooled below 32°; this is at a little above 14,000 feet, sporadic falls occurring even in summer at that elevation: these, however, melt immediately, and the copious winter falls also are dissipated before June. As the depth of rain-fall diminishes in advancing north to the higher parts of the meridional ranges, so does that of the snow-fall. The permanence of the snow, again, depends on—1. The depth of the accumulation; 2. The mean temperature of the spot; 3. The melting power of the sun’s rays; 4. The prevalence and strength of evaporating winds. Now at 14,000 feet, though the accumulation is immense, the amount melted by the sun’s rays is trifling, and there are no evaporating winds; but the mean temperature is so high, and the corroding powers of the rain (which falls abundantly throughout summer) and of the warm and humid ascending currents are so great, that the snow is not perennial. At 15,500 feet, again, it becomes perennial, and its permanence at this low elevation (at P) is much favoured by the accumulation and detention of fogs over the rank vegetation which prevails from S nearly to P; and by the lofty mountains beyond it, which shield it from the returning dry currents from the north. In proceeding north all the circumstances that tend to the dispersion of the snow increase, whilst the fall diminishes. At P the deposition is enormous and the snow-line low—16,000 feet; whilst at T little falls, and the limit of perpetual snow is 19,000 and 20,000 feet. Hence the anomaly, that the snow-line ascends in advancing north to the coldest Himalayan regions. The position of the greatest peaks and of the greatest mass of perpetual snow being generally assumed as indicating a ridge and watershed, travellers, arguing from single mountains alone, on the meridional ridges, have at one time supported and at another denied the assertion, that the snow lies longer and deeper on the north than on the south slope of the Himalayan ridge.

The great accumulation of snow at 15,000 feet, in the parallel of P, exercises a decided influence on the vegetation. The alpine rhododendrons hardly reach 14,000 feet in the broad valleys and round-headed spurs of the mountains of the Tunkra and Chola passes; whilst the same species ascend to 16,000, and one to 17,000 feet, at T. Beyond the latter point, again, the great aridity of the climate prevents their growth, and in Tibet there are generally none even as low as 12,000 and 14,000 feet. Glaciers, again, descend to 15,000 feet in the tortuous gorges which immediately debouch from the snows of Kinchinjunga, but no plants grow on the débris they carry down, nor is there any sward of grass or herbage at their base, the atmosphere immediately around being chilled by enormous accumulations of snow, and the summer sun rarely warming the soil. At T, again, the glaciers do not descend below 16,000 feet, but a greensward of vegetation creeps up to their bases, dwarf rhododendrons cover the moraines, and herbs grow on the patches of earth carried down by the latter, which are thawed by the more frequent sunshine, and by the radiation of heat from the unsnowed flanks of the valleys down which these ice-streams pour.

Looking eastward or westward on the map of India, we perceive that the phenomenon of perpetual snow is regulated by the same laws. From the longitude of Upper Assam in 95° E to that of Kashmir in 75° E, the lowest limit of perpetual snow is 15,500 to 16,000 feet, and a shrubby vegetation affects the most humid localities near it, at 12,000 to 14,000 feet. Receding from the plains of India and penetrating the mountains, the climate becomes drier, the snowline rises, and vegetation diminishes, whether the elevation of the land increases or decreases; plants reaching 17,000 and 18,000 feet, and the snow-line, 20,000 feet. To mention extreme cases; the snow-level of Sikkim in 27° 30 minutes is at 16,000 feet, whereas in latitude 35° 30 minutes Dr. Thomson found the snow line 20,000 feet on the mountains near the Karakoram Pass, and vegetation up to 18,500 feet—features I found to be common also to Sikkim in latitude 28°.

The Himalaya, north of Nepal, and thence eastward to the bend of the Yaru-Tsampu (or Tibetan Burrampooter) has for its geographical limits the plains of India to the south, and the bed of the Yaru to the north. All between these limits is a mountain mass, to which Tibet (though so often erroneously called a plain)[402] forms no exception. The waters from the north side of this chain flow into the Tsampu, and those from the south side into the Burrampooter of Assam, and the Ganges. The line, however tortuous, dividing the heads of these waters, is the watershed, and the only guide we have to the axis of the Himalaya. This has never been crossed by Europeans, except by Captain Turner’s embassy in 1798, and Captain Bogle’s in 1779, both of which reached the Yaru river. In the account published by Captain Turner, the summit of the watershed is not rigorously defined, and the boundary, of Tibet and Bhotan is sometimes erroneously taken for it; the boundary being at that point a southern spur of Chumulari.[403] Eastwards from the sources of the Tsampu, the watershed of the Himalaya seems to follow a very winding course, and to be everywhere to the north of the snowy peaks seen from the plains of India. It is by a line through these snowy peaks that the axis of the Himalaya is represented in all our maps; because they _ seem_ from the plains to be situated on an east and west ridge, instead of being placed on subsidiary meridional ridges, as explained above. It is also across or along the subsidiary ridges that the boundary line between the Tibetan provinces and those of Nepal, Sikkim, and Bhotan, is usually drawn; because the enormous accumulations of snow form a more efficient natural barrier than the greater height of the less snowed central part of the chain beyond them.

[402] The only true account of the general features of eastern Tibet is to be found in MM. Huc and Gabet’s travels. Their description agrees with Dr. Thomson’s account of western Tibet, and with my experience of the parts to the north of Sikkim, and the information I everywhere obtained. The so-called _plains_ are the flat floors of the valleys, and the terraces on the margins of the rivers, which all flow between stupendous mountains. The term “maidan,” so often applied to Tibet by the natives, implies, not a plain like that of India, but simply an open, dry, treeless country, in contrast to the densely wooded wet regions of the snowy Himalaya, south of Tibet.

[403] Between Donkia and Chumulari lies a portion of Tibet (including the upper part of the course of the Machoo river) bounded on the east by Bhotan, and on the west by Sikkim (see chapter xxii). Turner, when crossing the Simonang Pass, descended westwards into the valley of the Machoo, and was still on the Indian watershed.

Though, however, our maps draw the axis through the snowy peaks, they also make the rivers to rise beyond the latter, on the northern slopes as it were, and to flow southwards through gaps in the axis. Such a feature is only reconcilable with the hypothesis of the chain being double, as the Cordillera of Peru and Chili is said to be, geographically, and which in a geological sense it no doubt is: but to the Cordillera the Himalaya offers no parallel. The results of Dr. Thomson’s study of the north-west Himalaya and Tibet, and my own of the north-east extreme of Sikkim and Tibet, first gave me an insight into the true structure of this chain. Donkia mountain is the culminant point of an immensely elevated mass of mountains, of greater mean height than a similarly extensive area around Kinchin junga. It comprises Chumulari, and many other mountains much above 20,000 feet, though none equalling Kinchinjunga, Junnoo, and Kubra. The great lakes of Ramchoo and Cholamoo are placed on it; and the rivers rising on it flow in various directions; the Painomchoo north-west into the Yaru; the Arun west to Nepal; the Teesta south-west through Sikkim; the Machoo south, and the Pachoo south-east, through Bhotan. All these rivers have their sources far beyond the great snowed mountains, the Arun most conspicuously of all, flowing completely at the back or north of Kinchinjunga. Those that flow southwards, break through no chain, nor do they meet any contraction as they pass the snowy parts of the mountains which bound the valleys in which they flow, but are bound by uniform ranges of lofty mountains, which become more snowy as they approach the plains of India. These valleys, however, gradually contract as they descend, being less open in Sikkim and Nepal than in Tibet, though there bounded by rugged mountains, which from being so bare of snow and of vegetation, do not give the same impression of height as the isolated sharper peaks which rise out of a dense forest, and on which the snow limit is 4000 or 5000 feet lower.

The fact of the bottom of the river valleys being flatter towards the watershed, is connected with that of their fall being less rapid at that part of their course; this is the consequence of the great extent in breadth of the most elevated portion of the chain. If we select the Teesta as an example, and measure its fall at three points of its course, we shall find the results very different. From its principal source at Lake Cholamoo, it descends from 17,000 to 15,000 feet, with a fall of 60 feet to the mile; from 15,000 to 12,000 feet, the fall is 140 feet to the mile; in the third part of its course it descends from 12,000 to 5000 feet, with a fall of 160 feet to the mile; and in the lower part the descent is from 5000 feet to the plains of India at 300 feet, giving a fall of 50 feet to the mile. There is, however, no marked limit to these divisions; its valley. gradually contracts, and its course gradually becomes more rapid. It is worthy of notice that the fall is at its maximum through that part of its valley of which the flanks are the most loaded with snow; where the old moraines are very conspicuous, and where the present accumulations from landslips, etc., are the most extensive.[404]

[404] It is not my intention to discuss here the geological bearings of this curious question; but I may state that as the humidity of the climate of the middle region of the river-course tends to increase the fall in a given space, so I believe the dryness of the climate of the loftier country has the opposite effect, by preserving those accumulations which have raised the floors of the valleys and rendered them level.

With reference to Kinchinjunga, these facts are of importance, as showing that mere elevation is in physical geography of secondary importance. That lofty mountain rises from a spur of the great range of Donkia, and is quite removed from the watershed or axis of the Himalaya, the rivers which drain its northern and southern flanks alike flowing to the Ganges. Were the Himalaya to be depressed 18,000 feet, Kubra, Junnoo, Pundim, etc., would form a small cluster of rocky islands 1000 to 7000 feet high, grouped near Kinchinjunga, itself a cape 10,000 feet high, which would be connected by a low, marrow neck, with an extensive and mountainous tract of land to its north-east; the latter being represented by Donkia. To the north of Kinchin a deep bay or inlet would occupy the present valley of the Arun, and would be bounded on the north by the axis of the Himalaya, which would form a continuous tract of land beyond it. Since writing the above, I have seen Professor J. Forbes’s beautiful work on the glaciers of Norway: it fully justifies a comparison of the Himalaya to Norway, which has long been a familiar subject of theoretical enquiry with Dr. Thomson and myself. The deep narrow valleys of Sikkim admirably represent the Norwegian fiords; the lofty, rugged, snowy mountains, those more or less submerged islands of the Norwegian coast; the broad rearward watershed, or axis of the chain, with its lakes, is the same in both, and the Yaru-tsampu occupies the relative position of the Baltic.

Along the whole chain of the Himalaya east of Kumaon there are, I have no doubt, a succession of such lofty masses as Donkia, giving off stupendous spurs such as that on which Kinchin forms so conspicuous a feature. In support of this view we find every river rising far beyond the snowy peaks, which are separated by continuously unsnowed ranges placed between the great white masses that these spurs present to the observer from the south.[405] From the Khasia mountains (south-east of Sikkim) many of these groups or spurs were seen by Dr. Thomson and myself, at various distances (80 to 210 miles); and these groups were between the courses of the great rivers the Soobansiri, Monass, and Pachoo, all east of Sikkim. Other masses seen from the Gangetic valley probably thus mark the relative positions of the Arun, Cosi, Gunduk, and Gogra rivers.

[405] At vol. i. p. 185, I have particularly called attention to the fact, that west of Kinchinjunga there is no continuation of a snowy Himalaya, as it is commonly called. So between Donkia and Chumulari there is no perpetual snow, and the valley of the Machoo is very broad, open, and comparatively flat.

Another mass like that of Chumulari and Donkia, is that around the Mansarowar lakes, so ably surveyed by the brothers Captains R. and H. Strachey, which is evidently the centre of the Himalaya. From it the Gogra, Sutlej, Indus, and Yaru rivers all flow to the Indian side of Asia; and from it spring four chains, two of which are better known than the others. These are:—1. The eastern Himalaya, whose axis runs north of Nepal, Sikkim, and Bhotan, to the bend of the Yaru, the valley of which it divides from the plains of India. 2. The north-west Himalaya, which separates the valley of the Indus from the plains of India. Behind these, and probably parallel to them, lie two other chains. 3. The Kouenlun or Karakoram chain, dividing the Indus from the Yarkand river. 4. The chain north of the Yaru, of which nothing is known. All the waters from the two first of these chains, flow into the Indian Ocean, as do those from the south faces of the third and fourth; those from the north side of the Kouenlun, and of the chain north of the Yaru, flow into the great valley of Lake Lhop, which may once have been continuous with the Amoor river.[406]

[406] The Chinese assert that Lake Lhop once drained into the Hoang-ho; the statement is curious, and capable of confirmation when central Asia shall have been explored.

For this view of the physical geography of the western Himalaya and central Asia, I am indebted to Dr. Thomson. It is more consonant with nature, and with what we know of the geography of the country and of the nature of mountain chains, than that of the illustrious Humboldt, who divides central Asia by four parallel chains, united by two meridional ones; one at each extremity of the mountain district. It follows in continuation and conclusion of our view that the mountain mass of Pamir or Bolor, between the sources of the Oxus and those of the Yarkand river, may be regarded as a centre from which spring the three greatest mountain systems of Asia. These are:—1. A great chain, which runs in a north-easterly direction as far as Behring’s Straits, separating all the rivers of Siberia from those which flow into the Pacific Ocean. 2. The Hindoo Koosh, continued through Persia, and Armenia into Taurus. And, 3. The Muztagh or Karakorum, which probably extends due east into China, south of the Hoang-ho, but which is broken up north of Mansarowar into the chains which have been already enumerated.

F.

ON THE CLIMATE OF SIKKIM.

The meteorology of Sikkim, as of every part of the Himalayan range, is a subject of growing interest and importance; as it becomes yearly more necessary for the Government to afford increased facilities for a residence in the mountains to Europeans in search of health, or of a salubrious climate for their families, or for themselves on retirement from the exhausting service of the plains. I was therefore surprised to find no further register of the weather at Dorjiling, than an insufficient one of the rain-fall, kept by the medical officer in charge of the station; who, in this, as in all similar cases,[407] has neither the time nor the opportunity to give even the minimum of required attention to the subject of meteorology. This defect has been in a measure remedied by Dr. Chapman, who kept a twelve-months’ register in 1837, with instruments carefully compared with Calcutta standards by the late James Prinsep, Esq., one of the most accomplished men in literature and science that India ever saw.

[407] The government of India has gone to an immense expense, and entailed a heavy duty upon its stationary medical officers, in supplying them with sometimes admirable, but more often very inaccurate, meteorological instruments, and requiring that daily registers be made, and transmitted to Calcutta. In no case have I found it to be in the officer’s power to carry out this object; he has never time, seldom the necessary knowledge and experience, and far too often no inclination. The majority of the observations are in most cases left to personal native or other servants, and the laborious results I have examined are too frequently worthless.

The annual means of temperature, rain-fall, etc., vary greatly in the Himalaya; and apparently slight local causes produce such great differences of temperature and humidity, that one year’s observations taken at one spot, however full and accurate they may be, are insufficient: this is remarkably the case in Sikkim, where the rainfall is great, and where the difference between those of two consecutive years is often greater than the whole annual London fall. My own meteorological observations necessarily form but a broken series, but they were made with the best instruments, and with a view to obtaining results that should be comparable _inter se,_ and with those of Calcutta; when away from Dorjiling too, in the interior of Sikkim, I had the advantage of Mr. Muller’s services in taking observations at hours agreed upon previous to my leaving, and these were of the greatest importance, both for calculating elevations, and for ascertaining the differences of temperature, humidity, diurnal atmospheric tide, and rain-fall; all of which vary with the elevation, and the distance from the plains of India.

Mr. Hodgson’s house proved a most favourable spot for an observatory, being placed on the top of the Dorjiling spur, with its broad verandah facing the north, in which I protected the instruments from radiation[408] and wind. Broad grass-plots and a gravel walk surrounded the house, and large trees were scattered about; on three sides the ground sloped away, while to the north the spur gently rose behind.

[408] This is a most important point, generally wholly neglected in India, where I have usually seen the thermometer hung in good shade, but exposed to reflected heat from walls, gravel walks, or dry earth. I am accustomed from experience to view all extreme temperatures with great suspicion, on this and other accounts. It is very seldom that the temperature of the free shaded air rises much above 100°, except during hot winds, when the lower stratum only of atmosphere (often loaded with hot particles of sand), sweeps over the surface of a soil scorched by the direct rays of the sun.

Throughout the greater part of the year the prevailing wind is from the south-east, and comes laden with moisture from the Bay of Bengal: it rises at sunrise, and its vapours are early condensed on the forests of Sinchul; billowy clouds rapidly succeed small patches of vapour, which rolling over to the north side of the mountain, are carried north-west, over a broad intervening valley, to Dorjiling. There they bank on the east side of the spur, and this being partially clear of wood, the accumulation is slow, and always first upon the clumps of trees. Very generally by 9 a.m., the whole eastern sky, from the top of Dorjiling ridge, is enveloped in a dense fog, while the whole western exposure enjoys sunshine for an hour or two later. At 7 or 8 a.m., very small patches are seen to collect on Tonglo, which gradually dilate and coalesce, but do not shroud the mountain for some hours, generally not before 11 a.m. or noon. Before that time, however, masses of mist have been rolling over Dorjiling ridge to the westward, and gradually filling up the valleys, so that by noon, or 1 p.m., every object is in cloud. Towards sunset it falls calm, when the mist rises, first from Sinchul, or if a south-east wind sets in, from Tonglo first.

The temperature is more uniform at Mr. Hodgson’s bungalow, which is on the top of the Dorjiling ridge, than on either of its flanks; this is very much because a good deal of wood is left upon it, whose cool foliage attracts and condenses the mists. Its mean temperature is lower by nearly 2·5° than that of Mr. Muller’s and Dr. Campbell’s houses, both situated on the slopes, 400 feet below. This I ascertained by numerous comparative observations of the temperature of the air, and by burying thermometers in the earth: it is chiefly to be accounted for by the more frequent sunshine at the lower stations, the power of the sun often raising the thermometer in shade to 80°, at Mr. Muller’s; whereas during the summer I spent at Mr. Hodgson’s it never rose much above 70°, attaining that height very seldom and for a very short period only. The nights, again, are uniformly and equally cloudy at both stations, so that there is no corresponding cold of nocturnal radiation to reduce the temperature.

The mean decrease of temperature due to elevation, I have stated (Appendix I.) to be about 1° for every 300 feet of ascent; according to which law Mr. Hodgson’s should not be more than 1·5° colder than Mr. Muller’s. These facts prove how difficult it is to choose unexceptionable sites for meteorological observatories in mountainous countries; discrepancies of so great an amount being due to local causes, which, as in this case, are perhaps transient; for should the top of the spur be wholly cleared of timber, its temperature would be materially raised; at the expense, probably, of a deficiency of water at certain seasons. Great inequalities of temperature are also produced by ascending currents of heated air from the Great Rungeet valley, which affect certain parts of the station only; and these raise the thermometer 10° (even when the sun is clouded) above what it indicates at other places of equal elevation.

The mean temperature of Dorjiling (elev. 7,430 feet) is very nearly 50°, or 2° higher than that of London, and 26° below that of Calcutta (78°,[409] or 78·5° in the latest published tables[410]); which, allowing 1° of diminution of temperature for every degree of latitude leaves 1° due to every 300 feet of ascent above Calcutta to the height of Dorjiling, agreeably to my own observations. This diminution is not the same for greater heights, as I shall have occasion to show in a separate chapter of this Appendix, on the decrement of heat with elevation.

[409] Prinsep, in As. Soc. Journ., Jan. 1832, p. 30.

[410] Daniell’s Met. Essays, vol. ii. p. 341.

A remarkable uniformity of temperature prevails throughout the year at Dorjiling, there being only 22° difference between the mean temperatures of the hottest and coldest months; whilst in London, with a lower mean temperature, the equivalent difference is 27°. At 11,000 feet this difference is equal to that of London. In more elevated regions, it is still greater, the climate becoming excessive at 15,000 feet, where the difference amounts to 30° at least.[411] The accompanying table is the result of an attempt to approximate to the mean temperatures and ranges of the thermometer at various elevations.

[411] This is contrary to the conclusions of all meteorologists who have studied the climate of the Alps, and is entirely due to the local disturbances which I have so often dwelt upon, and principally to the unequal distribution of moisture in the loftier rearward regions, and the aridity of Tibet. Professor James Forbes states (Ed. Phil. Trans., v. xiv. p. 489):—1. That the decrement of temperature with altitude is most rapid in summer: this (as I shall hereafter show) is not the case in the Himalaya, chiefly because the warm south moist wind then prevails. 2. That the annual range of temperature diminishes with the elevation: this, too, is not the case in Sikkim, because of the barer surface and more cloudless skies of the rearward loftier regions. 3. That the diurnal range of temperature diminishes with the height: that this is not the cane follows from the same cause. 4. That radiation is least in winter: this is negatived by the influence of the summer rains.

Altitude Mean Shade Mean Warmest Month Mean Coldest Month Mean Daily Range of Temperature Rain-fall in inches 11,000 feet 15,000 feet 19,000 feet 40·9 29·8 19·8 50·0 40·0 32·0 24·0 11·0 0·0 20·0 27·0 35·0 40·0 20·0 10·0 1°=320 feet 1°=350 feet 1°=400 feet

Supposing the same formula to apply (which I exceedingly doubt) to heights above 19,000 feet, 2° would be the mean annual temperature of the summit of Kinchinjunga, altitude 28,178 feet, the loftiest known spot on the globe: this is a degree or two higher than the temperature of the poles of greatest cold on the earth’s surface, and about the temperature of Spitzbergen and Melville island.

The upper limit of phenogamic vegetation coincides with a mean temperature of 30° on the south flank of Kinchinjunga, and of 22° in Tibet; in both cases annuals and perennial-rooted herbaceous plants are to be found at elevations corresponding to these mean temperatures, and often at higher elevations in sheltered localities. I have assumed the decrease of temperature for a corresponding amount of elevation to be gradually less in ascending (1°=320 feet at 6000 to 10,000 feet, 1°=400 feet at 14,000 to 18,000 feet). My observations appear to prove this, but I do not regard them as conclusive; supposing them to be so, I attribute it to a combination of various causes, especially to the increased elevation and yet unsnowed condition of the mass of land elevated above 16,000 feet, and consequent radiation of heat; also to the greater amount of sunshine there; and to the less dense mists which obstruct the sun’s rays at all elevations. In corroboration of this I may mention that the decrease of temperature with elevation is much less in summer than in winter, 1° of Fahr. being equivalent to only 250 feet in January between 7000 and 13,000 feet, and to upwards of 400 feet in July. Again, at Dorjiling (7,430 feet) the temperature hardly ever rises above 70° in the summer months, yet it often rises even higher in Tibet at 12,000 to 14,000 feet. On the other hand, the winters, and the winter nights especially, are disproportionately cold at great heights, the thermometer falling upwards of 40° below the Dorjiling temperature at an elevation only 6000 feet higher.

The diurnal distribution of temperature is equally and similarly affected by the presence of vapour at different altitudes. The lower and outer ranges of 6000 to 10,000 feet, first receive the diurnal charge of vapour-loaded southerly winds; those beyond them get more of the sun’s rays, and the rearward ones more still. Though the summer days of the northern localities are warmer than their elevation would indicate, the nights are not proportionally cold; for the light mist of 14,000 feet, which replaces the dense fog of 7000 feet, effectually obstructs nocturnal radiation, though it is less an obstacle to solar radiation. Clear nights, be it observed, are as rare at Momay (15,300 feet) as at Dorjiling, the nights if windy being rainy; or, if calm, cold currents descend from the mountains, condensing the moist vapours of the valleys, whose narrow floors are at sunrise bathed in mist at all elevations in Sikkim. The rise and dispersion of these dense mists, and their collection and recondensation on the mountains in the morning, is one of the most magnificent phenomena of the Himalaya, when viewed from a proper elevation; it commences as soon as the sun appears on the horizon.

The mean daily range of the thermometer at 7000 feet is 13° in cleared spots, but considerably less in wooded, and certainly one-third less in the forest itself. At Calcutta, which has almost an insular climate, it amounts to 17°; at Delhi, which has a continental one, to 24·6°; and in London to 17·5°. At 11,000 feet it amounts to about 20°, and at 15,000 feet to 27°. These values vary widely in the different months, being much less in the summer or rainy months. The following is probably a fair approximation:—

At 7,000 feet it amounts to 8–9° in Aug. and Sept., and 17° in Dec. At 11,000 feet it amounts to 12° in Aug. and Sept., and 30° in Dec. At 15,000 feet it amounts to 15° in Aug. and Sept., and 40° in Dec. At London it amounts to 20° in Aug. and Sept., and 10° in Dec.

The distribution of temperature throughout the day and year varies less at Dorjiling than in most mountainous countries, owing to the prevailing moisture, the effect of which is analogous to that of a circumambient ocean to an island: the difference being, that in the case of the island the bulk of water maintains an uniform temperature; in that of Dorjiling the quantity of vapour acts directly by interfering with terrestrial and solar-radiation, and indirectly by nurturing a luxuriant vegetation. The result in the latter case is a climate remarkable for its equability, and similar in many features to that of New Zealand, South-west Chili, Fuegia, and the damp west coasts of Scotland and Ireland, and other countries exposed to moist sea winds.

The mean temperature of the year at Dorjiling, as taken by maxima and minima thermometers[412] by Dr. Chapman, is nearly the same as that of March and October: January, the coldest month, is more than 13·4° colder than the mean of the year; but the hottest month is only 8·3° warmer than the same mean: at Calcutta the months vary less from the mean; at Delhi more; and in London the distribution is wholly different; there being no rains to modify the summer heat, July is 13° hotter, and January 14° colder than the mean of the year.

[412] The mean of several of the months, thus deduced, often varies a good deal from the truth, owing to the unequal diurnal distribution of heat; a very few minutes’ sunshine raises the temperature l0° or 15° above the mean of the day; which excessive heat (usually transient) the maximum thermometer registers, and consequently gives too high a mean.

This distribution of the seasons has a most important effect upon vegetation, to which sufficient attention has not been paid by cultivators of alpine Indian plants; in the first place, though English winters are cold enough for such, the summers are too hot and dry; and, in the second place, the great accession of temperature, causing the buds to burst in spring, occurs in the Himalaya in March, when the temperature at 7000 feet rises 8° above that of February, raising the radiating thermometer always above the freezing point, whence the young leaves are never injured by night frost: in England the corresponding rise is only 3°, and there is no such accession of temperature till May, which is 8° warmer than April; hence, the young foliage of many Himalayan plants is cut off by night frosts in English gardens early in the season, of which _Abies Webbiana_ is a conspicuous example.

The greatest heat of the day occurs at Dorjiling about noon, owing to the prevalent cloud, especially during the rainy months, when the sun shines only in the mornings, if at all, and the clouds accumulate as the day advances. According to hourly observations of my own, it occurred in July at noon, in August at 1 p.m., and in September (the most rainy month) there was only four-tenths of a degree difference between the means of noon, 1 p.m., and 2 p.m., but I must refer to the abstracts at the end of this chapter for evidence of this, and of the wonderful uniformity of temperature during the rainy months. In the drier season again, after September, the greatest heat occurs between 2 and 3 p.m.; in Calcutta the hottest hour is about 2.45 p.m., throughout the year; and in England also about 3 p.m.

The hour whose temperature coincides with the mean of the day necessarily varies with the distribution of cloud and sunshine; it is usually about 7 a.m. and 7 p.m.; whereas in Calcutta the same coincidence occurs at a little before 10 a.m., and in England at about 8 a.m.

Next to the temperature of the air, observations on that of the earth are perhaps of the greatest value; both from their application to horticulture, and from the approximation they afford to the mean temperature of the week or month in which they are taken. These form the subject of a separate chapter.

Nocturnal and solar radiation, the one causing the formation of dew and hoar-frost when the air in the shade is above freezing, end killing plants by the rapid abstraction of heat from all their surfaces which are exposed to the clear sky, and the other scorching the skin and tender plants during the day, are now familiar phenomena, and particularly engaged my attention during my whole Indian journey. Two phenomena particularly obstruct radiation in Sikkim—the clouds and fog from the end of May till October, and the haze from February till May. Two months alone are usually clear; one before and one after the rains, when the air, though still humid, is transparent. The haze has never been fully explained, though a well-known phenomenon. On the plains of India, at the foot of the hills, it begins generally in the forenoon of the cold season, with the rise of the west wind; and, in February especially, obscures the sun’s disc by noon; frequently it lasts throughout the twenty-four hours, and is usually accompanied by great dryness of the atmosphere. It gradually diminishes in ascending, and have never experienced it at 10,000 feet; at 7000, however, it very often, in April, obscures the snowy ranges 30 miles off, which are bright and defined at sunrise, and either pale away, or become of a lurid yellow-red, according to the density of this haze, till they disappear at 10 a.m. I believe it always accompanies a south-west wind (which is a deflected current of the north-west) and dry atmosphere in Sikkim.

The observations for solar radiation were taken with a black-bulb thermometer, and also with actinometers, but the value of the data afforded by the latter not being fixed or comparative, I shall give the results in a separate section. (See Appendix K.) From a multitude of desultory observations, I conclude that at 7,400 feet, 125·7°, or +67° above the temperature of the air, is the average maximum effect of the sun’s rays on a black-bulb thermometer[413] throughout the year, amounting rarely to +70° and +80° in the summer months, but more frequently in the winter or spring. These results, though greatly above what are obtained at Calcutta, are not much, if at all, above what may be observed on the plains of India. This effect is much increased with the elevation. At 10,000 feet in December, at 9 a.m., I saw the mercury mount to 132° with a difl: of +94°, whilst the temperature of shaded snow hard by was 22°; at 13,100 feet, in January, at 9 a.m., it has stood at 98°, diff. +68·2°; and at 10 a.m., at 114°, diff. +81·4°, whilst the radiating thermometer on the snow had fallen at sunrise to 0·7°. In December, at 13,500 feet, I have seen it 110°, diff. +84°; at 11 a.m., 11,500 feet; 122°, diff: +82°. This is but a small selection from many instances of the extraordinary power of solar radiation in the coldest months, at great elevations.

[413] From the mean of very many observations, I find that 10° is the average difference at the level of the sea, in India, between two similar thermometers, with spherical bulbs (half-inch diam.), the one of black, and the other of plain glass, and both being equally exposed to the sun’s rays.

Nocturnal and terrestrial radiation are even more difficult phenomena for the traveller to estimate than solar radiation, the danger of exposing instruments at night being always great in wild countries. I most frequently used a thermometer graduated on the glass, and placed in the focus of a parabolic reflector, and a similar one laid upon white cotton,[414] and found no material difference in the mean of many observations of each, though often 1° to 2° in individual ones. Avoiding radiation from surrounding objects is very difficult, especially in wooded countries. I have also tried the radiating power of grass and the earth; the temperature of the latter is generally less, and that of the former greater, than the thermometer exposed on cotton or in the reflector, but much depends on the surface of the herbage and soil.

[414] Snow radiates the most powerfully of any substance I have tried; in one instance, at 13,000 feet, in January, the thermometer on snow fell to 0·2°, which was 10·8° below the temperature at the time, the grass showing 6·7°; and on another occasion to 1·2°, when the air at the time (before sunrise) was 21·2°; the difference therefore being 20°. I have frequently made this observation, and always with a similar result; it may account for the great injury plants sustain from a thin covering of ice on their foliage, even when the temperature is but little below the freezing-point.

The power of terrestrial, like that of solar radiation, increases with the elevation, but not in an equal proportion. At 7,400 feet, the mean of all my observations shows a temperature of 35·4°. During the rains, 3° to 4° is the mean maximum, but the nights being almost invariably cloudy, it is scarcely on one night out of six that there is any radiation. From October to December the amount is greater=10° to 12, and from January till May greater still, being as much as 15°. During the winter months the effect of radiation is often felt throughout the clear days, dew forming abundantly at 4000 to 8000 feet in the shaded bottoms of narrow valleys, into which the sun does not penetrate till 10 a.m., and from which it disappears at 3 p.m. I have seen the thermometer in the reflector fall 12° at 10 a.m. in a shaded valley. This often produces an anomalous effect, causing the temperature in the shade to fall after sunrise; for the mists which condense in the bottom of the valleys after midnight disperse after sunrise, but long before reached by the sun, and powerful radiation ensues, lowering the surrounding temperature: a fall of 1° to 2° after sunrise of air in the shade is hence common in valleys in November and December.[415] The excessive radiation of the winter months often gives rise to a curious phenomenon; it causes the formation of copious dew on the blanket of the traveller’s bed, which radiates heat to the tent roof, and this inside either an open or a closed tent. I have experienced this at various elevations, from 6000 to 16,000 feet. Whether the minimum temperature be as high as 50°, or but little above zero, the effect is the same, except that hoar-frost or ice forms in the latter case. Another remarkable effect of nocturnal radiation is the curl of the alpine rhododendron leaves in November, which is probably due to the freezing and consequent expansion of the water in the upper strata of cells exposed to the sky. The first curl is generally repaired by the ensuing day’s sun, but after two or three nights the leaves become permanently curled, and remain so till they fall in the following spring.

[415] Such is the explanation which I have offered of this phenomenon in the Hort. Soc. Journal. On thinking over the matter since, I have speculated upon the probability of this fall of temperature being due to the absorption of heat that must become latent on the dispersion of the dense masses of white fog that choke the valleys at sunrise.

I have said that the nocturnal radiation in the English spring months is the great obstacle to the cultivation of many Himalayan plants; but it is not therefore to be inferred that there is no similar amount of radiation in the Himalaya; for, on the contrary, in April its amount is much greater than in England, frequently equalling 13° of difference; and I have seen 16° at 7,500 feet; but the minimum temperature at the time is 51°, and the absolute amount of cold therefore immaterial. The mean minimum of London is 38°, and, when lowered 5·5° by radiation, the consequent cold is very considerable. Mr. Daniell, in his admirable essay on the climate of London, mentions 17° as the maximum effect of nocturnal radiation ever observed by him. I have registered 16° in April at Dorjiling; nearly as much at 6000 feet in February; twice 13°, and once 14·2° in September at 15,500 feet; and 10° in October at 16,800 feet; nearly 13° in January at 7000 feet; 14·5° in February at that elevation, and, on several occasions, 14·7° at 10,000 feet in November.

The annual rain-fall at Dorjiling averages 120 inches (or 10 feet), but varies from 100 to 130 in different years; this is fully three times the amount of the average English fall,[416] and yet not one-fourth of what is experienced on the Khasia hills in Eastern Bengal, where fifty feet of rain falls. The greater proportion descends between June and September, as much as thirty inches sometimes falling in one month. From November to February inclusive, the months are comparatively dry; March and October are characterised by violent storms at the equinoxes, with thunder, destructive lightning, and hail.

[416] The general ideas on the subject of the English rain-fall are so very vague, that I may be pardoned for reminding my readers that in 1852, the year of extraordinary rain, the amounts varied from 28·5 inches in Essex, to 50 inches at Cirencester, and 67·5 (average of five years) at Plympton St. Mary’s, and 102·5 at Holme, on the Dart.

The rain-gauge takes no account of the enormous deposition from mists and fogs: these keep the atmosphere in a state of moisture, the amount of which I have estimated at 0·88 as the saturation-point at Dorjiling, 0·83 being that of London. In July, the dampest month, the saturation-point is 0·97; and in December, owing to the dryness of the air on the neighbouring plains of India, whence dry blasts pass over Sikkim, the mean saturation-point of the month sometimes falls as low as 0·69.

The dew-point is on the average of the year 49·3°, or 3° below the mean temperature of the air. In the dampest month (July) the mean dew-point is only eight-tenths of a degree below the temperature, whilst in December it sinks 10° below it. In London the dew-point is on the average 5·6° below the temperature; none of the English months are so wet as those of Sikkim, but none are so dry as the Sikkim December sometimes is.

_On the weight of the atmosphere in Sikkim; and its effects on the human frame._

Of all the phenomena of climate, the weight of the atmosphere is the most remarkable for its elusion of direct observation, when unaided by instruments. At the level of the sea, a man of ordinary bulk and stature is pressed upon by a superincumbent weight of 30,000 pounds or 13·5 tons. An inch fall or rise in the barometer shows that this load is lightened or increased, sometimes in a few hours, by nearly 1,000 pounds; and no notice is taken of it, except by the meteorologist, or by the speculative physician, seeking the subtle causes of epidemic and endemic complaints. At Dorjiling (7,400 feet), this load is reduced to less than 2,500 pounds, with no appreciable result whatever on the frame, however suddenly it be transported to that elevation. And the observation of my own habits convinced me that I took the same amount of meat, drink, sleep, exercise and work, not only without inconvenience, but without the slightest perception of my altered circumstances. On ascending to 14,000 feet, owing to the diminished supply of oxygen, exercise brings on vertigo and headache; ascending higher still, lassitude and tension across the forehead ensue, with retching, and a sense of weight dragging down the stomach, probably due to dilatation of the air contained in that organ. Such are the all but invariable effects of high elevations; varying with most persons according to the suddenness and steepness of the ascent, the amount and duration of exertion, and the length of time previously passed at great heights. After having lived for some weeks at 15,300 feet, I have thence ascended several times to 18,500, and once above 19,000 feet, without any sensations but lassitude and quickness of pulse;[417] but in these instances it required great caution to avoid painful symptoms. Residing at 15,300 feet, however, my functions were wholly undisturbed; nor could I detect any quickness of pulse or of respiration when the body was at rest, below 17,000 feet. At that elevation, after resting a party of eight men for an hour, the average of their and my pulses was above 100°, both before and after eating; in one case it was 120°, in none below 80°.

[417] I have in a note to vol. ii. p. 160, stated that I never experienced in my own person, nor saw in others, bleeding at the ears, nose, lips, or eyelids.

Not only is the frame of a transient visitor unaffected (when at rest) by the pressure being reduced from 30,000 to 13,000 pounds, but the Tibetan, born and constantly residing at upwards of 14,000 feet, differs in no respect that can be attributed to diminished pressure, from the native of the level of the sea. The averaged duration of life, and the amount of food and exercise is the same; eighty years are rarely reached by either. The Tibetan too, however inured to cold and great elevations, still suffers when he crosses passes 18,000 or 19,000 feet high, and apparently neither more nor less than I did.

Liebig remarks (in his “Animal Chemistry”) that in an equal number of respirations,[418] we consume a larger amount of oxygen at the level of the sea than on a mountain; and it can be shown that under ordinary circumstances at Dorjiling, 20·14 per cent. less is inhaled than on the plains of India. Yet the chest cannot expand so as to inspire more at once, nor is the respiration appreciably quickened; by either of which means nature would be enabled to make up the deficiency. It is true that it is difficult to count one’s own respirations, but the average is considered in a healthy man to be eighteen in a minute; in my own case it is sixteen, an acceleration of which by three or four could not have been overlooked, in the repeated trials I made at Dorjiling, and still less the eight additional inhalations required at 15,000 feet to make up for the deficiency of oxygen in the air of that elevation.

[418] For the following note I am indebted to my friend, C. Muller, Esq., of Patna.— According to Sir H. Davy, a man consumes 45,504 cubic inches of oxygen in twenty-four hours, necessitating the inspiration of 147,520 cubic inches of atmospheric air.—At pressure 23 inches, and temp. 60° this volume of atmospheric air (dry) would weigh 35,138·75 grains.—At pressure 30 in., temp. 80°, it would weigh 43,997·63 gr. The amount of oxygen in atmospheric air is 23·32 per cent. by weight. The oxygen, then, in 147,520 cubic inches of dry air, at pressure 23 in., temp. 80°, weighs 8,194·35 gr.; and at pressure 30 in., temp. 80°, it weighs 10,260·25 gr. Hence the absolute quantity of oxygen in a given volume of atmospheric air, when the pressure is 23 in., and the temp. 60°, is 20·14 per cent. less than when the pressure is 30 in. and the temp. 80°. When the air at pressure 23 in:, temp. 60°, is saturated with moisture, the proportion of dry air and aqueous vapour in 100 cubic inches is as follows:— Dry air 97·173 Vapour 2·827 At pressure 30 in., temp. 80°, the proportions are:— Dry air 96·133 Vapour 3·867 The effect of aqueous vapour in the air on the amount of oxygen available for consumption, is very trifling; and it must not be forgotten that aqueous vapour supplies oxygen to the system as well as atmospheric air.

It has long been surmised that an alpine vegetation may owe some of its peculiarities to the diminished atmospheric pressure; and that the latter being a condition which the gardener cannot supply, he can never successfully cultivate such plants in general. I know of no foundation for this hypothesis; many plants, natives of the level of the sea in other parts of the world, and some even of the hot plains of Bengal, ascend to 12,000 and even 15,000 feet on the Himalaya, unaffected by the diminished pressure. Any number of species from low countries may be cultivated, and some have been for ages, at 10,000 to 14,000 feet without change. It is the same with the lower animals; innumerable instances may with ease be adduced of pressure alone inducing no appreciable change, whilst there is absence of proof to the contrary. The phenomena that accompany diminished pressure are the real obstacles to the cultivation of alpine plants, of which cold and the excessive climate are perhaps the most formidable. Plants that grow in localities marked by sudden extremes of heat and cold, are always very variable in stature, habit, and foliage. In a state of nature we say the plants “accommodate themselves” to these changes, and so they do within certain limits; but for one that survives of all the seeds that germinate in these inhospitable localities, thousands die. In our gardens we can neither imitate the conditions of an alpine climate, nor offer others suited to the plants of such climates.

The mean height of the barometer at Mr. Hodgson’s was 23·010, but varied 0·161 between July, when it was lowest, and October, when it was highest; following the monthly rise and fall of Calcutta as to period, but not as to amount (or amplitude); for the mercury at Calcutta stands in July upwards of half an inch (0·555 Prinsep) lower than it does in December.

The diurnal tide of atmosphere is as constant as to the time of its ebb and flow at Dorjiling as at Calcutta; and a number of very careful observations (made with special reference to this object) between the level of the plains of India, and 17,000 feet, would indicate that there is no very material deviation from this at any elevation in Sikkim. These times are very nearly 9.50 a.m. and about 10 p.m. for the maxima, the 9.50 a.m. very constantly, and the 10 p.m. with more uncertainty; and 4 a.m. and 4 p.m. for the minima, the afternoon ebb being most true to its time, except during the rains.

At 9.50 a.m. the barometer is at its highest, and falls till 4 p.m., when it stands on the average of the year 0·074 of an inch lower; during the same period the Calcutta fall is upwards of one-tenth of an inch (0·121 Prinsep).

It has been proved that at considerable elevations in Europe, the hours of periodic ebb and flow differ materially from those which prevail at the level of the sea; but this is certainly not the case in the Sikkim Himalaya.

The amplitude decreases in amount from 0·100 at the foot of the hills, to 0·074 at 7000 feet; and the mean of 132 selected unexceptionable observations, taken at nine stations between 8000 and 15,500 feet, at 9.50 a.m. and 4 p.m., gives an average fall of 0·056 of an inch; a result which is confirmed by interpolation from numerous horary observations at these and many other elevations, where I could observe at the critical hours.

That the Calcutta amplitude is not exceptionally great, is shewn by the register kept at different places in the Gangetic valley and plains of India, between Saharunpore and the Bay of Bengal. I have seen apparently trustworthy records of seven[419] such, and find that in all it amounts to between 0·084 and 0·120 inch, the mean of the whole being 0·101 of an inch.

[419] Calcutta, Berampore, Benares, Nagpore, Moozufferpore, Delhi, and Saharunpore.

The amplitude is greatest (0·088) in the spring months (March, April, and May), both at Dorjiling and Calcutta: it is least at both in June and July, (0·027 at Dorjiling), and rises again in autumn (to ·082 in September).

The horary oscillations also are as remarkably uniform at all elevations, as the period of ebb and flow: the mercury falls slowly from 9.50 a.m. (when it is at its highest) till noon, then rapidly till 3 p.m., and slowly again till 4 p.m.; after which there is little change until sunset; it rises rapidly between 7 and 9 p.m., and a little more till 10 p.m.; thence till 4 a.m. the fall is inconsiderable, and the great rise occurs between 7 and 9 a.m.

It is well known that these fluctuations of the barometer are due to the expansion and contraction by heat and moisture of the column of atmosphere that presses on the mercury, in the cistern of the instrument: were the air dry, the effect would be a single rise and fall;[420] the barometer would stand highest at the hottest of the twenty-four hours, and lowest at the coldest; and such is the case in arid continental regions which are perennially dry. That such would also be the case at Calcutta and throughout the Himalaya of Sikkim, is theoretically self-evident, and proved by my horary observations taken during the rainy months of 1848. An inspection of these at the end of this section (where a column contains the pressure of dry air) shows but one maximum of pressure, which occurs at the coldest time of the twenty-four hours (early in the morning), and one minimum in the afternoon. In the table of mean temperatures of the months, also appended to this section, will also be found a column allowing the pressure of dry air, whence it will be seen that there is but one maximum of the pressure of dry air, occurring at the coldest season in December, and one minimum, in July. The effect of the vapour is the same on the annual as upon the diurnal march of the pressure, producing a double maximum and minimum in the year in one case, and in the twenty-four hours in the other.

[420] This law, for which we are indebted to Professor Dove, has been clearly explained by Colonel Sabine in the appendix to his translation of Humboldt’s “Cosmos,” vol. i. p. 457.

I append a meteorological register of the separate months, but at the same time must remind the reader that it does not pretend to strict accuracy. It is founded upon observations made at Dorjiling by Dr. Chapman in the year 1837, for pressure temperature and wet-bulb only; the other data and some modifications of the above are supplied from observations of my own. Those for terrestrial and nocturnal radiation are accurate as far as they go, that is to say, they are absolute temperatures taken by myself, which may, I believe, be recorded in any year, but much higher are no doubt often to be obtained. The dew-points and saturations are generally calculated from the mean of two day observations (10 a.m. and 4 p.m.) of the wet-bulb thermometer, together with the minimum, or are taken from observations of Daniell’s hygrometer; and as I find the mean of the temperature of 10 a.m., 4 p.m., and the minimum, to coincide within a few tenths with the mean temperature of the whole day, I assume that the mean of the wet-bulb observations of the same hours will give a near approach to that of the twenty-four hours. The climate of Dorjiling station has been in some degree altered by extensive clearances of forest, which render it more variable, more exposed to night frosts and strong sun-heat, and to drought, the drying up of small streams being one direct consequence. My own observations were taken at Mr. Hodgson’s house, elevated 7,430 feet, the position of which I have indicated at the commencement of this section, where the differences of climate due to local causes are sufficiently indicated to show that in no two spots could similar meteorological results be obtained. At Mr. Hodgson’s, for instance, the uniformity of temperature and humidity is infinitely more remarkable than at Dr. Chapman’s, possibly from my guarding more effectually against radiation, and from the greater forests about Mr. Hodgson’s house. I have not, however, ventured to interfere with the temperature columns on this account.

DORJILING METEOROLOGICAL REGISTER.

Jan. Feb. Mar. Apr. May June Pressure of Atmosphere[421] Range of Pressure Mean Shade Maximum Shade Maximum Sun Greatest Difference Mean Maximum Shade Minimum Shade Minimum Radiation Greatest Difference Mean Minimum Shade Mean Daily Range of Temps Sunk Thermometer Mean Dew-point Mean Dryness Force of Vapour Pressure of Dry Air Mean Saturation Rain in inches 23·307 ·072 40·0 56·0 119·0 72·0 47·2 29·0 16·0 12·7 32·8 14·4 46·0 34·3 5·1 ·216 23·091 ·84 1·72 23·305 ·061 42·1 57·0 124·0 78·0 50·0 25·5 23·0 15·3 34·2 15·8 48·0 37·2 3·9 ·239 23·066 ·87 0·92 23·307 ·083 50·7 66·5 120·0 60·0 58·4 37·0 27·8 8·7 43·1 15·3 50·0 45·8 5·8 ·323 23·084 ·82 1·12 23·280 ·085 55·9 68·5 125·0 66·0 63·7 38·0 33·0 16·0 48·1 15·6 58·0 49·8 6·6 ·371 22·909 ·80 2·52 23·259 ·088 57·6 69·0 125·0 65·0 65·3 38·0 40·0 10·0 50·0 15·3 61·0 54·4 2·7 ·434 22·825 ·91 9·25 23·207 ·067 61·2 71·0 126·2 62·2 66·7 51·5 47·0 4·8 55·8 10·9 62·0 59·5 2·0 ·515 22·692 ·93 26·96

July Aug. Sept. Oct. Nov. Dec. Mean Pressure of Atmosphere[421] Range of Pressure Mean Shade Maximum Shade Maximum Sun Greatest Difference Mean Maximum Shade Minimum Shade Minimum Radiation Greatest Difference Mean Minimum Shade Mean Daily Range of Temps Sunk Thermometer Mean Dew-point Mean Dryness Force of Vapour Pressure of Dry Air Mean Saturation

Rain in inches 23·203 ·062 61·4 69·5 130·0 62·0 65·5 56·0 52·0 3·5 57·3 8·2 62·2 60·7 0·8 ·535 22·668 ·97

25·34 23·230 ·070 61·7 70·0 133·0 62·0 66·1 54·5 50·0 3·5 57·4 8·7 62·0 60·4 1·1 ·530 22·700 ·96

29·45 23·300 ·082 59·9 70·0 142·0 70·0 64·7 51·5 47·5 10·0 55·2 9·5 61·0 58·5 1·4 ·498 22·802 ·95

15·76 23·372 ·075 58·0 68·0 133·0 65·0 66·5 43·5 32·0 12·0 49·5 17·0 60·0 52·5 4·2 ·407 22·865 ·86

8·66 23·330 ·078 50·0 63·0 123·0 68·0 56·5 38·0 30·0 12·0 43·5 13·0 55·0 46·5 3·2 ·331 22·999 ·90

0·11 23·365 ·062 43·0 56·0 108·0 77·2 51·6 32·5 26·0 10·0 34·9 16·7 49·0 31·8 10·6 ·198 23·165 ·69

0·45 22·289 ·074 53·5 65·4 125·7 67·3 60·2 41·3 35·4 9·9 46·8 13·4 56·2 49·4 4·0 ·383 22·906 ·88 Sum 122·26

[421] These are taken from Dr. Chapman’s Table; and present a greater annual range (=0·169) than my observations in 1848–9, taken at Mr. Hodgson’s which is higher than Dr. Chapman’s; or than Mr. Muller’s, which is a little lower, and very near it.

_Horary Observations at Jillapahar, Dorjiling, Alt. 7,430 feet._

JULY, 1848

No. of Obser- vations Hour Baro- meter corrected Temp. Air Dew Point Diff. Tension of Vapour Weight of Vapour Humi- dity Pressure of Dry Air 7 23 27 22 20 26 12 11 25 23 13 10 6 6 22 6 6 19 1 a.m. 8 9 10 11 Noon 1 p.m. 2 3 4 5 6 7 8 9 10 11 Midnight 22·877 ·882 ·884 +·899 ·899 ·884 ·876 ·866 ·852 ·846 –·840 ·845 ·853 ·867 ·878 ·885 +·887 ·887 59·6 62·1 62·6 63·5 64·1 65·0 64·1 64·4 64·8 64·1 64·7 63·7 62·7 61·0 60·7 60·5 60·2 59·8 58·9 60·6 61·3 61·7 62·3 63·1 61·7 61·0 62·6 61·7 64·0 61·5 61·1 59·5 59·4 59·5 59·2 59·1 0·7 1·5 1·3 1·8 1·8 1·9 2·4 3·4 2·2 2·4 0·7 2·2 1·6 1·5 1·3 1·0 1·0 0·7 ·504 ·534 ·546 ·554 ·565 ·580 ·566 ·541 ·571 ·554 ·597 ·549 ·542 ·515 ·512 ·514 ·508 ·507 5·65 6·03 6·10 6·12 6·27 6·44 6·13 6·00 6·32 6·13 6·62 6·12 6·03 5·74 5·72 5·75 5·70 5·68 ·988 ·950 ·960 ·945 ·945 ·940 ·923 ·892 ·930 ·924 ·978 ·928 ·948 ·952 ·960 ·968 ·965 ·975 22·373 ·348 ·338 ·345 ·334 ·304 ·310 ·325 ·281 ·292 –·243 ·296 ·311 ·352 ·366 ·371 ·379 +·382

AUGUST

No. of Obser- vations Hour Baro- meter corrected Temp. Air Dew Point Diff. Tension of Vapour Weight of Vapour Humi- dity Pressure of Dry Air 15 26 28 28 24 23 21 21 21 19 19 19 19 19 19 19 19 19 1 a.m. 8 9 10 11 Noon 1 p.m. 2 3 4 5 6 7 8 9 10 11 Midnight 22·909 ·904 ·915 +·917 ·915 ·905 ·898 ·884 ·873 ·855 –·853 ·863 ·865 ·878 ·890 +·893 ·892 ·889 59·8 62·1 63·1 64·3 64·7 64·7 65·3 65·0 64·8 63·9 63·2 62·3 61·6 61·1 60·7 60·3 60·1 60·0 59·5 61·5 61·9 62·7 63·1 63·4 63·3 63·4 63·1 62·4 61·7 60·8 60·4 60·2 60·0 59·7 59·7 59·4 0·3 0·6 1·2 1·6 1·6 1·3 2·0 1·6 1·7 1·5 1·5 1·5 1·2 0·9 0·7 0·6 0·4 0·6 ·514 ·549 ·558 ·572 ·580 ·586 ·584 ·586 ·579 ·568 ·554 ·538 ·531 ·527 ·523 ·518 ·517 ·513 5·70 6·13 6·20 6·35 6·42 6·50 6·48 6·50 6·43 6·30 6·15 6·00 5·92 5·88 5·85 5·78 5·79 5·73 ·992 ·980 ·962 ·950 ·948 ·958 ·940 ·950 ·943 ·952 ·952 ·952 ·962 ·970 ·976 ·980 ·988 ·980 +22·395 ·355 ·357 ·345 ·335 ·319 ·314 ·298 ·294 –·287 ·299 ·325 ·334 ·351 ·367 ·375 ·375 ·376

SEPTEMBER

No. of Obser- vations Hour Baro- meter corrected Temp. Air Dew Point Diff. Tension of Vapour Weight of Vapour Humi- dity Pressure of Dry Air 28 29 28 24 23 23 23 23 23 19 19 20 21 22 24 24 23 8 a.m. 9 10 11 Noon 1 p.m. 2 3 4 5 6 7 8 9 10 11 Midnight 23·000 ·013 +·018 ·009 22·995 ·980 ·962 ·947 –·944 ·944 ·948 ·958 ·975 ·986 +·991 ·989 ·994 59·2 60·1 60·8 61·6 62·4 62·7 62·8 62·3 61·8 60·3 59·4 58·7 58·2 57·8 57·4 57·0 56·7 58·1 58·5 59·5 60·0 60·5 60·5 60·4 60·0 59·9 58·6 58·4 57·4 57·0 56·6 56·4 55·9 55·4 1·1 1·6 1·3 1·6 1·9 2·2 2·4 2·3 1·9 1·7 1·0 1·3 1·2 1·2 1·0 1·1 1·3 ·492 ·497 ·514 ·523 ·533 ·532 ·531 ·522 ·521 ·498 ·496 ·479 ·473 ·467 ·463 ·456 ·449 5·50 5·57 5·77 5·83 5·93 5·92 5·90 5·83 5·82 5·58 5·58 5·60 5·33 5·25 5·23 5·15 5·07 ·968 ·945 ·958 ·950 ·942 ·942 ·925 ·924 ·940 ·940 ·968 ·960 ·962 ·960 ·968 ·962 ·927 22·508 ·526 ·504 ·506 ·462 ·448 ·431 ·425 –·423 ·446 ·452 ·479 ·502 ·519 ·528 ·533 +·545

OCTOBER (22 days)

No. of Obser- vations Hour Baro- meter corrected Temp. Air Dew Point Diff. Tension of Vapour Weight of Vapour Humi- dity Pressure of Dry Air 11 19 20 20 19 13 15 13 13 14 16 13 6 7 3 7 14 18 14 6-6.30 7 a.m. 8 9 10 11 Noon 1 p.m. 2 3 4 5 6 7 8 9 10 11 Midnight 23·066 ·072 ·086 ·099 +·100 ·079 ·072 ·055 ·033 ·027 ·024 –·022 ·033 ·045 ·038 ·061 +·072 ·067 ·068 54·4 54·3 55·2 56·3 57·1 57·6 57·9 58·0 57·7 57·9 57·9 56·6 55·9 55·4 53·7 55·1 54·6 54·5 54·1 52·7 52·3 53·7 54·4 55·5 55·6 56·1 56·4 56·6 56·2 56·1 54·8 54·4 53·8 53·3 54·1 53·0 53·0 52·8 1·7 2·0 1·5 1·9 1·6 2·0 1·8 1·6 1·1 1·7 1·8 1·8 1·5 1·6 0·4 1·0 1·6 1·5 1·3 ·409 ·403 ·423 ·434 ·450 ·451 ·459 ·463 ·466 ·460 ·458 ·439 ·433 ·424 ·417 ·429 ·413 ·413 ·411 4·65 4·58 4·78 4·90 5·07 5·08 5·15 5·17 5·25 5·16 5·15 4·98 4·90 4·80 4·75 4·83 4·82 4·82 4·65 ·943 ·025 ·950 ·935 ·942 ·935 ·940 ·950 ·962 ·940 ·940 ·948 ·950 ·950 ·990 ·965 ·949 ·950 ·962 22·657 +·669 ·663 ·665 ·650 ·728 ·613 ·592 ·567 ·567 ·–·566 ·583 ·600 ·621 ·621 ·632 ·659 ·654 ·657

G.

ON THE RELATIVE HUMIDITY, AND ABSOLUTE AMOUNT OF VAPOUR CONTAINED IN THE ATMOSPHERE AT DIFFERENT ELEVATIONS IN THE SIKKIM HIMALAYA.

My observations for temperature and wet-bulb being for the most part desultory, taken at different dates, and under very different conditions of exposure, etc., it is obvious that those at one station are hardly, if at all, comparative with those of another, and I have therefore selected only such as were taken at the same date and hour with others taken at the Calcutta Observatory, or as can easily be reduced; which thus afford a standard (however defective in many respects) for a comparison. I need hardly remind my reader that the vapour-charged wind of Sikkim is the southerly one, which blows over Calcutta; that in its passage northwards to Sikkim in the summer months, it traverses the heated plains at the foot of the Himalaya, and ascending that range, it discharges the greater part of its moisture (120 to 140 inches annually) over the outer Himalayan ranges, at elevations of 4000 to 8000 feet. The cooling effect of the uniform covering of forest on the Sikkim ranges is particularly favourable to this deposition, but the slope of the mountains being gradual, the ascending currents are not arrested and cooled so suddenly as in the Khasia mountains, where the discharge is consequently much greater. The heating of the atmosphere, too, over the dry plains at the foot of the outer range, increases farther its capacity for the retention of vapour, and also tends to render the rain-fall less sudden and violent than on the Khasia, where the south wind blows over the cool expanse of the Jheels. It will be seen from the following observations, that in Sikkim the relative humidity of the atmosphere remains pretty constantly very high in the summer months, and at all elevations, except in the rearward valleys; and even there a humid atmosphere prevails up to 14,000 feet, everywhere within the influence of the snowy mountains. The uniformly high temperature which prevails throughout the summer, even at elevations of 17,000 and 18,000 feet, is no doubt proximately due to the evolution of heat during the condensation of these vapours. It will be seen by the pages of my journal, that continued sunshine, and the consequent heating of the soil, is almost unknown during the summer, at any elevation on the outer or southward ranges of Dorjiling: but the sunk thermometer proves that in advancing northward into the heart of the mountains and ascending, the sun’s effect is increased, the temperature of the earth becoming in summer considerably higher than that of the air. With regard to the observations themselves, they may be depended upon as comparable with those of Calcutta, the instruments having been carefully compared, and the cases of interpolation being few. The number of observations taken at each station is recorded in a separate column; where only one is thus recorded, it is not to be regarded as a single reading, but the mean, of several taken during an hour or longer period. I have rejected all solitary observations, even when accompanied by others at Calcutta; and sundry that were, for obvious reasons, likely to mislead. Where many observations were taken at one place, I have divided them into sets, corresponding to the hours at which alone the Calcutta temperature and wet-bulb thermometer are recorded,[423] in order that meteorologists may apply them to the solution of other questions relating to the distribution of heat and moisture. The Dorjiling observations, and those in the immediate neighbourhood of that station, appeared to me sufficiently numerous to render it worth while classing them in months, and keeping them in a series by themselves. The tensions of vapour are worked from the wet-bulb readings by Apjohn’s formula and tables, corrected for the height of the barometer at the time. The observations, except where otherwise noted, are taken by myself.

[423] Sunrise; 9.50 a.m.; noon; 2.40 p.m.; 4 p.m., and sunset.

SERIES I. _Observations made at or near Dorjiling._

JANUARY, 1849

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 15 15 10 8 9 The Dale,[424] Mr. Muller’s … … … 6956 … … … … 9.50 a.m. Noon 2.40 p.m. 4 p.m. Sunset 42·9 45·8 48·3 48·6 46·5 32·4 33·8 37·4 37·8 37·1 10·5 12·0 10·9 10·8 9·4 ·202 ·212 ·241 ·244 ·238 67·5 72·9 76·1 75·1 71·8 55·3 55·7 55·1 54·8 54·9 12·2 17·2 21·0 20·3 16·9 ·446 ·455 ·444 ·440 ·441 57 … … Mean 46·4 35·7 10·7 ·227 72·7 55·2 17·5 ·445

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·700 2·63 gr. 0·562 4·86 gr.

[424] Observations were taken by Mr. Muller.

JANUARY, 1850

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 3 6 3 5 5 5 13 4

1 Jillapahar, Mr. Hodgson’s … … … … … Saddle of road at Sinchul Pacheem 7430 … … … … … … 7412

7258 Sunrise 9.50 a.m. Noon 2.40 p.m. 4 p.m. Sunset Miscel. Do.

Do. 32·8 39·5 42·4 41·9 41·1 38·7 41·9 41·1

39·8 30·1 34·7 38·0 37·8 38·5 35·6 39·9 36·4

38·7 2·7 4·8 4·4 4·1 2·6 3·1 2·0 4·7

1·1 ·186 ·219 ·246 ·244 ·250 ·226 ·263 ·233

·252 51·5 66·9 74·1 78·3 77·4 72·4 77·9 67·7

71·6 48·5 55·1 51·7 51·4 59·5 54·7 60·1 57·2

50·5 3·0 11·8 22·4 26·9 17·9 17·7 17·8 10·5

21·1 ·354 ·444 ·395 ·391 ·514 ·438 ·525 ·476

·379 45 … … Mean 39·9 36·6 3·3 ·235 70·9 54·3 16·6 ·435

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·890 2·75 gr. 0·580 4·86 gr.

FEBRUARY, 1850

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 6 18 12 12 17 19 13 Jillapahar … … … … … The Dale[425] 7430 … … … … … 6956 Sunrise 9.50 a.m. Noon 2.40 p.m. 4 p.m. Sunset Misc. 36·9 42·9 44·8 44·8 44·0 42·4 40·8 34·7 38·6 41·3 37·4 35·6 35·8 35·1 2·2 4·3 3·5 7·4 8·4 6·6 5·7 ·219 ·251 ·276 ·241 ·226 ·228 ·222 60·0 72·8 79·8 82·4 81·1 76·3 69·9 54·2 58·8 58·7 57·9 58·1 60·7 59·8 5·8 14·0 21·1 24·5 23·0 15·6 10·1 ·431 ·503 ·501 ·487 ·492 ·536 ·518 97 … … Mean 42·4 36·9 5·4 ·238 74·6 58·3 16·3 ·495

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·828 2·75 gr. 0·590 5·40 gr.

[425] Observations were taken by Mr. Muller.

MARCH, 1850

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 10 8 5 8 6 3 Jillapahar … … … … Pacheem 7430 … … … … 7258 9.50 a.m. Noon 2.40 p.m. 4 p.m. Sunset Miscel. 44·2 45·5 46·4 45·5 43·1 44·8 42·7 43·0 44·0 43·4 41·5 44·6 1·5 2·5 2·4 2·1 1·6 0·2 ·290 ·293 ·303 ·297 ·278 ·310 81·6 88·2 91·3 90·1 82·9 85·0 64·1 57·0 53·2 52·0 63·7 74·8 17·5 31·2 38·1 38·1 19·2 10·2 ·602 ·472 ·416 ·399 ·590 ·848 40 … … Mean 44·9 43·2 1·7 ·295 86·5 60·8 25·7 ·555

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·940 3·42 gr. 0·438 5·72 gr.

APRIL

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 3 3 1 7 2 4 3 Jillapahar, 1849 … … Dr. Campbell’s, 1850 … … … 7430 … … 6932 … … … 9.50 a.m. Noon 2.40 p.m. 9.50 a.m. Noon 4 p.m. 57·0 59·8 60·2 61·8 65·4 57·5 56·9 40·2 44·1 44·4 53·3 52·8 53·7 51·4 16·8 15·7 15·8 8·5 12·6 3·8 5·5 ·266 ·305 ·308 ·417 ·411 ·423 ·392 90·3 97·0 97·7 86·7 91·3 88·6 82·8 71·3 64·5 73·4 66·3 68·8 72·1 73·0 19·0 32·5 24·3 20·4 22·5 16·5 9·8 ·758 ·607 ·812 ·644 ·699 ·778 ·800 23 … … Mean 59·8 48·6 11·3 ·360 90·6 69·9 20·7 ·728

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·684 3·98 gr. 0·523 7·65 gr.

MAY

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 3 45 Smith’s Hotel, 1848 Colinton,[426] 1849 6863 7179 Miscel. Miscel. 57·2 60·4 55·0 57·9 2·2 1·5 ·443 ·466 88·6 90·0 78·4 77·2 10·2 12·8 ·951 ·917 48 … Mean 58·8 56·5 2·4 ·455 89·3 77·8 11·5 ·934

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·926 5·22 gr. 0·698 9·90 gr.

[426] Observations were taken by Mr. Muller.

JUNE

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 40 Colinton,[427] 7179 Miscel. 60·9 57·6 3·3 ·483 85·5 78·4 7·1 ·952

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·895 5·39 gr. 0·800 10·17 gr.

[427] Observations were taken by Mr. Muller.

JULY, 1848

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 18 25 24 16 31 31 31 Jillapahar … … … The Dale,[428] … … 7430 … … … 6952 … … 9.50 a.m. Noon 2.40 p.m. 4 p.m. 6 a.m. 2 p.m. 6 p.m. 63·2 65·0 64·7 63·8 60·2 66·3 63·0 61·4 62·6 62·3 61·5 58·7 63·3 60·9 1·8 2·4 2·4 2·3 1·5 3·0 2·1 ·548 ·570 ·565 ·550 ·537 ·621 ·575 87·0 89·0 88·1 87·2 81·3 88·0 84·8 79·4 80·0 79·4 79·5 79·0 79·6 79·2 7·6 9·0 8·7 7·7 2·3 8·4 5·6 ·983 1·001 ·983 ·985 ·969 ·989 ·977 176 … … Mean 63·7 61·5 2·2 ·567 86·5 79·4 7·0 ·984

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·929 6·06 gr. 0·800 10·45 gr.

[428] Observations were taken by Mr. Muller.

AUGUST, 1848

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 23 21 17 13 31 31 31 Jillapahar … … … The Dale,[429] … … 7430 … … … 6952 … … 9.50 a.m. Noon 2.40 p.m. 4 p.m. 6 a.m. 2 p.m. 6 p.m. 64·2 64·7 64·7 63·9 60·5 65·3 62·8 62·4 63·3 62·8 62·5 59·5 63·6 61·8 1·8 1·4 1·9 1·4 1·0 1·7 1·0 ·567 ·584 ·574 ·568 ·551 ·628 ·591 85·8 87·2 87·4 86·5 80·8 87·2 83·7 79·1 79·2 79·3 79·5 78·8 79·2 78·7 6·7 8·0 8·1 7·0 2·0 8·0 5·0 ·973 ·976 ·979 ·984 ·962 ·976 ·959 167 … … Mean 63·7 62·3 1·5 ·580 85·5 79·1 6·4 ·973

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·995 6·25 gr. 0·818 10·35 gr.

[429] Observations were taken by Mr. Muller.

SEPTEMBER, 1848

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 28 23 23 21 30 30 30 Jillapahar … … … The Dale,[430] … … 7430 … … … 6952 … … 9.50 a.m. Noon 2.40 p.m. 4 p.m. 6 a.m. 2 p.m. 6 p.m. 60·8 62·4 62·4 62·0 57·4 64·9 60·8 59·3 60·3 59·6 59·6 56·2 60·8 59·0 1·5 2·1 2·8 2·4 1·2 4·1 1·8 ·511 ·528 ·516 ·516 ·495 ·573 ·543 87·0 88·5 88·1 86·9 80·9 88·8 84·7 78·4 78·1 77·4 77·1 78·3 77·4 76·6 8·6 10·4 10·7 9·8 2·6 11·4 8·1 ·952 ·943 ·922 ·914 ·948 ·923 ·899 185 … … Mean 61·5 59·3 2·3 ·526 86·4 77·6 8·8 ·929

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·932 5·72 gr. 0·760 9·88 gr.

[430] Observations were taken by Mr. Muller.

OCTOBER, 1848

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 6 6 6 4 8 8 17 19 Jillapahar … … Goong. Ditto The Dale,[431] … … 7430 … … 7436 7441 6952 … … Noon 2.40 p.m. 4 p.m. Misc. Misc. 6 a.m. 2 p.m. 6 p.m. 55·9 55·7 55·6 48·3 51·2 55·2 61·4 56·9 55·3 54·9 54·9 48·3 50·2 52·7 56·3 54·2 0·6 0·8 0·7 0 1·0 2·5 5·1 2·7 ·446 ·440 ·441 ·352 ·376 ·439 ·497 ·463 84·4 86·0 85·2 81·2 80·7 76·1 87·0 82·8 75·3 73·3 74·4 73·7 66·9 74·2 71·2 73·9 9·1 12·7 10·8 7·5 13·8 1·9 15·8 8·9 ·863 ·808 ·837 ·819 ·657 ·834 ·756 ·824 74 … … Mean 55·0 53·4 1·7 ·432 82·9 72·9 10·1 ·800

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·950 4·74 gr. 0·658 8·55 gr.

[431] Observations were taken by Mr. Muller.

NOVEMBER AND DECEMBER, 1848

DORJILING CALCUTTA No. of Obs. Place Elev. (feet) Hour Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 4 8 6 9 19 The Dale[432] Nov./Dec. … December … 6952 … … … … 6 a.m. 2 p.m. 6 p.m. 2 p.m. 6 a.m. 45·6 60·0 50·6 49·7 44·0 41·4 48·3 44·7 41·7 40·5 4·2 11·7 5·9 8·0 3·5 ·277 ·355 ·311 ·280 ·269 67·9 83·3 77·3 79·3 75·8 64·7 65·2 63·1 59·0 62·6 3·2 18·1 14·2 20·3 13·2 ·610 ·621 ·579 ·505 ·569 46 … … Mean 49·9 43·3 6·7 ·298 76·7 62·9 13·8 ·577

Dorjiling Calcutta Humidity Vapour in cubic foot of atmosphere 0·798 3·40 gr. 0·640 6·27 gr.

[432] Observations were taken by Mr. Muller.

_Comparison of Dorjiling and Calcutta._

HUMIDITY WEIGHT OF VAPOUR IN CUBIC FOOT OF AIR No. of Obs. Month Dorjiling Calcutta Diff. Dorjiling Dorjiling Calcutta Diff. Calcutta 102 97 40 23 48 40 176 167 185 74 46 January February March April May June July August September October Nov. and Dec. –·795 ·828 ·940 ·684 ·926 ·895 ·929 +·955 ·932 ·950 ·798 ·572 ·590 –·438 ·523 ·698 ·800 ·800 +·818 ·760 ·658 ·640 +·224 +·238 +·502 +·161 +·228 +·095 +·129 +·136 +·172 +·292 +·158 –2·68 2·75 3·42 3·98 5·22 5·39 6·06 +6·25 5·72 4·74 6·27 –4.80 5·40 5·72 7·65 9·90 10·17 10·05 +10·35 9·88 8·55 6·27 +2·12 +2·65 +2·30 +3·67 +4·62 +4·78 +3·99 +4·10 +4·16 +3·81 +2·87 998 Mean 0·876 0·663 +·212 4·51 8·07 +3·55

It is hence evident, from nearly 1000 comparative observations, that the atmosphere is relatively more humid at Dorjiling than at Calcutta, throughout the year. As the southerly current, to which alone is due all the moisture of Sikkim, traverses 200 miles of land, and discharges from sixty to eighty inches of rain before arriving at Dorjiling, it follows that the whole atmospheric column is relatively drier over the Himalaya than over Calcutta; that the absolute amount of vapour, in short, is less than it would otherwise be at the elevation of Dorjiling, though the relative humidity is so great. A glance at the table at the end of this section appears to confirm this; for it is there shown that, at the base of the Himalaya, at an elevation of only 250 feet higher than Calcutta, the absolute amount of vapour is less, and of relative humidity greater, than at Calcutta.

SERIES II. _Observations at various Stations and Elevations in the Himalaya of East Nepal and Sikkim._

ELEVATION 735 TO 2000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 3 2 1 3 1 6 1 5 5 11

10 Katong Ghat, Teesta river Great Rungeet, at bridge Ditto Tambur river, E. Nepal Ditto Bhomsong, Teesta river Ditto Little Rungeet Pemiongchi, Great Rungeet Punkabaree Ditto Guard house (Gt. Rungeet) 735 818 818 1388 1457 1596 1596 1672 1840 1850 1850 1864 Dec. April May Nov. Nov. Dec. May Jan. Dec. March May April 60·2 82·8 77·8 60·6 64·2 58·6 68·2 51·0 54·6 70·1 73·5 73·7 55·3 63·5 60·3 57·0 59·1 52·0 66·4 50·2 53·7 55·6 68·3 63·8 4·9 19·3 17·5 3·6 5·1 6·6 1·8 0·8 0·9 14·5 5·2 9·9 ·447 ·588 ·528 ·473 ·507 ·399 ·647 ·377 ·424 ·472 ·687 ·592 73·2 95·8 91·7 73·3 77·3 71·6 82·6 58·5 73·5 79·2 83·7 92·4 56·7 61·9 78·3 62·7 63·4 57·0 77·4 58·0 66·2 62·6 77·9 67·0 16·5 33·9 13·4 10·6 13·9 14·6 5·2 0·5 7·3 16·6 5·8 25·4 ·468 ·557 ·947 ·571 ·585 ·474 ·923 ·489 ·642 ·570 ·938 ·660 48 Mean 66·3 58·8 7·5 ·512 79·4 65·8 13·6 ·652

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·717 5·57 gr. 0·663 6·88 gr.

ELEVATION 2000 TO 3000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 2 8 3 3 2 8 12 8 3 Singdong Mywa Guola, E. Nepal Pemmi river, E. Nepal Tambur river, E. Nepal Blingbong (Teesta) Lingo (Teesta) Serriomsa (Teesta) Lingmo (Teesta) Ditto 2116 2132 2256 2545 2684 2782 2820 2849 2952 Dec. Nov. Nov. Nov. May May Dec. May Dec. 60·5 66·2 55·6 57·3 72·6 75·8 64·1 68·6 56·4 53·4 57·5 53·9 51·6 64·0 67·3 56·8 64·6 53·5 7·1 8·7 1·7 5·7 8·6 8·5 7·3 4·0 2·9 ·419 ·481 ·426 ·394 ·597 ·666 ·469 ·610 ·420 72·1 75·7 62·9 75·0 81·7 90·7 70·8 87·9 69·5 52·9 68·7 62·3 63·7 73·6 77·7 62·4 74·9 66·5 19·2 7·0 0·6 11·3 8·1 13·0 8·4 13·0 3·0 ·411 ·697 ·566 ·591 ·817 ·932 ·567 ·851 ·647 49 Mean 64·1 58·1 6·1 ·498 76·3 67·0 9·3 ·675

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·820 5·45 gr. 0·740 7·13 gr.

ELEVATION 3000 TO 4000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 5 9 3 2 2 7 7 1 3 1 1 2 5 Kulhait river Ratong river Tambur river Chingtam Tikbotang Myong Valley Iwa river Ratong river Tukcham Pacheem village Yankoong Mikk Sunnook 3159 3171 3201 3404 3763 3782 3783 3790 3849 3855 3867 3912 3986 Jan. Jan. Nov. Nov. Dec. Oct. Dec. Jan. Nov. Jan. Dec. May Dec. 49·8 44·2 53·0 54·8 56·5 61·4 47·5 56·2 68·8 54·5 50·0 66·1 47·9 47·0 43·0 50·0 49·0 53·4 58·4 45·6 41·1 65·4 46·3 43·6 63·9 45·5 2·8 1·2 3·0 5·8 3·1 3·0 1·9 15·1 3·4 8·2 6·4 2·2 2·4 ·337 ·294 ·373 ·360 ·419 ·496 ·321 ·275 ·625 ·329 ·299 ·595 ·320 65·8 69·9 72·9 74·9 68·0 80·7 73·3 75·8 83·7 73·6 69·1 84·3 69·4 57·3 56·6 63·2 73·0 61·8 71·2 64·7 53·0 76·8 59·4 63·8 75·1 61·1 8·5 13·3 9·7 1·9 6·2 9·5 8·6 22·8 6·9 14·2 5·3 9·2 8·3 ·477 ·466 ·582 ·802 ·555 ·755 ·611 ·414 ·904 ·513 ·593 ·856 ·542 48 Mean 54·7 50·2 4·5 ·388 74·0 64·4 9·6 ·621

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·858 4·23 gr. 0·732 6·60 gr.

ELEVATION 4000 TO 5000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 3 4 2 3 7 3 6 7 10 5 5 2 16 6 4 4 2 4 7 6 3 6 11 9 Yangyading Gorh Namgah Taptiatok (Tambur) Myong Valley Jummanoo Nampok Chakoong Singtam Namten Purmiokshong Rungniok Singtam Cheadam Sablakoo Bheti Temi Lingtam Khersiong Ditto Tassiding Lingcham Dikkeeling Tchonpong 4111 4128 4229 4283 4345 4362 4377 4407 4426 4483 4521 4565 4575 4653 4676 4683 4771 4805 4813 4813 4840 4870 4952 4978 Dec. May Oct. Nov. Oct. Nov. Dec. May May Dec. Nov. Jan. Oct/Nov. Dec. Dec. Nov. May May Jan. Mar. Dec. Dec. Dec. Jan. 52·0 66·4 57·2 51·3 59·1 60·4 49·6 57·8 62·4 44·7 60·5 54·7 63·8 51·4 50·1 59·0 59·8 60·4 51·0 53·6 52·0 48·5 62·0 49·4 43·6 59·0 54·1 45·8 57·8 50·0 49·1 57·6 61·7 44·3 56·5 44·3 60·1 46·6 44·9 52·3 50·1 56·6 45·2 45·5 46·6 46·1 55·3 34·7 8·4 7·4 3·1 5·5 1·3 10·4 0·5 0·2 0·7 0·4 4·0 10·4 3·7 4·8 5·2 6·7 9·7 3·8 5·8 8·1 5·4 2·4 6·7 14·7 ·300 ·506 ·429 ·323 ·487 ·374 ·362 ·483 ·553 ·307 ·466 ·307 ·525 ·332 ·314 ·405 ·374 ·467 ·316 ·320 ·333 ·327 ·447 ·219 71·1 85·5 80·8 73·3 81·7 77·4 64·1 83·9 88·6 64·8 79·2 66·5 82·5 70·2 72·9 78·3 81·2 80·0 67·0 77·1 79·7 78·5 80·8 71·0 67·2 74·2 73·7 64·8 72·9 70·2 56·3 76·2 79·0 58·3 69·5 59·7 76·7 55·0 65·7 66·1 74·1 73·8 49·8 70·5 60·8 71·8 62·0 54·7 3·9 11·3 7·1 8·5 8·8 7·2 7·8 7·7 9·6 6·5 9·7 6·8 5·8 15·2 7·2 12·2 7·1 6·2 17·2 6·6 18·9 6·7 18·8 16·3 ·663 ·834 ·819 ·614 ·797 ·731 ·462 ·889 ·969 ·495 ·715 ·517 ·901 ·442 ·632 ·639 ·834 ·820 ·370 ·738 ·538 ·771 ·559 ·439 137 Mean 55·7 50·4 5·4 ·387 76·5 66·8 9·7 ·675

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·837 4·33 gr. 0·730 7·12 gr.

ELEVATION 5000 TO 6000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 4 4 2 7 5 3 4 6 8 8 7 6 8 5 6 3 8 6 3 4 6 16 2 4 3 3 3 3 2 3 3 22 21 20 21 21 Nampok Tengling Choongtam, sunrise Choongtam, 9.50 a.m. Choongtam, noon Choongtam, 2.45 p.m. Choongtam, 4 p.m. Choongtam, sunset Choongtam, 9.50 a.m. Choongtam, noon Choongtam, 2.40 p.m. Choongtam, 4 p.m. Choongtam, sunset Sulloobong Lingdam Makaroumbi Khabang Lingdam Yankutamg Namtchi Yoksun Ditto Loongtoon Sakkiazong Phadong, 8 a.m. Phadong, 9.50 a.m. Phadong, noon Phadong, 2.40 p.m. Phadong, 4 p.m. Phadong, sunset Tumloong Tumloong, 9. 50 a.m. Tumloong, noon Tumloong, 2.40 p.m. Tumloong, 4 p.m. Tumloong, sunset 5075 5257 5368 5368 5368 5368 5368 5368 5368 5368 5368 5368 5368 5277 5375 5485 5505 5554 5564 5608 5619 5619 5677 5625 5946 5946 5946 5946 5946 5946 5368 5976 5976 5976 5976 5976 May Jan. May May May May May May Aug. Aug. Aug. Aug. Aug. Nov. Dec. Nov. Dec. Dec. Dec. May Jan. Jan. Nov. Nov. Nov. Nov. Nov. Nov. Nov. Nov. Nov. Nov/Dec. Nov/Dec. Nov/Dec. Nov/Dec. Nov/Dec. 65·8 44·7 54·9 71·5 71·0 66·4 63·5 61·4 76·3 78·8 72·9 69·5 66·9 57·6 44·3 52·1 55·1 45·0 43·6 67·1 42·7 43·0 45·3 54·1 51·9 55·9 60·7 57·4 55·5 53·7 64·2 54·1 57·3 57·3 54·7 51·8 60·8 39·1 54·7 58·9 59·4 59·4 59·2 60·5 66·1 67·8 66·5 66·8 65·4 51·2 43·0 48·1 47·3 43·7 41·7 61·2 34·0 33·9 42·8 50·9 50·8 53·0 56·5 54·7 52·8 52·6 62·6 50·0 51·7 51·4 50·5 48·5 5·0 5·6 0·2 12·6 11·6 7·0 4·3 0·9 10·2 11·0 6·4 2·7 1·5 6·4 1·3 4·0 7·8 1·3 1·9 5·9 8·7 9·1 2·5 3·2 1·1 2·9 4·2 2·7 2·7 1·1 1·6 4·1 5·6 5·9 4·2 3·3 ·537 ·257 ·438 ·504 ·513 ·513 ·510 ·532 ·640 ·677 ·649 ·655 ·627 ·390 ·293 ·350 ·340 ·301 ·280 ·544 ·214 ·213 ·292 ·358 ·383 ·413 ·465 ·438 ·410 ·408 ·570 ·375 ·396 ·391 ·380 ·355 83·1 65·4 78·2 89·8 92·7 95·4 93·6 89·1 85·3 86·6 86·4 85·3 83·6 79·4 68·8 72·5 75·0 71·0 69·5 87·7 68·2 66·2 72·1 78·3 75·0 80·9 85·6 86·6 85·5 80·6 83·8 75·1 79·7 81·3 80·2 76·7 74·7 38·1 73·9 80·0 79·9 78·7 79·0 77·1 78·9 78·8 78·8 79·3 78·5 65·8 59·9 60·5 64·7 56·5 63·1 74·9 58·1 51·9 63·8 66·1 67·5 67·9 64·8 62·2 61·9 67·4 77·5 61·9 60·1 58·0 58·6 61·2 8·4 27·3 4·3 9·8 12·8 16·7 14·6 12·0 6·4 7·8 7·6 6·0 5·1 13·6 8·9 12·0 10·3 14·5 6·4 12·8 10·1 14·3 8·3 12·2 7·5 13·0 20·8 24·4 23·6 13·2 6·3 13·2 19·6 23·3 21·6 15·5 ·845 ·247 ·826 1·000 ·999 ·959 ·971 ·915 ·967 ·965 ·963 ·980 ·956 ·634 ·521 ·532 ·611 ·466 ·579 ·850 ·492 ·399 ·595 ·639 ·670 ·678 ·613 ·562 ·557 ·667 ·924 ·557 ·524 ·489 ·499 ·545 260 Mean 57·7 53·3 4·5 ·438 77·6 67·8 9·8 ·700

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·865 4·70 gr. 0·730 7·34 gr.

ELEVATION 6000 TO 7000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 5 11 11 4 2 4 4 3 1 10 4 6 7 4 Runkpo Leebong Ditto Dholeep Iwa River Dengha Kulhait River Latong Doobdi Pemiongchi Keadom Hee-hill Dumpook Changachelling 6008 6021 6021 6133 6159 6368 6390 6391 6472 6584 6609 6677 6678 6828 Nov. Feb. Jan. May Dec. Aug. Dec. Oct. Jan. Jan. Aug. Jan. Jan. Jan. 57·5 47·8 47·8 60·5 41·2 66·7 41·9 54·0 46·6 40·7 63·5 40·8 40·2 50·6 54·8 43·7 43·4 59·9 40·5 64·0 41·9 53·2 36·2 35·8 60·0 34·1 31·8 31·8 2·7 4·1 4·4 0·6 0·7 2·7 0 0·8 10·4 4·9 3·5 6·7 8·4 18·8 ·440 ·300 ·297 ·520 ·269 ·597 ·283 ·416 ·231 ·228 ·523 ·215 ·198 ·198 79·5 74·9 66·9 89·4 69·6 86·1 71·3 55·5 78·7 66·3 79·7 64·0 68·5 68·3 73·4 59·7 56·2 81·4 60·2 78·8 60·9 44·1 58·0 54·4 77·5 58·0 53·8 53·6 6·1 15·2 10·7 8·0 9·4 7·3 10·4 11·4 20·7 11·9 2·2 6·0 14·7 14·8 ·810 ·517 ·460 ·046 ·527 ·962 ·539 ·305 ·490 ·434 ·925 ·489 ·426 ·423 76 Mean 50·0 45·1 4·9 ·337 72·8 62·1 10·6 ·597

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·845 3·60 gr. 0·701 6·11 gr.

ELEVATION 7000 TO 8000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 1 2 8 1 1 4 8 Pemiongchi Goong Kampo-Samdong Hee-hill Ratong river Source of Balasun Goong ridge 7083 7216 7329 7289 7143 7436 7441 Jan. Nov. May/Aug. Jan. Jan. Oct. Oct. 46·2 49·0 59·1 51·3 36·5 48·3 51·2 33·5 48·5 58·2 26·4 25·3 48·3 50·2 12·7 0·5 0·9 24·9 11·2 0 1·0 ·210 ·355 ·493 ·163 ·157 ·352 ·376 76·8 79·7 83·6 72·8 60·0 81·2 80·7 51·8 69·1 77·4 56·6 52·9 73·7 66·9 25·0 10·6 6·2 16·2 7·1 7·5 13·8 ·396 ·705 ·922 ·466 ·412 ·819 ·657 35 Dorjiling Mean 48·8 41·5 7·3 ·301 76·4 64·1 12·8 ·625

From mean of above and Dorjiling Calcutta Humidity Weight of vapour 0·826 3·85 gr. 0·668 7·28 gr.

ELEVATION 8000 TO 9000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 4 2 1 2 3 4 6 9 1 11 12 7 4 7 10 12 10 10 4 5 6 8 11 11 7 6 8 10 1 1 Sinchul Sinchul Ascent of Tonglo Tambur river Sakkiazong Chateng Buckim Buckim Chateng Lachoong, 7 a.m. Lachoong, 9.50 a.m. Lachoong, noon Lachoong, 2.40 p.m. Lachoong, 4 p.m. Lachoong, sunset Lachoong, Miscellaneous Lamteng, 6 a.m. Lamteng, 9.50 a.m. Lamteng, noon Lamteng, 2.40 p.m. Lamteng, 4 p.m. Lamteng, sunset Zemu Samdong, 7 a.m. Zemu Samdong, 9.50 a.m. Zemu Samdong, noon Zemu Samdong, 2.40 p.m. Zemu Samdong, sunset Zemu Samdong, 4 p.m. Goong Tendong (top) 8607 8607 8148 8081 8353 8418 8659 8659 8752 8777 8777 8777 8777 8777 8777 8777 8884 8884 8884 8884 8884 8884 8976 8976 8976 8976 8976 8976 8999 8663 Jan. Apr. May Nov. Nov. Oct. Jan. Jan. May | | || || | Aug. | | and | | Oct. | | | | | | || | || | May, | | June, | | July | | and | | Aug. | | | | | | || | || | June | | and | | July | | | | | | || | || Nov. May 41·7 66·8 56·2 38·0 49·7 43·8 30·2 33·9 67·2 53·3 60·2 61·6 58·1 58·6 55·5 55·9 53·9 62·8 62·8 58·3 56·2 53·3 55·7 59·7 63·1 61·0 57·9 53·8 49·0 55·5 34·3 44·6 54·4 33·9 37·4 43·2 22·8 33·1 60·7 51·1 55·3 57·1 56·4 53·8 54·3 49·6 52·0 56·2 56·2 54·4 54·7 52·5 55·3 52·8 57·1 58·6 56·1 52·6 48·5 50·0 7·4 22·2 1·8 4·1 12·3 0·6 7·4 0·8 6·5 2·2 4·9 4·5 1·7 4·8 1·2 6·3 1·9 6·6 6·6 3·9 1·5 0·8 0·4 6·9 6·0 2·4 1·8 1·2 0·5 5·5 ·216 ·310 ·434 ·213 ·241 ·299 ·143 ·207 ·536 ·388 ·447 ·475 ·464 ·424 ·432 ·368 ·400 ·461 ·461 ·435 ·438 ·407 ·448 ·412 ·473 ·500 ·459 ·407 ·355 ·373 66·3 96·9 86·8 71·7 74·0 79·2 68·6 69·8 89·7 83·0 87·1 90·1 88·0 87·5 84·5 85·9 59·5 88·3 92·0 92·2 92·3 88·1 80·4 86·3 88·0 89·6 89·3 82·7 79·7 88·6 56·9 75·4 78·9 64·1 62·4 77·5 49·4 52·2 76·8 78·9 79·9 79·4 80·0 79·4 78·7 75·2 56·4 78·7 78·0 78·4 77·1 77·4 79·8 79·0 79·8 78·2 79·0 77·3 69·1 78·1 9·4 21·5 7·9 7·6 11·6 1·7 19·2 17·6 12·9 4·1 7·2 10·7 8·0 8·1 5·8 10·7 3·1 9·6 14·0 13·8 15·2 10·7 0·6 7·3 8·2 11·4 10·3 5·4 10·6 10·5 ·472 ·866 ·967 ·599 ·566 ·926 ·366 ·403 ·904 ·967 ·999 ·983 1·007 ·981 ·959 ·858 ·464 ·959 ·939 ·950 ·914 ·922 ·997 ·969 ·994 ·944 ·970 ·920 ·705 ·943 193 Mean 54·5 50·0 4·5 ·388 83·7 73·7 9·8 ·847

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·858 4·23 gr. 0·730 8·75 gr.

ELEVATION 9000 TO 10,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 4 8 4 1 1 Yangma Guola Nanki Singalelah Sakkiazong Zemu river 9279 9320 9295 9322 9828 Nov. Nov. Dec. Nov. June 37·8 42·3 36·2 53·5 60·0 33·1 38·3 35·7 33·3 47·6 4·7 4·0 0·5 20·2 12·4 ·207 ·249 ·227 ·209 ·343 72·7 52·2 70·9 80·0 93·3 61·4 48·3 62·1 57·3 81·9 11·3 3·9 8·8 22·7 11·4 ·549 ·352 ·560 ·478 1·062 18 Mean 46·0 37·6 8·4 ·247 73·8 62·2 11·6 ·600

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·747 2·80 gr. 0·724 6·28 gr.

ELEVATION 10,000 TO 11,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 13 5 4 2 2 4 10 4 3 16 17 9 8 9 15 4 Tonglo Nanki Yalloong river Tonglo top Yeunga Zemu river Wallanchoon Laghep Laghep Thlonok river, 7 a.m. Thlonok river, 9.50 a.m. Thlonok river, noon Thlonok river, 2.40 p.m. Thlonok river, 4 p.m. Thlonok river, sunset Yangma Valley 10,008 10,024 10,058 10,079 10,196 10,247 10,384 10,423 10,423 10,486 10,486 10,486 10,486 10,486 10,486 10,999 May Nov. Dec. May Oct. June Nov. Nov. Nov. June June June June June June Dec. 51·5 42·8 37·7 49·9 45·9 45·4 37·9 46·0 37·6 48·5 57·6 56·1 54·8 53·4 49·8 31·6 50·2 35·5 29·6 47·9 44·7 44·2 30·2 42·4 37·0 47·2 51·4 50·6 50·6 50·6 48·9 24·3 1·3 7·3 8·1 2·0 1·2 1·2 7·7 3·6 0·6 1·3 6·2 5·5 4·2 2·8 0·9 7·3 ·376 ·225 ·183 ·348 ·311 ·306 ·187 ·287 ·238 ·339 ·392 ·382 ·381 ·381 ·359 ·149 88·8 79·5 77·7 89·4 79·5 84·6 76·5 80·9 75·3 79·0 87·4 90·0 88·5 88·7 85·5 74·4 80·8 65·8 62·1 80·5 77·1 75·1 61·9 68·0 69·4 75·1 78·8 79·3 79·7 78·7 78·0 61·9 8·0 13·7 15·6 8·9 2·4 9·5 14·6 12·9 5·9 3·9 8·6 10·7 8·8 10·0 7·5 12·3 1·030 ·633 ·560 1·018 ·915 ·856 ·558 ·681 ·712 ·856 ·965 ·979 ·991 ·962 ·938 ·558 123 Mean 46·7 42·8 3·8 ·303 82·8 73·3 9·5 ·826

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·878 3·35 gr. 0·740 8·70 gr.

ELEVATION 11,000 TO 12,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 3 3 1 12 6 8 5 6 6 2 10 9 5 7 4 10 7 Barfonchen Punying Kambachen village Tallum, 7 a.m. Tallum, 9.50 a.m. Tallum, noon Tallum, 2.40 p.m. Tallum, 4 p.m. Tallum, sunset Kambachen Valley Yeumtong, 7 a.m. Yeumtong, 9.50 a.m. Yeumtong, noon Yeumtong 2.40 p.m. Yeumtong, 4 p.m. Yeumtong, sunset Yeumtong, Miscellaneous 11,233 11,299 11,378 11,482 11,482 11,482 11,482 11,482 11,482 11,484 11,887 11,887 11,887 11,887 11,887 11,887 11,887 Nov. Aug. Dec. July July July July July July Dec. | | | Aug., | | Sep., | | and | | Oct. | | | | | Oct. 36·8 50·2 43·3 50·4 58·1 57·9 55·7 54·3 48·8 30·4 44·4 53·6 54·5 48·8 48·4 42·0 43·5 31·9 49·5 32·5 47·8 50·5 50·8 50·2 50·1 47·3 26·0 43·8 48·9 48·3 47·4 47·1 35·9 37·1 4·9 0·7 10·8 2·6 7·6 7·1 5·5 4·2 1·5 4·4 0·6 4·7 6·2 1·4 1·3 6·1 6·4 ·198 ·367 ·203 ·347 ·380 ·384 ·377 ·375 ·340 ·161 ·302 ·360 ·353 ·342 ·338 ·229 ·239 76·3 84·5 80·0 85·0 88·1 89·7 89·3 90·3 86·6 69·9 83·0 87·5 89·7 87·2 85·2 60·6 83·7 69·6 78·8 61·2 80·3 79·7 81·3 80·6 79·4 80·0 59·5 78·9 78·7 77·2 77·2 77·8 58·5 69·7 6·7 5·7 18·8 4·7 8·4 8·4 8·7 10·9 6·6 10·4 4·1 8·8 12·5 10·0 7·4 2·1 14·0 ·719 ·963 ·544 1·010 ·993 1·043 1·020 ·981 1·001 ·515 ·967 ·959 ·917 ·915 ·934 ·497 ·720 104 Mean 48·3 43·8 4·5 ·311 83·3 74·6 8·7 ·865

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·860 3·46 gr. 0·760 9·00 gr.

ELEVATION 12,000 TO 13,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 9 9 7 7 7 8 2 1 3 7 5 1 1 6 3 4 4 4 4 6 23 13 6 Zemu river, 7 a.m. Zemu river, 9.50 a.m. Zemu river, noon Zemu river, 2.40 p.m. Zemu river, 4 p.m. Zemu river, sunset Tangma Valley Zemu river Chumanako Tungu, 7 a.m. Tungu, 9.50 a.m. Tungu, noon Tungu, 2.40 p.m. Tungu, sunset Tungu, sunrise Tungu, 9.50 a.m. Tungu, noon Tungu, 2.40 p.m. Tungu, 4 p.m. Tungu, sunset Tungu, Miscellaneous Tungu, Miscellaneous Tuquoroma 12,070 12,070 12,070 12,070 12,070 12,070 12,129 12,422 12,590 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,751 12,994 | | June | | and | | July | | | | | | || | || Nov. June Nov. July July July July July Oct. Oct. Oct. Oct. Oct. Oct. Oct. July Nov. 46·6 51·1 51·1 51·2 49·7 48·1 34·8 49·0 37·3 45·1 53·1 62·3 60·0 46·4 38·2 46·5 46·1 43·8 42·3 41·0 43·2 51·3 26·0 45·6 49·0 50·2 50·3 48·9 47·6 22·7 46·6 28·3 44·1 48·6 52·7 53·8 45·3 35·0 42·8 42·0 42·1 40·8 38·7 40·8 47·7 23·4 1·0 2·1 0·9 0·9 0·8 0·5 12·1 2·4 9·0 1·0 4·5 9·6 6·2 1·1 3·2 3·7 4·1 1·7 1·5 2·3 2·4 3·6 2·6 ·321 ·362 ·376 ·377 ·360 ·344 ·143 ·332 ·174 ·305 ·355 ·409 ·425 ·317 ·222 ·292 ·284 ·285 ·271 ·253 ·272 ·345 ·146 80·6 84·5 87·0 86·3 86·5 81·4 70·6 93·2 75·1 80·5 87·1 88·9 85·3 84·7 79·4 85·0 85·0 86·4 85·9 83·3 84·5 85·7 75·1 77·7 75·1 82·2 80·0 80·2 77·5 63·7 79·6 73·8 78·3 79·4 77·8 79·5 79·1 77·8 78·6 78·2 78·8 78·5 78·2 78·4 79·0 60·8 2·9 9·4 4·8 6·3 6·3 3·9 6·9 13·6 1·3 2·2 7·7 11·1 5·8 5·6 1·6 6·4 6·8 7·6 7·4 5·1 6·1 6·7 14·3 ·931 ·972 1·074 1·000 1·006 ·926 ·592 ·989 ·822 ·949 ·982 ·935 ·985 ·974 ·932 ·957 ·944 ·963 ·956 ·947 ·950 ·971 ·537 140 Mean 46·3 42·9 3·4 ·303 83·6 77·1 6·5 ·926

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·890 3·37 gr. 0·815 9·75 gr.

ELEVATION 13,000 TO 14,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 7 4 2 21 1 4 10 1 3 Mon Lepcha Mon Lepcha Tunkra valley Jongri Zemu river Choonjerma Yangma village Wallanchoon road Kambachen, below pass 13,090 13,073 13,111 13,194 13,281 13,288 13,502 13,505 13,600 Jan. Jan. Aug. Jan. June Dec. Nov./Dec. Nov. Dec. 27·1 25·6 45·0 22·7 46·7 39·0 33·8 28·0 40·0 18·5 16·4 43·5 10·5 46·7 11·1 18·6 9·5 18·6 8·6 9·2 1·5 12·2 0 27·9 15·2 18·5 21·4 ·122 ·113 ·298 ·091 ·334 ·093 ·123 ·088 ·123 70·0 71·7 81·2 70·6 92·9 69·8 78·9 66·4 72·9 50·8 49·4 78·7 53·2 86·6 61·8 62·1 61·8 62·2 19·2 21·8 2·5 17·4 6·2 8·0 16·8 4·6 10·7 ·527 ·373 ·962 ·417 1·230 ·555 ·561 ·555 ·563 53 Mean 34·2 21·5 12·6 ·154 74·9 63·0 11·9 · 636

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·634 1·61 gr. 0·678 6·28 gr.

ELEVATION 15,000 TO 16,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 1 1 8 12 6 4 8 10 16 8 6 3 2 1 1 Yangma valley Choonjerma pass Lachee-pia Momay, 7 a.m. Momay, 9.50 a.m. Momay, noon Momay, 2.40 p.m. Momay, 4 p.m. Momay, sunset Momay, Miscellaneous Momay, Miscellaneous Sittong Palung Kambachen pass Yeumtong 15,186 15,259 15,262 15,262 15,262 15,262 15,262 15,262 15,262 15,262 15,262 15,372 15,676 15,770 15,985 Dec. Dec. Aug. Sept. Sept. Sept. Sept. Sept. Sept. Sept. Oct. Oct. Oct. Dec. Sept. 42·2 34·3 42·0 39·4 50·9 51·7 49·7 44·4 41·5 47·6 40·9 38·6 44·6 26·5 44·6 20·7 10·5 41·6 34·7 41·7 43·6 41·9 41·3 38·6 41·4 36·5 29·8 39·8 15·9 43·7 21·5 23·8 0·4 4·7 9·2 8·1 7·8 3·1 2·9 6·2 4·4 8·8 4·8 10·6 0·9 ·133 ·091 ·279 ·219 ·280 ·299 ·283 ·276 ·252 ·277 ·234 ·184 ·262 ·111 ·300 80·8 77·9 85·5 80·5 87·6 89·5 90·0 88·7 84·2 87·4 83·9 84·0 86·8 78·0 88·8 62·0 60·6 79·4 78·8 78·8 79·7 78·3 77·6 78·4 78·6 69·3 77·5 78·5 58·5 80·5 18·8 17·3 6·1 1·7 8·8 9·8 11·7 11·1 5·8 8·8 14·6 6·5 8·3 19·5 8·3 ·559 ·534 ·982 ·966 ·963 ·990 ·949 ·928 ·952 ·956 ·710 ·926 ·954 ·498 1·016 87 Mean 42·6 34·8 7·8 ·232 84·9 74·4 10·5 ·859

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·763 2·55 gr. 0·719 8·95 gr.

ELEVATION 16,000 TO 17,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 1 3 1 5 6 1 Kanglachem pass Tunkra pass Wallanchoon pass Yeumtso Cholamoo lake Donkia mountain 16,038 16,083 16,756 16,808 16,900 16,978 Dec. Aug. Nov. Oct. Oct. Sept. 32·8 39·8 18·0 32·4 31·4 40·2 16·3 38·7 –6·0 25·1 20·2 25·9 16·5 1·1 24·0 7·3 11·2 14·3 ·110 ·252 ·046 ·156 ·130 ·160 80·7 86·0 79·9 85·0 79·8 87·6 61·1 78·7 57·6 75·7 68·4 78·8 19·6 7·3 22·3 9·3 11·4 8·8 ·543 ·959 ·483 ·872 ·690 ·963 17 Mean 32·4 20·0 12·4 ·142 83·2 70·1 13·3 · 752

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·640 1·53 gr. 0·658 7·80 gr.

ELEVATION 17,000 TO 18,500 FEET

EAST NEPAL AND SIKKIM CALCUTTA No. of Obs. Locality Elev. Month Temp. Dew Point Diff. Tens. Temp. Dew Point Diff. Tens. 1 1 1 3 2 2 Kinchinjhow Sebolah pass Donkia mountain Bhomtso Donkia pass Donkia pass 17,624 17,585 18,307 18,450 18,466 18,466 Sept. Sept. Sept. Oct. Sept. Oct. 47·5 46·5 38·8 54·0 41·8 40·1 30·9 34·6 35·3 4·4 30·3 25·0 16·6 11·9 3·5 49·6 11·5 15·1 ·191 ·218 ·224 ·072 ·188 ·155 85·7 88·8 90·7 91·1 84·1 86·5 79·7 80·0 79·3 61·1 78·4 65·5 6·0 8·8 11·4 20·0 5·7 21·0 ·991 1·002 ·981 ·543 ·950 ·627 10 Mean 44·8 26·8 18·0 ·175 87·8 74·0 12·2 · 849

East Nepal and Sikkim Calcutta Humidity Weight of vapour 0·532 1·90 gr. 0·648 8·78 gr.

SUMMARY

HUMIDITY WEIGHT OF VAPOUR No. of Obs. Elevations in Feet Stations Sikkim Calcutta Diff. Sikkim Sikkim Calcutta Diff. Sikkim 48 49 48 137 260 76 1023 193 18 123 104 140 53 87 17 10 735 to 2000 2000 to 3000 3000 to 4000 4000 to 5000 5000 to 6000 6000 to 7000 7000 to 8000 8000 to 9000 9000 to 10,000 10,000 to 11,000 11,000 to 12,000 12,000 to 13,000 13,000 to 14,000 15,000 to 16,000 16,000 to 17,000 17,000 to 18,000 9 9 13 23 15 13 14 13 5 10 6 6 9 8 6 5 ·717 ·820 ·858 ·837 ·865 ·845 ·826 ·858 ·747 ·878 ·860 ·890 ·634 ·763 ·640 ·532 ·663 ·740 ·732 ·730 ·730 ·701 ·668 ·730 ·724 ·740 ·760 ·815 ·678 ·719 ·658 ·648 +·054 ·080 ·116 ·107 ·135 ·144 ·158 ·128 ·023 ·138 ·100 ·075 –·044 +·044 ·018 –·116 5·57 5·45 4·23 4·33 4·70 3·60 3·85 4·23 2·80 3·35 3·46 3·37 1·61 2·55 1·53 1·90 6·88 7·13 6·60 7·12 7·34 6·71 7·28 8·75 6·28 8·70 9·00 9·75 6·28 8·95 7·80 8·78 –1·31 1·68 2·37 2·79 2·64 3·11 3·43 4·52 3·48 4·35 5·54 6·38 4·67 6·40 6·27 6·88 2386 154

Considering how desultory the observations in Sikkim are, and how much affected by local circumstances, the above results must be considered highly satisfactory: they prove that the relative humidity of the atmospheric column remains pretty constant throughout all elevations, except when these are in a Tibetan climate; and when above 18,000 feet, elevations which I attained in fine weather only. Up to 12,000 feet this constant humidity is very marked; the observations made at greater elevations were almost invariably to the north, or leeward of the great snowy peaks, and consequently in a drier climate; and there it will be seen that these proportions are occasionally inverted; and in Tibet itself a degree of relative dryness is encountered, such as is never equalled on the plains of Eastern Bengal or the Gangetic delta. Whether an isolated peak rising near Calcutta, to the elevation of 19,000 feet, would present similar results to the above, is not proven by these observations, but as the relative humidity is the same at all elevations on the outermost ranges of Sikkim, which attain 10,000 feet, and as these rise from the plains like steep islands out of the ocean, it may be presumed that the effects of elevation would be the same in both cases.

The first effect of this humid wind is to clothe Sikkim with forests, that make it moister still; and however difficult it is to separate cause from effect in such cases as those of the reciprocal action of humidity on vegetation, and vegetation on humidity, it is necessary for the observer to consider the one as the effect of the other. There is no doubt that but for the humidity of the region, the Sikkim Himalaya would not present the uniform clothing of forest that it does; and, on the other hand, that but for this vegetation, the relative humidity would not be so great.[433]

[433] Balloon ascents and observations on small mountainous islands, therefore, offer the best means of solving such questions: of these, the results of ballooning, under Mr. Welsh’s intrepid and skilful pioneering (see Phil. Trans. for 1853), have proved most satisfactory; though, from the time for observation being short, and from the interference of belts of vapour, some anomalies have not been eliminated. Islands again are still more exposed to local influences, which may be easily eliminated in a long series of observations. I think that were two islands, as different in their physical characters as St. Helena and Ascension, selected for comparative observations, at various elevations, the laws that regulate the distribution of humidity in the upper regions might be deduced without difficulty. They are advantageous sites, from differing remarkably in their humidity. Owing partly to the indestructible nature of its component rock (a glassy basalt), the lower parts of Ascension have never yielded to the corroding effects of the moist sea air which surrounds it; which has decomposed the upper part into a deep bed of clay. Hence Ascension does not support a native tree, or even shrub, two feet high. St. Helena, on the other hand, which can hardly be considered more favourably situated for humidity, was clothed with a redundant vegetation when discovered, and trees and tree-ferns (types of humidity) still spread over its loftiest summits. Here the humidity, vegetation, and mineral and mechanical composition reciprocate their influences.

The great amount of relative humidity registered at 6000 to 8000 feet, arises from most of the observations having been made on the outer range, where the atmosphere is surcharged. The majority of those at 10,000 to 12,000 feet, which also give a disproportionate amount of humidity, were registered at the Zemu and Thlonok rivers, where the narrowness of the valleys, the proximity of great snowy peaks, and the rank luxuriance of the vegetation, all favour a humid atmosphere.

I would have added the relative rain-fall to the above, but this is so very local a phenomenon, and my observations were so repeatedly deranged by having to camp in forests, and by local obstacles of all kinds, that I have suppressed them; their general results I have given in Appendix F.

I here add a few observations, taken on the plains at the foot of the Sikkim Himalaya during the spring months.

_Comparison between Temperature and Humidity of the Sikkim Terai and Calcutta, in March and April, 1849._

No. of Obs. Locality Elev. above sea. Feet TEMPERATURE DEW POINT TENSION SAT. C. T. C. T. C. T. C. T. 4 4 3 3 4 3 2 8 Rummai Belakoba Rangamally Bhojepore Thakyagunj Bhatgong Sahibgunj Titalya 293 368 275 404 284 225 231 362 82·2 92·8 84·2 90·1 84·9 87·4 80·2 85·5 70·6 85·5 75·0 81·2 77·1 74·9 68·0 80·0 61·7 62·6 68·7 54·1 61·3 64·7 66·2 55·4 60·5 63·0 62·5 44·3 60·8 54·6 53·1 56·1 ·553 ·570 ·695 ·429 ·547 ·611 ·642 ·448 ·532 ·578 ·568 ·308 ·537 ·436 ·414 ·459 ·517 ·382 ·605 ·313 ·466 ·480 ·635 ·376 ·717 ·485 ·665 ·295 ·588 ·512 ·409 ·459 31 Means 305 85·9 79·0 61·8 56·9 ·562 ·479 · 472 ·516 May, 1850 Kishengunj 131 89·7 K 78·6 76·7 K 71·4 ·904 K ·759 ·665 K ·793

Vapour in a cubic foot Kishengunj Calcutta 8·20 9·52 Terai Calcutta 5·08 5·90

Mean difference of temperature between Terai and Calcutta, from 31 observations in March, as above, excluding mimima, Terai Mean difference from 26 observations in March, including mimima, Terai Mean difference of temperature at Siligoree on May 1, 1850 Mean difference of temperature at Kishengunj on May 1, 1850 6·9 9·7 10·9 11·1

From the above, it appears that during the spring months, and before the rains commence, the belt of sandy and grassy land along the Himalaya, though only 3·5° north of Calcutta, is at least 6° or 7° colder, and always more humid relatively, though there is absolutely less moisture suspended in the air. After the rains commence; I believe that this is in a great measure inverted, the plains becoming excessively heated, and the temperature being higher than at Calcutta. This indeed follows from the well known fact that the summer heat increases greatly in advancing north-west from the Bay of Bengal to the trans-Sutledge regions; it is admirably expressed in the maps of Dove’s great work “On the Distribution of Heat on the Surface of the Globe.”

H.

ON THE TEMPERATURE OF THE SOIL AT VARIOUS ELEVATIONS.

These observations were taken by burying a brass tube two feet six inches to three feet deep, in exposed soil, and sinking in it, by a string or tied to a slip of wood, a thermometer whose bulb was well padded with wool: this, after a few hours’ rest, indicates the temperature of the soil. Such a tube and thermometer I usually caused to be sunk wherever I halted, if even for one night, except during the height of the rains, which are so heavy that they communicate to the earth a temperature considerably above that of the air.

The results proved that the temperature of the soil at Dorjiling varies with that of the month, from 46° to 62·2°, but is hardly affected by the diurnal variation, except in extreme cases. In summer, throughout the rains, May to October, the temperature is that of the month, which is imparted by the rain to the depth of eleven feet during heavy continued falls (of six to twelve inches a day), on which occasions I have seen the buried thermometer indicating a temperature above the mean of the month. Again, in the winter months, December and January, it stands 5° above the monthly mean; in November and February 4° to 5°; in March a few degrees below the mean temperature of the month, and in October above it; April and May being sunny, it stands above their mean; June to September a little below the mean temperature of each respectively.

The temperature of the soil is affected by:—1. The exposure of the surface; 2. The nature of the soil; 3. Its permeability by rain, and the presence of underground springs; 4. The sun’s declination; 5. The elevation above the sea, and consequently the heating power of the sun’s rays: and 6, The amount of cloud and sunshine. far from being sufficient to supply data for the exact estimation of the effects of the sun on the soil at any elevation or locality; they, however, indicate with tolerable certainty the main features of this phenomenon, and these are in entire conformity with more ample series obtained elsewhere. The result, which at first sight appears the most anomalous, is, that the mean temperature of the soil, at two or three feet depth, is almost throughout the year in India above that of the surrounding atmosphere. This has been also ascertained to be the case in England by several observers, and the carefully conducted observations of Mr. Robert Thompson at the Horticultural Society’s Gardens at Chiswick, show that the temperature of the soil at that place is, on the mean of six years, at the depth of one foot, 1° above that of the air, and at two feet 1·5°. During the winter months the soil is considerably (l° to 3°) warmer than the air, and during summer the soil is a fraction of a degree cooler than the air.

In India, the sun’s declination being greater, these effects are much exaggerated, the soil on the plains being in winter sometimes 9° hotter than the air; and at considerable elevations in the Himalaya very much more than that; in summer also, the temperature of the soil seldom falls below that of the air, except where copious rain-falls communicate a low temperature, or where forests interfere with the sun’s rays.

At considerable elevations these effects are so greatly increased, that it is extremely probable that at certain localities the mean temperature of the soil may be even 10° warmer than that of the air; thus, at Jongri, elevation 13,194 feet, the soil in January was 34·5°, or 19·2° above the mean temperature of the month, immediately before the ground became covered with snow for the remainder of the winter; during the three succeeding months, therefore, the temperature of the soil probably does not fall below that of the snow, whilst the mean temperature of the air in January may be estimated at about 20°, February 22°, March 30°, and April 35°. If, again, we assume the temperature of the soil of Jongri to be that of other Sikkim localities between 10,000 and 14,000 feet, we may assume the soil to be warmer by 10° in July (see Tungu observations), by 8° or 9° in September (see Yeumtong); by l0° in October (see Tungu); and by 7° to l0° in November (see Wallanchoon and Nanki). These temperatures, however, vary extremely according to exposure and amount of sunshine; and I should expect that the greatest differences would be found in the sunny climate of Tibet, where the sun’s heat is most powerful. Were nocturnal or terrestrial radiation as constant and powerful as solar, the effects of the latter would be neutralised; but such is not the case at any elevation in Sikkim.

This accumulated heat in the upper strata of soil must have a very powerful effect upon vegetation, preventing the delicate rootlets of shrubs from becoming frozen, and preserving vitality in the more fleshy, roots, such as those of the large rhubarbs and small orchids, whose spongy cellular tissues would no doubt be ruptured by severe frosts. To the burrowing rodents, the hares, marmots, and rats, which abound at 15,000 to 17,000 feet in Tibet, this phenomenon is even more conspicuously important; for were the soil in winter to acquire the mean temperature of the air, it would take very long to heat after the melting of the snow, and indeed the latter phenomenon would be greatly retarded. The rapid development of vegetation after the disappearance of the snow, is no doubt also proximately due to the heat of the soil, quite as much as to the increased strength of the sun’s direct rays in lofty regions.

I have given in the column following that containing the temperature of the sunk thermometer, first the extreme temperatures of the air recorded during the time the instrument was sunk; and in the next following, the mean temperature of the air during the same period, so far as I could ascertain it from my own observations.

SERIES I. _Soane Valley_

Locality Date Eleva- tion (feet) Depth (ft. in.) Temperature of sunk Thermometer Extreme Temperature of Air observed Approx. Mean Temp. of Air deduced Diff. between Air and sunk Therm. Muddunpore Nourunga Baroon Tilotho

Akbarpore Feb. 11 to 12 Feb. 12 to 13 Feb. 13 to 14 Feb. 15 to 16

Feb. 17 to 19 440 340 345 395

400 3 4 3 8 2 4 4 6 (2 ther.) 4 6 5 6 71·5 71·7 68·5 76·5

76·0 62·0 to 77·5 57·0 to 71·0 53·5 to 76·0 58·5 to 80·0

56·9 to 79·5 67·0 67·3 67·6 67·8

68·0 +4·5 3·4 1·9 8·7

8·0

SERIES II. _Himalaya of East Nepal and Sikkim_

Locality Date Eleva- tion (feet) Depth (ft. in.) Temperature of sunk Thermometer Extreme Temperature of Air observed Approx. Mean Temp. of Air deduced Diff. between Air and sunk Therm. Base of Tonglo Simsibong Tonglo saddle Tonglo summit Simonbong Nanki Sakkiazong Mywa guola Banks of Tambur higher up river Wallanchoon Yangma village Yangma river Bhomsong Tchonpong Jongri Buckeem Choongtam Junction of Thlonok and Zemu Tungu Tungu Lamteng Choongtam Lachoong Yeumtong Momay Yeumtso Lachoong Great Rungeet Leebong Kursiong Leebong Punkabaree

Jillapahar (Mr. Hodgson’s)

Superintendent’s house May 19 May 20 May 21 to 22 May 23 May 24 Nov. 4 to 5 Nov. 9 to 10 Nov. 17 to 18 Nov. 18 to 19 Nov. 19 to 20 Nov. 23 to 25 Nov. 30 to Dec. 3 Dec. 2 to 3 Dec. 24 to 25 Jan. 4 Jan. 10 to 11 Jan.12 May 19 to 25

June 13 to 16 July 26 to 30 Oct. 10 to 15 Aug. 1 to 3 Aug. 13 to 15 Aug. 17 to 19 Sept. 2 to 8 Sept. 10 to 14 Oct. 16 to 18 Oct. 24 to 25 Feb. 11 to 13 Feb. 14 to 15 Apr. 16 Apr. 22 May 1 | Aug. 15 to 16 | | Aug. 15 to 16 | | Aug. 20 to 22 | | Aug. 20 to 22 | | Sept. 9 | | Sept. 9 | | Oct. 6 | | Oct. 20 | | Feb. 18 to 28 | | Mar. 1 to 13 | | Apr. 18 to 20 | | Apr. 30 | Apr. 21 to 30 3,000 7,000 10,008 10,079 5,000 9,300 8,353 2,132 2,545 3,201 10,386 13,502 10,999 1,596 4,978 13,194 8,665 5,268

10,846 12,751 12,751 8,884 5,268 8,712 11,919 15,362 16,808 8,712 818 6,000 4,813 6,000 1,850 7,430 7,430 7,430 7,430 7,430 7,430 7,430 7,430 7,430 7,430 7,430 7,430 6,932 2 0 2 0 2 6 2 6 2 6 3 0 3 0 3 0 3 0 3 0 2 0 2 0 2 7 2 7 2 7 2 7 2 7 2 7

2 7 2 5 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 5 0 7 7 5 0 7 7 5 0 7 7 7 7 7 7 2 7 2 7 2 7 2 7 2 7 78 61·7 50·7[434] 49·7 69·7 51·5 53·2 73·0 71·0 64·5 43·5 to 45·0 37·3 to 38·0 41·4 to 42·0 64·5 to 65·0 55·0 34·5 43·2 62·5 to 62·7

51·2 59·0 to 56·5 50·8 to 52·5 62·2 to 62·5 72·1 66·3 to 66·0 55·5 to 56·1 52·5 to 51·5 43·5 to 43·0 60·2 65·0 50·8 to 52·0 64·5 61·8 to 62·0 80·0 62·0 to 62·8 61·5 to 62·3 61·6 to 61·7 60·7 60·2 60·5 60·0 58·5 46·0 to 46·7 46·3 to 48·3 55·3 to 56·0 57·4 58·8 to 60·2 67·5 to 67·0 59·0 to 59·5 47·5 to 57·5 47·5 to 53·2 51·2 to 55·5 33·0 to 50·5 37·8 to 55·0 41·0 to 85·0 48·0 to 65·0 44·3 to 60·0 25·0 to 49·7 20·0 to 46·0 23·0 to 40·0 42·8 to 71·3 33·0 to 54·8 3·7 to 34·0 40·0 to 29·8 48·0 to 78·3

38·2 to 57·2 38·0 to 62·3 34·5 to 53·3 47·5 to 78·2 54·8 to 82·0 43·5 to 68·7 39·5 to 59·5 31·0 to 62·5 4·0 to 52·0 39·0 to 62·6 56·0 to 71·0 41·5 to 56·0 63·0 to 60·0 54·0 to 67·8 68·2 to 78·0 58·0 to 66·0 58·0 to 66·0 58·7 to 67·8 58·7 to 67·8 56·2 to 65·0 56·2 to 65·0 52·0 to 61·0 49·7 to 55·2 36·0 to 52·8 34·5 to 53·3 46·0 to 61·3 46·0 to 61·3 48·5 to 65·8

52·5 52·5 52·5 41·2 46·1 63·4 55·6 51·6 37·4 33·0 27·9 57·1 43·9 15·3 32·4 63·2

49·8 50·0 41·1 57·0 72·0 57·0 47·2 41·6 30·6 52·0 63·5 46·0 63·0 60·0 76·0 61·5 61·5 61·7 61·7 60·0 60·0 58·5 56·5 43·0 46·0 54·0 55·0 58·0

– 1·8 – 1·8 – 1·8 + 9·7 + 7·1 + 9·6 +15·4 +12·9 + 7·6 + 4·7 + 3·6 + 6·6 +11·1 +19·2 +10·8 – 0·6

+ 1·4 + 7·7 +10·7 + 5·3 + 0·1 + 9·2 + 8·6 +10·4 +12·6 + 8·2 + 1·5 + 5·4 + 1·5 + 1·9 + 4·0 + 0·9 + 0·4 – 0·1 – 1·0 + 0·2 + 0·5 + 1·5 + 2·0 + 6·4 + 1·3 + 1·7 + 2·4 + 1·5

[434] Sheltered by trees, ground spongy and wet.

SERIES III. _Plains of Bengal_

Locality Date Eleva- tion (feet) Depth (ft. in.) Temperature of sunk Thermometer Extreme Temperature of Air observed Approx. Mean Temp. of Air deduced Diff. between Air and sunk Therm. Kishengunj Dulalgunj Banks of Mahanuddy river Ditto Ditto Maldah Mahanuddy river Ganges Bauleah Dacca May 3 to 4 May 7 May 8 May 9 May 10 May 11 May 14 May 15 May 16 to 18 May 28 to 30 131 130 100 100 100 100 100 100 130 72 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 2 7 §82·8 to 83·0 §81·3 †79·3 †87·5 †88·0 †88·8 †87·8 †88·0 87·8 to 89·8 84·0 to 84·3 70·0 to 85·7 74·3 to 90·3 75·0 to 91·5 77·8 to 92·5 78·5 to 91·5 75·3 to 91·3 71·0 to 91·7 73·0 to 87·8 78·0 to 106·5 75·3 to 95·5 82·0 82·0 83·0 83·0 82·3 82·3 82·3 82·3 80·5 83·3 +0·8 –0·7 –3·7 –4·5 –5·7 –6·5 –4·5 –5·7 +7·3 +0·9

SERIES IV. _Khasia Mountains_

Locality Date Eleva- tion (feet) Depth (ft. in.) Temperature of sunk Thermometer Extreme Temperature of Air observed Approx. Mean Temp. of Air deduced Diff. between Air and sunk Therm. Churra Churra Kala-panee Kala-panee Kala-panee Kala-panee Moflong Moflong Moflong Syong Syong Myrung Myrung Myrung Myrung Nunklow Nunklow Pomrang Pomrang June 28 to 25 Oct. 29 to Nov. 16 June 28 to 29 Aug. 5 to 7 Sept. 13 to 14 Oct. 27 to 28 June 30 to July 4 July 30 to Aug. 4 Oct. 25 to 27 July 29 to 30 Oct. 11 to 12 July 9 to 10 July 26 to 29 Oct. 12 to 17 Oct. 21 to 25 July 11 to 26 Oct. 17 to 21 Sept. 15 to 23 Oct. 6 to 10 4,226

5,302

6,062

5,725

5,647

4,688

5,143 2 7

2 7

2 7

2 7

2 7

2 7

2 7 *71·8 to 72·3 68·3 to 64·0 69·2 70·0 to 70·4 *70·2 *66·3 65·0 67·3 63·2 69·2 to 69·3 67·0 66·2 to 66·3 68·3 66·0 to 64·8 64·8 to 64·0 70·5 to 71·3 68·8 to 68·3 70·3 to 68·5 68·3 64·8 to 72·2 70·7 to 49·3 64·2 to 71·2 72·2 to 61·8 65·5 to 69·8 64·0 to 56·0 61·0 to 68·3 64·0 to 75·8 63·7 to 55·7 60·0 to 78·5 65·7 to 55·5 60·0 to 73·8 78·0 to 64·2 70·0 to 55·5 66·0 to 53·0 65·5 to 81·5 75·7 to 58·0 73·0 to 57·0 73·7 to 58·2 69·9 61·7 67·2 64·9 66·0 60·0 64·0 68·5 64·1 69·2 62·8 67·5 71·1 63·0 60·5 71·5 66·1 65·5 65·0 +2·2 +4·5 +2·0 +5·2 +4·2 +6·3 +2·2 –1·2 –0·9 +0·1 +4·2 –1·2 –2·8 +2·4 +3·9 –0·5 +2·5 +3·9 +3·3

* Hole full of rain-water. † Soil, a moist sand. § Dry sand.

SERIES V. _Jheels, Gangetic Delta, and Chittagong_

Locality Date Eleva- tion (feet) Depth (ft. in.) Temperature of sunk Thermometer Extreme Temperature of Air observed Approx. Mean Temp. of Air deduced Diff. between Air and sunk Therm. Silchar Silhet Noacolly Chittagong Chittagong Chittagong, flagstaff hill Hat-hazaree Sidhee Hattiah Seetakoond Calcutta† Nov. 27 to 30 Dec. 3 to 7 Dec. 18 to 19 Dec. 23 to 31 Jan. 14 to 16 Dec. 28 to 30 Jan. 4 to 5 Jan. 5 to 6 Jan. 6 to 9 Jan. 9 to 14 Jan. 16 to Feb. 5 116 133 20 191

151 20 20 20 20 18 2 7 77·7 to 75·8 73·5 to 73·7 73·3 72·5 to 73·0 73·3 to 73·7 72·0 to 71·8 71·3 71·0 *67·7 73·3 to 73·7 76·0 to 77·0 55·0 to 81·7 63·0 to 74·5 58·5 to 76·5 53·2 to 75·0 61·3 to 78·7 55·2 to 74·2 50·5 to 62·0 52·7 to 70·2 50·2 to 77·5 55·2 to 79·5 §56·5 to 82·0 69·1 69·5 69·5 63·8 65·5 65·3 65·0 65·0 64·5 70·2 69·3 +7·7 +3·1 +3·8 +9·0 +8·3 +6·6 +6·3 +6·0 +3·2 +3·3 +7·2

* Shaded by trees. † Observations at the Mint, etc., by Mr. Muller. § Observations for temperature of air, taken at the Observatory.

I.

ON THE DECREMENT OF TEMPERATURE IN ASCENDING THE SIKKIM HIMALAYA MOUNTAINS AND KHASIA MOUNTAINS

I have selected as many of my observations for temperature of the sir as appeared to be trustworthy, and which, also, were taken contemporaneously with others at Calcutta, and I have compared them with the Calcutta observations, in order to find the ratio of decrement of heat to an increase of elevation. The results of several sets of observations are grouped together, but show so great an amount of discrepancy, that it is evident that a long series of months and the selection of several stations are necessary in a mountain country to arrive at any accurate results. Even at the stations where the most numerous and the most trustworthy observations were recorded, the results of different months differ extremely; and with regard to the other stations, where few observations were taken, each one is affected differently from another at the same level with it, by the presence or proximity of forest, by exposure to the east or west, to ascending or descending currents in the valleys, and to cloud or sunshine. Other and still more important modifying influences are to be traced to the monthly variations in the amount of humidity in the air and the strength of its currents, to radiation, and to the evolution of heat which accompanies condensation raising the temperature of elevated regions during the rainy season. The proximity of large masses of snow has not the influence I should have expected in lowering the temperature of the surrounding atmosphere, partly no doubt because of the more rapid condensation of vapours which it effects, and partly because of the free circulation of the currents around it. The difference between the temperatures of adjacent grassy and naked or rocky spots, on the other hand, is very great indeed, the former soon becoming powerfully heated in lofty regions where the sun’s rays pass through a rarefied atmosphere, and the rocks especially radiating much of the heat thus accumulated, for long after sunset. In various parts of my journals I have alluded to other disturbing causes, which being all more or leas familiar to meteorologists, I need not recapitulate here. Their combined effects raise all the summer temperatures above what they should theoretically be.

In taking Calcutta as a standard of comparison, I have been guided by two circumstances; first, the necessity of selecting a spot where observations were regularly and accurately made; and secondly, the being able to satisfy myself by a comparison of my instruments that the results should be so far strictly comparable.

I have allowed 1° Fahr. for every degree in latitude intervening between Sikkim and Calcutta, as the probable ratio of diminution of temperature. So far as my observations made in east Bengal and in various parts of the Gangetic delta afford a means of solving this question, this is a near approximation to the truth. The spring observations however which I have made at the foot of the Sikkim Himalaya would indicate a much more rapid decrement; the mean temperature of Titalya and other parts of the plains south of the forests, between March and May being certainly 6°–9° lower than Calcutta: this period however is marked by north-west and north-east winds, and by a strong haze which prevents the sun’s rays from impinging on the soil with any effect. During the southerly winds, the same region is probably hotter than Calcutta, there being but scanty vegetation, and the rain-fall being moderate.

In the following observations solitary readings are always rejected.

I.—_Summer or Rainy Season observations at Dorjiling._

Observations taken during the rainy season of 1848, at Mr. Hodgson’s (Jillapahar, Dorjiling) alt. 7,430 feet, exposure free to the north east and west, the slopes all round covered with heavy timber; much mist hence hangs over the station. The mean temperatures of the month at Jillapahar are deduced from horary observations, and those of Calcutta from the mean of the daily maximum and minimum.

Month No. of Obs. at Jillapahar Temp. Temp. Calcutta Equiv. of 1° Fahr. July August September October 284 378 407 255 61·7 61·7 58·9 55·3 86·6 85·7 84·7 83·3 364 feet 346 feet 348 feet 316 feet 1,324 … Mean 344 feet

II.—_Winter or dry season observations at Dorjiling._

1. Observations taken at Mr. J. Muller’s, and chiefly by himself, at “the Dale”; elev. 6,956 feet; a sheltered spot, with no forest near, and a free west exposure. 103 observations. Months: November, December, January, and February 1°=313 ft. 2. Observations at Dr. Campbell’s (Superintendent’s) house in April; elev. 6,950 feet; similar exposure to the last. 13 observations in April 1°=308 ft. 3. Observations by Mr. Muller at Colinton; elev. 7,179 feet; free exposure to north-west; much forest about the station, and a high ridge to east and south. 38 observations in winter months 1°=290 ft. 4. Miscellaneous (11) observations at Leebong; elev. 6000 feet; in February; free exposure all round 1°=266 ft. 5. Miscellaneous observations at “Smith’s Hotel;” Dorjiling, on a cleared ridge; exposed all round; elev. 6,863 feet. April and May 1°=252 ft. ———— Mean of winter observations Mean of summer observations

Mean 1°=286 ft. 1°=344 ft. ———— 310 ft.

III.—_Miscellaneous observations taken at different places in Dorjiling, elevations 6,900 to 7,400 feet, with the differences of temperature between Calcutta and Dorjiling._

Month Number of Observations Difference of Temperature Equivalent January February March April March and April July August September October 27 84 37 7 29 83 74 95 18 30·4 32·8 41·9 36·0 37·3 23·6 22·4 25·7 29·5 1°=287 ft. 1°=265 ft. 1°=196 ft. 1°=236 ft. 1°=224 ft. 1°=389 ft. 1°=415 ft. 1°=350 ft. 1°=297 ft. Sum 454 Mean 31·1 Mean 1°=295 ft.

These, it will be seen, give a result which approximates to that of the sets I and II. Being deduced from observations at different exposures, the effects of these may be supposed to be eliminated. It is to be observed that the probable results of the addition of November and December’s observations, would be balanced by those of May and June, which are hot moist months.

IV.—_Miscellaneous cold weather observations made at various elevations between 1000 and 17,000 feet, during my journey into east Nepal and Sikkim, in November to January 1848 and 1849. The equivalent to 1° Fahr. was deduced from the mean of all the observations at each station, and these being arranged in sets corresponding to their elevations, gave the following results._

Elevation Number of Stations Number of Observations Equivalent 1,000 to 4,000 ft. 4,000 to 8,000 ft. 8,000 to 12,000 ft. 12,000 to 17,000 ft. 27 52 20 14 111 197 84 54 1°=215 ft. 1°=315 ft. 1°=327 ft. 1°=377 ft. Sum 113 Sum 446 Mean 1°=308 ft.

The total number of comparative observations taken during that journey, amounted to 563, and the mean equivalent was 1°=303 feet, but I rejected many of the observations that were obviously unworthy of confidence.

V.—_Miscellaneous observations (chiefly during the rainy season) taken during my journey into Sikkim and the frontier of Tibet, between May 2nd and December 25th, 1848. The observations were reduced as in the previous instance. The rains on this occasion were unusually protracted, and cannot be said to have ceased till mid-winter, which partly accounts for the very high temperatures._

Elevation Number of Stations Number of Observations Equivalent 1,000 to 4,000 ft. 4,000 to 8,000 ft. 8,000 to 12,000 ft. 12,000 to 17,000 ft. 10 21 18 29 45 283 343 219 1°=422 ft. 1°=336 ft. 1°=355 ft. 1°=417 ft. Sum 78 Sum 890 Mean 1°=383 ft.

The great elevation of the temperature in the lowest elevations is accounted for by the heating of the valleys wherein these observations were taken, and especially of the rocks on their floors. The increase with the elevation, of the three succeeding sets, arises from the fact that the loftier regions are far within the mountain region, and are less forest clad and more sunny than the outer Himalaya.

A considerable number of observations were taken during this journey at night, when none are recorded at Calcutta, but which are comparable with contemporaneous observations taken by Mr. Muller at Dorjiling. These being all taken during the three most rainy months, when the temperature varies but very little during the whole twenty-four hours, I expected satisfactory results, but they proved very irregular and anomalous.

The means were— At 21 stations of greater elevation than Dorjiling 1°=348 ft. At 17 stations lower in elevation 1°=447 ft.

VI.—_Sixty-four contemporaneous observations at Jillapahar, 7,430 feet, and the bed of the Great Rungeet river, 818 feet; taken in January and February, give 1°=322 feet._

VII.—_Observations taken by burying a thermometer two and a half to three feet deep, in a brass tube, at Dorjiling and at various elevations near that station._

Month Upper Stations Lower Stations February and March February

April April March and April March, April, May Jillapahar, 7,430 ft. Ditto

Leebong, 6000 ft. Jillapahar, 7,430 ft. Khersiong, 4,813 ft. Jillapahar, 7,430 ft. Leebong, 6000 ft. Guard House, Great Rungeet, 1,864 ft. Ditto Khersiong, 4,813 ft. Punkabaree, 1,850 ft. Ditto 1°=269 ft.

1°=298 ft. 1°=297 ft. 1°=297 ft. 1°=223 ft. 1°=253 ft. Mean 1°=273 ft.

The above results would seem to indicate that up to an elevation of 7,500 feet, the temperature diminishes rather more than 1° Fahr. for every 300 feet of ascent or thereabouts; that this decrement is much leas in the summer than in the winter months; and I may add that it is less by day than by night. There is much discrepancy between the results obtained at greater or less elevations than 7000 feet; but a careful study of these, which I have arranged in every possible way, leads me to the conclusion that the proportion map be roughly indicated thus:—

1°=300 feet, for elevations from 1,000 to 8,000 feet. 1°=320 feet, for elevations from 8,000 to 10,000 feet. 1°=350 feet, for elevations from 10,000 to 14,000 feet. 1°=400 feet, for elevations from 14,000 to 18,000 feet.

VIII.—_Khasia mountain observations._

Date Calcutta Obs. Number of Obs. Churra Obs. Number of Obs. Altitude above the Sea Churra Poonji, June 13 to 26 Churra Poonji, Aug. 7 to Sept. 4 Churra Poonji, Oct. 29 to Nov. 16 86·3 84·6 80·7 63 196 85 70·1 69·2 63·1 67 214 133 1°=300 ft. 1°=331 ft. 1°=282 ft. 4,069 ft. 4,225 ft. 4,225 ft. 354 414 Mean, 304 ft.

Date Calcutta Obs. Number of Obs. Khasia Obs. Number of Obs. Altitude above the Sea Kala-panee, June, Aug., Sept. Moflong, June, July, Aug., Oct. Syong Myrung, Aug. Myrung, Oct. Nunklow Mooshye, Sept. 23 Pomrang, Sept. 23 Amwee, Sept. 23 Joowy, Sept. 23 85·5 85·9 85·1 89·1 82·9 86·4 78·5 82·7 79·9 79·5 35 73 4 42 21 139 9 51 15 11 67·4 68·8 65·0 69·7 63·2 70·9 66·3 65·8 67·1 69·0 35 74 6 41 58 139 12 51 11 7 1°=345 ft. 1°=373 ft. 1°=332 ft. 1°=343 ft. 1°=336 ft. 1°=372 ft. 1°=499 ft. 1°=369 ft. 1°=396 ft. 1°=567 ft. 5,302 ft. 6,062 ft. 5,734 ft. 5,632 ft. 5,632 ft. 4,688 ft. 4,863 ft. 5,143 ft. 4,105 ft. 4,387 ft. 400 434 1°=385 ft.

The equivalent thus deduced is far greater than that brought out by the Sikkim observations. It indicates a considerably higher temperature of the atmosphere, and is probably attributable to the evolution of heat during extraordinary rain-fall, and to the formation of the surface, which is a very undulating table-land, and everywhere traversed by broad deep valleys, with very steep, often precipitous flanks; these get heated by the powerful sun, and from them, powerful currents ascend. The scanty covering of herbage too over a great amount of the surface, and the consequent radiation of heat from the earth, must have a sensible influence on the mean temperature of the summer months.

J.

ON THE MEASUREMENT OF ALTITUDES BY THE BOILING-POINT THERMOMETER.

The use of the boiling-point thermometer for the determination of elevations in mountainous countries appearing to me to be much underrated, I have collected the observations which I was enabled to take, and compared their results with barometrical ones.

I had always three boiling-point thermometers in use, and for several months five; the instruments were constructed by Newman, Dollond, Troughton, and Simms, and Jones, and though all in one sense good instruments, differed much from one another, and from the truth. Mr. Welsh has had the kindness to compare the three best instruments with the standards at the Kew Observatory at various temperatures between 180° and the boiling-point; from which comparison it appears, that an error of l·5° may be found at some parts of the scale of instruments most confidently vouched for by admirable makers. Dollond’s thermometer, which Dr. Thomson had used throughout his extensive west Tibetan journeys, deviated but little from the truth at all ordinary temperatures. All were so far good, that the errors, which were almost entirely attributable to carelessness in the adjustments, were constant, or increased at a constant ratio throughout all parts of the scale; so that the results of the different instruments have, after correction, proved strictly comparable.

The kettle used was a copper one, supplied by Newman, with free escape for the steam; it answered perfectly for all but very high elevations indeed, where, from the water boiling at very low temperatures, the metal of the kettle, and consequently of the thermometer, often got heated above the temperature of the boiling water.

I found that no confidence could be placed in observations taken at great elevations, by plunging the thermometer in open vessels of boiling water, however large or deep, the abstraction of heat from the surface being so rapid, that the water, though boiling below, and hence bubbling above, is not uniformly of the same temperature throughout.

In the Himalaya I invariably used distilled, or snow or rain-water; but often as I have tried common river-water for comparison, I never found that it made any difference in the temperature of the boiling-point. Even the mineral-spring water at Yeumtong, and the detritus-charged glacial streams, gave no difference, and I am hence satisfied that no objection can be urged against river waters of ordinary purity.

On several occasions I found anomalous rises and falls in the column of mercury, for which I could not account, except theoretically, by assuming breaks in the column, which I failed to detect on lifting the instrument out of the water; at other times, I observed that the column remained for several minutes stationary, below the true temperature of the boiling water, and then suddenly rose to it. These are no doubt instrumental defects, which I only mention as being sources of error against which the observer must be on the watch: they can only be guarded against by the use of two instruments.

With regard to the formula employed for deducing the altitude from a boiling-point observation, the same corrections are to a great extent necessary as with barometric observations: if no account is taken of the probable state of atmospheric pressure at the level of the sea at or near the place of observation, for the hour of the day and month of the year, or for the latitude, it is obvious that errors of 600 to 1000 feet may be accumulated. I have elsewhere stated that the pressure at Calcutta varies nearly one inch (1000 feet), between July and January; that the daily tide amounts to one-tenth of an inch (=100 feet); that the multiplier for temperature is too great in the hot season and too small in the cold; and I have experimentally proved that more accuracy is to be obtained in measuring heights in Sikkim, by assuming the observed Calcutta pressure and temperature to accord with that of the level of the sea in the latitude of Sikkim, than by employing a theoretical pressure and temperature for the lower station.

In the following observations, the tables I used were those printed by Lieutenant-Colonel Boileau for the East India Company’s Magnetic Observatory at Simla, which are based upon Regnault’s Table of the ‘Elastic Force of Vapour.’ The mean height of the barometrical column is assumed (from Bessel’s formula) to be 29·924 at temp. 32°, in lat. 45°, which, differing only ·002 from the barometric height corresponding to 212° Fahrenheit, as determined experimentally by Regnault, gives 29·921 as the pressure corresponding to 212° at the level of the sea.

The approximate height in feet corresponding to each degree of the boiling-point, is derived from Oltmann’s tables. The multipliers for the mean temperature of the strata of atmosphere passed through, are computed for every degree Fahrenheit, by the formula for expansion usually employed, and given in Baily’s Astronomical Tables and Biot’s Astronomie Physique.

For practical purposes it may be assumed that the traveller, in countries where boiling-point observations are most desired, has never the advantage of a contemporaneous boiling-point observation at a lower station. The approximate difference in height is hence, in most cases, deduced from the assumption, that the boiling-point temperature at the level of the sea, at the place of observation, is 212°, and that the corresponding temperature of the air at the level of the sea is hotter by one degree for every 330 feet of difference in elevation. As, however, the temperature of boiling water at the level of the sea varies at Calcutta between July and January almost from 210·7° to 212·6°, I always took the Calcutta barometer observation at the day and hour of my boiling-point observation, and corrected my approximate height by as many feet as correspond to the difference between the observed height of the barometer at Calcutta and 29·921; this correction was almost invariably (always normally) subtractive in the summer, often amounting to upwards of 400 feet: it was additive in winter, and towards the equinoxes it was very trifling.

For practical purposes I found it sufficient to assume the Calcutta temperature of the air at the day and hour of observation to be that of the level of the sea at the place of observation, and to take out the multiplier, from the mean of this and of the temperature at the upper station. As, however, 330 feet is a near approach to what I have shown (Appendix I) to be the mean equivalent of 1° for all elevations between 6000 and 18,000 feet; and as the majority of my observations were taken between these elevations, it results that the mean of all the multipliers employed in Sikkim for forty-four observations amounts to 65·1° Fahrenheit, using the Calcutta and upper station observations, and 65·3° on the assumption of a fall of 1° for every 330 feet. To show, however, how great an error may accrue in individual cases from using the formula of 1° to 330, I may mention that on one occasion, being at an elevation of 12,000 feet, with a temperature of the air of 70°, the error amounted to upwards of 220 feet, and as the same temperature may be recorded at much greater elevations, it follows that in such cases the formula should not be employed without modification.

A multitude of smaller errors, arising from anomalies in the distribution of temperature, will be apparent on consulting my observations on the temperature at various elevations in Sikkim; practically these are unavoidable. I have also calculated all my observations according to Professor J. Forbes’s formula of 1° difference of temperature of boiling-water, being the equivalent of 550 feet at all elevations. (See Ed. Phil. Trans., vol xv. p. 405.) The formula is certainly not applicable to the Sikkim Himalaya; on the contrary, my observations show that the formula employed for Boileau’s tables gives at all ordinary elevations so very close an approach to accuracy on the mean of many observations, that no material improvement in its construction is to be anticipated.

At elevations below 4000 feet, elevations calculated from the boiling-point are not to be depended on; and Dr. Thomson remarked the same in north-west India: above 17,000 feet also the observations are hazardous, except good shelter and a very steady fire is obtainable, owing to the heating of the metal above that of the water. At all other elevations a mean error of 100 feet is on the average what is to be expected in ordinary cases. For the elevation of great mountain masses, and continuously elevated areas, I conceive that the results are as good as barometrical ones; for the general purposes of botanical geography, the boiling-point thermometer supersedes the barometer in point of practical utility, for under every advantage, the transport of a glass tube full of mercury, nearly three feet long, and cased in metal, is a great drawback to the unrestrained motion of the traveller.

In the Khasia mountains I found, from the mean of twelve stations and twenty-three observations, the multiplier as derived from the mean of the temperature at the upper station and at Calcutta, to be 75.2°, and as deduced from the formula to be 73·1°. Here, however, the equivalent in feet for 1° temp. is in summer very high, being 1°=385 feet. (See Appendix I.) The mean of all the elevations worked by the boiling-point is upwards of 140 feet below those worked by the barometer.

The following observations are selected as having at the time been considered trustworthy, owing to the care with which they were taken, their repetition in several cases, and the presumed accuracy of the barometrical or trigonometrical elevation with which they are compared. A small correction for the humidity of the air might have been introduced with advantage, but as in most barometrical observations, the calculations proceed on the assumption that the column of air is in a mean state of saturation; as the climate of the upper station was always very moist, and as most of the observations were taken during the rains, this correction would be always additive, and would never exceed sixty feet.

It must be borne in mind that the comparative results given below afford by no means a fair idea of the accuracy to be obtained by the boiling-point. Some of the differences in elevation are probably due to the barometer. In other cases I may have read off the scale wrong, for however simple it seems to read off an instrument, those practically acquainted with their use know well how some errors almost become chronic, how with a certain familiar instrument the chance of error is very great at one particular part of the scale, and how confusing it is to read off through steam alternately from several instruments whose scales are of different dimensions, are differently divided, and differently lettered; such causes of error are constitutional in individual observers. Again, these observations are selected without any reference to other considerations but what I have stated above; the worst have been put in with the best. Had I been dependent on the boiling-point for determining my elevations, I should have observed it oftener, or at stated periods whenever in camp, worked the greater elevations from the intermediate ones, as well as from Calcutta, and resorted to every system of interpolation. Even the following observations would be amended considerably were I to have deduced the elevation by observations of the boiling-point at my camp, and added the height of my camp, either from the boiling-point observations there, or by barometer, but I thought it better to select the most independent method of observation, and to make the level of the sea at Calcutta the only datum for a lower station.

SERIES I.—_Sikkim Observations._

Place Month Elevation by Barom. or Trigonom. Temp. B.P. Air Elevation by B.P. Error

Great Rungeet river Bhomsong Guard House, Great Rungeet Choongtam Dengha Mr. Muller’s (Dorjiling) Dr. Campbell’s (Dorjiling) Mr. Hodgson’s (Dorjiling) Sinchul Lachoong Lamteng Zemu Samdong Mainom Junction of Zemu & Thlonok Tallum Yeumtong Zemu river Tungu Jongri Zemu river Lachee-pia Momay Palung Kongra Lama Snow-bed above Yeumtong Tunkra pass Yeumtso Donkia Mountain above Momay Sebolah pass Kinchinjow Donkia Mountain Donkia Mountain Bhomtso Donkia pass Feb. Dec. Apr. Aug. Aug. Feb. Apr. Feb. Jan. Aug. Aug. July Dec. July July Sept. June July/Oct. Jan. June Aug. Sept. Oct. July Sept. Aug. Oct. Sept. Sept. Sept. Sept. Sept. Sept. Oct. Sept. (feet) B. 818 1,544 1,864 5,268 6,368 Tr. 6,925 6,932 B. 7,429 Tr. 8,607 B. 8,712 8,884 8,976 Tr. 10,702 B. 10,846 11,482 11,919 12,070 12,751 13,194 13,281 15,262 15,362 15,620 15,694 15,985 16,083 16,808 16,978 17,394 17,585 17,624 18,510 18,307 18,450 18,466 210·7 210·2 208·1 202·6 200·6 199·4 200·1 199·4 197·0 196·4 196·3 196·1 193·4 193·6 191·8 191·3 190·4 189·7 188·8 188·5 186·0 186·1 185·4 184·1 184·6 164·1 183·1 182·4 181·9 181·9 181·0 180·6 179·9 181·2 181·2 56·3 58·0 72·7 65·0 68·0 41·3 59·5 47·6 41·7 54·6 77·0 58·6 38·0 52·0 54·6 52·2 48·5 43·4 26·0 47·0 42·8 48·6 45·8 41·5 44·5 39·0 15·0 41·0 47·8 46·5 47·5 37·1 38·8 52·0 45·5 (feet) 904 1,321 2,049 5,175 6,246 7,122 6,745 7,318 8,529 8,777 8,937 8,916 10,516 10,872 11,451 11,887 12,139 12,696 13,151 13,360 14,912 14,960 15,437 16,041 15,816 16,317 16,279 17,049 17,470 17,517 18,026 18,143 18,597 18,305 17,866 (feet) + 86 – 223 + 185 – 93 – 122 + 197 – 187 – 111 – 78 + 65 + 53 – 60 – 186 + 26 – 31 – 32 + 69 – 55 – 43 + 79 – 350 – 402 – 183 + 347 – 169 + 54 – 529 + 71 + 76 – 68 + 402 – 367 + 290 – 145 – 600 Mean – 58

SERIES II.—_Khasia Observations._

Place Month Elevation by Barometer Temp. B.P. Air Elevation by B.P. Diff.

Churra Amwee Nurtiung Nunklow Kala-panee

Myrung Syong Moflong

Chillong June September October July June, July, Sept., Oct. July July July, Aug., Oct., Nov. November (feet) 4,069 4,105 4,178 4,688 5,302

5,647 5,725 6,062

6,662 204·4 205·1 205·0 203·9 202·2

201·9 201·8 201·4

201·2 70·3 67·7 70·0 69·8 65·8

69·4 70·8 64·8

62·8 (feet) 4,036 4,041 4,071 4,333 5,202

5,559 5,632 5,973

6,308 (feet) – 33 – 64 – 107 – 355 – 100

– 88 – 93 – 89

– 354 Mean 5,160 5·016 – 143

K.

ACTINOMETER OBSERVATIONS.

The few actinometer observations which I was enabled to record, were made with two of these instruments constructed by Barrow, and had the bulbs of their thermometers plunged into the fluid of the chamber. They were taken with the greatest care, in conformity with all the rules laid down in the “Admiralty Guide,” and may, I think, be depended upon. In the Sikkim Himalaya, a cloudless day, and one admitting of more than a few hours’ consecutive observations, never occurs—a day fit for any observation at all is very, rare indeed. I may mention here that a small stock of ammonia-sulphate of copper in crystals should be supplied with this instrument, also a wire and brush for cleaning, and a bottle with liquid ammonia: all of which might be packed in the box.

Active 6.568. Time always mean.

_Jillapahar, Dorjiling, Elev. 7,430 feet, Lat. 27° 3′ N., Long. 88° 13′ E._ A.—APRIL 19TH, 1850. _Watch slow 1′ 15″ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 8.00 to 8.13 a.m. 8.15 to 8.28 a.m. 9.00 to 9.13 a.m. 10.00 to 10.13 a.m. 11.00 to 11.13 a.m. Noon to 12.13 p.m. 1.00 to 1.13 p.m. 2.00 to 2.13 p.m. 11·1 15·0 17·7 19·1 19·0 18·8 17·2 17·4 65·5 69·5 71·5 72·5 75·0 75·0 73·3 74·0 9·9900 12·2645 14·5140 15·4710 14·9150 12·7600 13·8976 13·8330 22·960

22·948 22·947 22·946 22·944 22·939 22·914 53·5

56·0 57·0 58·5 60·3 59·4 60·3 33·8

37·2 39·7 38·2 44·8 40·7 44·1 19·7

18·8 17·3 20·3 15·5 18·7 16·2 ·505

·513 ·550 ·500 ·592 ·546 ·577 88·0 111·5 110·0 121·0 125·0 120·0 122·0 108·0 Day unexceptional, wind S.W., after 10 a.m. squally.

Dense haze over snowy mountains.

B.—APRIL 20TH.

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 8.0 to 8.30 a.m. 9.0 to 9.13 a.m. 10.0 to 10.13 a.m. 11·8 17·8 18·8 64·0 73·3 65·0 10·9150 14·2750 14·7580 22·969 22·974 22·985 54·2 56·2 57·0 43·4 44·1 42·5 10·8 12·1 14·5 ·691 ·662 ·609 74·0 92·0 92·0 Dense haze, S.E. wind, cloudless sky.

_Superintendent’s House, Dorjiling, Elev. 6,932 feet._ C.—APRIL 21ST. _Watch slow 1′ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 8.35 to 8.48 a.m. 9.07 to 9.20 a.m. 10.00 to 10.13 a.m. 11.00 to 11.13 a.m. 17·3 20·9 23·9 24·4 65·0 72·7 77·3 81·0 15·7084 16·8872 18·3791 17·8864 23·447 56·4 63·8 60·8 47·6 49·9 49·2 8·8 13·9 11·6 ·741 ·628 ·677 97.0 100·0 109·0 107·5 Day very fine, snowy mts. in dull red haze, wind S.E. faint.

_Rampore Bauleah (Ganges). Elev. 130 feet, Lat. 24° 24′ N., Long. 88° 40′ E._ MAY 17TH, 1850. _Watch slow 15″ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 7.51 to 8.13 a.m. 9.03 to 9.17 a.m. 9.20 to 9.33 a.m. 11.15 to 11.28 a.m. 11.32 to 11.45 a.m. 1.20 to 1.33 p.m. 1.40 to 1.53 p.m. 13·0 19·5 21·2 21·1 16·5 21·6 21·4 88·0 96·0 107·0 105·0 108·7 108·5 113·7 8·8790 12·5190 12·7836 12·8499 9·8770 12·9348 12·4976 29·698

29·615

29·620 87·5 92·0 92·3 98·5 98·3 104·5 105·8 80·1 81·2 80·2 74·8 74·3 76·7 72·2 7·4 10·8 12·1 23·7 24·0 27·8 33·6 ·793 ·715 ·687 ·478 ·475 ·425 ·355 91·0 83·8 132·0 98·5 142·0 144·0 134·0 S.E. wind, very hazy to west, sky pale blue. Wind west, rising.

_Churra, Khasia Mountains. Elev. 4,225 feet, Lat. 25° 15′ N., Long. 91° 47′ E._ A.—NOVEMBER 4TH, 1850. _Watch slow 7′ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 6.20 to 6.30 a.m. 6.32 to 6.42 a.m. 7.55 to 8.05 a.m. 8.08 to 8.18 a.m. 8.20 to 8.30 a.m. 5·0 7·4 20·0 21·0 24·2 63·7 65·4 77·5 82·0 85·8 4·6400 6·6896 15·2400 15·2040 16·8432 25·781 57·8 59·0 63·5 64·4 64·8 53·1 54·8 56·9 57·3 59·5 4·7 4·2 6·6 7·1 5·3 ·850 ·870 ·806 ·790 ·837 75·0 83·0 108·0 106·5 113·5 Sky faint blue, cloudless, wind S.W., clouding.

B.—NOVEMBER 5TH. _Watch slow 7′ mean time._

Hour Act. Temp. Act. Act. reduced Air D.P. Diff. Sat. Black Bulb 6.39 to 6.49 a.m. 6.51 to 7.01 a.m. 7.56 to 8.06 a.m. 8.08 to 8.21 a.m. 9.26 to 9.36 a.m. 9.37 to 9.47 a.m. 10.57 to 11.07 a.m. 11·2 13·4 18·4 20·4 23·8 25·1 29·0 70·2 72·8 73·2 77·7 79·5 84·0 89·5 9·3408 10·8138 15·0161 15·4836 17·8072 17·7959 19·5460 59·4 60·5 61·7 63·3

66·7 57·6 57·8 57·7 58·7

60·8 1·8 2·7 4·0 4·6

5·9 ·940 ·918 ·875 ·860

8·28 126·0 Wind S.W., clouds rise and disperse. Sky pale.

C.—NOVEMBER 6TH. _Watch slow 7′ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 6.05 to 6.18 a.m. 6.22 to 6.35 a.m. 6.38 to 6.51 a.m. 8.27 to 8.37 a.m. 8.39 to 8.52 a.m. 2·6 6·5 9·6 21·7 23·0 62·0 63·5 66·7 78·8 81·7 2·4986 6·0710 8·5152 16·2750 19·4750 25·781 56·5 57·0 61·0 64·2 64·5 54·5 55·1 57·4 59·3 59·4 2·0 1·9 3·6 4·9 5·1 ·935 ·935 ·888 ·855 ·847

100·0 105·0 Sunrise, 6, pale yellow red, cloudless. Cirrhus below.

D.—NOVEMBER 14TH, 1850.

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 6.12 to 6.22 a.m. 6.24 to 6.37 a.m. 7.13 to 7.23 a.m. 7.24 to 7.34 a.m. 8.34 to 8.44 a.m. 8.47 to 9.00 a.m. 9.53 to 10.03 a.m. 10.04 to 10.17 a.m. 11.24 to 11.31 a.m. 2·9 6·1 12·4 14·7 19·9 21·7 23·5 25·3 33·3 60·6 66·0 70·8 76·0 82·8 88·8 86·6 89·5 111·5 3·5988 5·4472 10·2672 11·4025 14·2653 14·7343 16·2620 17·0775 20·7014 25·783

25·832

25·819 51·5 52·7 56·5 57·8 59·8 60·5 67·2 67·0 64·6 49·4 50·3 52·3 53·1 50·8 51·6 61·6 58·8 59·0 2·1 2·4 4·2 4·7 9·0 8·9 5·6 8·2 5·6 ·930 ·925 ·900 ·855 ·742 ·730 ·832 ·778 ·832

98·0 104·0 117·0 121·0 127·0 133·0 130·0

Thick cumulus low on plains. Sunrise yellow red. Cloudless.

Clouds rise.

E.—NOVEMBER 15TH, 1850.

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. 9.53 to 10.06 a.m. 10.50 to 11.03 a.m. 11.31 to 11.44 a.m. 12.33 to 12.46 p.m. 1.07 to 1.21 p.m. 2.47 to 3.00 p.m. 3.48 to 4.00 p.m. 4.03 to 4.16 p.m. 25·8 26·1 28·5 30·9 29·1 21·1 16·7 16·2 78·0 80·5 84·0 91·5 90·5 75·0 73·0 75·0 17·5306 19·1835 20·2065 20·4267 20·4388 16·5635 13·4435 12·7170 25·854

25·844

25·808

25·803 63·0 64·0 65·3 65·8 67·0 67·2 62·0 61·5 55·3 52·8 51·9 51·2 49·6 56·6 50·8 50·5 8·7 11·2 13·4 14·6 17·4 10·6 11·2 11·0 ·772 ·690 ·638 ·620 ·560 ·708 ·690 ·692 Sky cloudless. Wind N.E.

_Silchar (Cachar). Elev. 116 feet, Lat. 24° 30′ N., Long. 93° E. (approximate)_ NOVEMBER 26TH, 1850. _Watch slow 13′ 39″ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. 9.11 to 9.24 a.m. 9.34 to 9.41 a.m. 9.50 to 9.57 a.m. 10.07 to 10.14 a.m. 11.03 to 11.16 a.m. Noon to 12.03 p.m. 12.58 to 1.11 p.m. 2.51 to 3.04 p.m. 3.55 to 4.08 p.m. 4.09 to 4.22 p.m. 4.23 to 4.36 p.m. 19·4 22·7 25·3 26·5 26·3 26·4 27·6 23·0 17·6 15·5 12·0 69·0 81·0 87·5 91·5 89·0 90·0 94·0 93·0 91·5 93·5 93·7 16·4706 16·5937 17·3558 17·5695 17·5251 17·8144 17·9676 15·0880 11·6688 11·0215 7·8360

29·999

29·967

29·892

29·881 66·3

68·7 70·3 73·2 74·5 76·8 78·5 79·5 79·4 78·5 63·5

61·5 62·7 60·3 61·7 60·3 62·1 57·0 62·1 62·1 2·8

7·2 7·6 12·9 12·8 16·5 16·4 22·5 17·3 16·4 ·860

·788 ·780 ·657 ·658 ·586 ·588 ·480 ·570 ·588 Dense fog till 7.30 a.m. Wind north. Clear.

Wind N.E. Light cirrhus low.

Streaks of cirrhus aloft.

Sun sets in hazy cirrhus.

_Chittagong, Elev. 200 feet, Lat. 22° 20′ N., Long. 91° 55′ E._ A.—DECEMBER 31ST, 1850. _Watch slow 3′ 45″ mean time._

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 7.39 to 7.52 a.m. 8.40 to 8.53 a.m. 9.04 to 9.08 a.m. 9.52 to 9.56 a.m. 10.02 to 10.06 a.m. 11.16 to 11.29 a.m. 11.52 to 11.56 a.m. 1.38 to 1.41 p.m. 1.47 to 1.51 p.m. 3.10 to 3.17 p.m. 3.18 to 3.25 p.m. 10·0 21·3 23·2 24·3 25·1 24·3 26·6 24·7 25·4 21·1 19·3 70·0 91·5 89·5 87·3 90·5 84·5 92·6 84·0 90·7 86·0 89·3 8·3700 14·1219 15·6136 16·7341 16·7668 17·1558 17·5028 17·5123 16·8418 14·6645 13·0468 29·874

29·923

29·892

29·831 57·0 59·5 63·3 64·5 65·7 68·5 69·5 71·7

71·0 55·7 57·2 59·7 61·3 60·4 58·6 59·2 61·8

60·5 1·3 2·3 3·6 3·2 5·3 9·9 10·3 9·9

10·5 ·960 ·920 ·890 ·900 ·840 ·722 ·710 ·720

·710 127·0

142·0 148·0 150·0 Cloudless. Mountains clear. Wind N.N.E. Cool. Wind N.W.

Wind S.W.

Clouds about in patches.

B.—JANUARY 1, 1851. Watch slow 3′ 45″ mean time.

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 7.34 to 7.41 a.m. 8.38 to 8.45 a.m. 9.44 to 9.51 a.m. 10.46 to 10.53 a.m. 11.50 to 11.57 a.m. 12.06 to 12.13 p.m. 12.58 to 1.02 p.m. 1.45 to 1.52 p.m. 3.15 to 3.22 p.m. 4.27 to 4.34 p.m. 4.36 to 4.43 p.m. 4.45 to 4.52 p.m. 4.56 to 5.09 p.m. 5.12 to 5.18 p.m. 10·0 16·0 19·5 21·0 21·5 24·1 23·9 21·4 18·1 10·2 9·8 8·5 5·6 3·8 69·4 70·0 74·7 78·2 81·2 88·0 87·2 84·5 82·5 82·0 84·0 85·0 85·0 84·0 8·4200 13·3920 15·3660 15·8550 15·6950 16·4603 16·4432 15·0870 13·0320 7·3746 6·9482 5·9670 3·9312 2·6942 29·948

29·891

29·850

29·798

29·778 55·4 58·9 63·2 66·7 69·8 70·3 71·0 71·3 71·3 70·0

67·5 68·7 54·0 57·7 61·7 62·4 58·3 56·0 56·7 57·5 57·1 59·5

62·7 62·2 1·4 1·2 1·5 4·3 11·5 14·3 14·3 13·8 14·2 10·5

4·8 6·5 ·953 ·970 ·960 ·870 ·688 ·625 ·625 ·633 ·625 ·708

·855 ·810

104·5 115·0 120·0 117·0 122·5

117·0 Mist rises and drifts westward till 7.30 a.m.

Wind N.W., clouds rise.

Sunset cloudless.

C.—JANUARY 2, 1851. Watch slow 3′ mean time.

Hour Act. Temp. Act. Act. reduced Barom. Air D.P. Diff. Sat. Black Bulb 10.02 to 10.09 10.20 to 10.24 12.03 to 12.10 p.m. 12.22 to 12.25 p.m. 2.04 to 2.08 p.m. 2.10 to 2.14 p.m. 19·2 22·6 24·7 25·9 23·3 23·8 71·0 79·0 89·2 95·5 91·5 93·0 15·8592 16·9048 16·6972 18·6796 15·4479 15·6128 29·861 29·858 64·5 65·6 69·0 70·7 71·2 60·6 61·4 59·3 57·5 61·0 3·9 4·2 9·7 3·2 10·2 ·878 ·872 ·728 ·650 ·718 116·0

119·0

112·0 Low, dense fog at sunrise, clear at 9 a.m. Hills hazy and horizon grey.

L.

TABLE OF ELEVATIONS.

In the following tables I have given the elevations of 300 places, chiefly computed from barometric data. For the computations such observations alone were selected as were comparable with contemporaneous ones taken at the Calcutta Observatory, or as could, by interpolation, be reduced to these, with considerable accuracy: the Calcutta temperatures have been assumed as those of the level of the sea, and eighteen feet have been added for the height of the Calcutta Observatory above the sea. I have introduced two standards of comparison where attainable; namely, 1. A few trigonometrical data, chiefly of positions around Dorjiling, measured by Lieutenant-Colonel Waugh, the Surveyor-General, also a few measured by Mr. Muller and myself, in which we can put full confidence: and, 2. A number of elevations in Sikkim and East Nepal, computed by simultaneous barometer observations, taken by Mr. Muller at Dorjiling. As the Dorjiling barometer was in bad repair, I do not place so much confidence in these comparisons as in those with Calcutta. The coincidence, however, between the mean of all the elevations computed by each method is very remarkable; the difference amounting to only thirty feet in ninety-three elevations; the excess being in favour of those worked by Dorjiling. As the Dorjiling observations were generally taken at night, or early in the morning, when the temperature is below the mean of the day, this excess in the resulting elevations would appear to prove, that the temperature correction derived from assuming the Calcutta observations to correspond with eighteen feet above the level of the sea at Sikkim, has not practically given rise to much error.

I have not added the boiling-point observations, which afford a further means of testing the accuracy of the barometric computations; and which will be found in section J of this Appendix.

The elevation of Jillapahar is given as computed by observations taken in different months, and at different hours of the day; from which there will be seen, that owing to the low temperature of sunrise in the one case, and of January and October in the others, the result for these times is always lowest.

Most of the computations have been made by means of Oltmann’s tables, as drawn up by Lieutenant-Colonel Boileau, and printed at the Magnetic Observatory, Simla; very many were worked also by Bessell’s tables in Taylor’s “Scientific Memoirs,” which, however, I found to give rather too high a result on the averages; and I have therefore rejected most of them, except in cases of great elevation and of remarkable humidity or dryness, when the mean saturation point is an element that should not be disregarded in the computation. To these the letter B is prefixed. By far the majority of these elevations are not capable of verification within a few feet; many of them being of villages, which occupy several hundred feet of a hill slope: in such cases the introduction of the refinement of the humidity correction was not worth the while.

SERIES I.—_Elevations on the Grand Trunk-road. February, 1848._

No. of Obs. Name of Locality Elevation Feet 1 2 3 2 4 1 2 1 1 1 1 4 1 3 1 3 3 1 1 2 4 1 3 4 4 Burdwan Gyra Fitcoree Tofe Choney Maddaobung Paras-nath saddle Paras-nath cast peak Paras-nath flagstaff Paras-nath lower limit of _Clematis_ and _Berberis_ Doomree Highest point on grand trunk-road Belcuppee Hill 236th mile-stone Burree Hill 243rd mile-stone Chorparun Dunwah Bahra 284th mile-stone Sheergotty Muddunpore 312th mile-stone Naurungabad Baroon (on Soane) Dearee (on Soane) 93 630 860 912 1230 B.4231 4215 4428 3162 996 1446 1219 1361 1169 1339 1322 625 479 474 460 402 365 337 344 332

SERIES II.—_Elevations in the Soane Valley. March, 1848._

No. of Obs. Name of Locality Elevation Feet 3 6 2 4 3 6 4 1 3 1 9 4 4 4 7 Tilotho Akbarpore Rotas palace Tura Soane-pore Kosdera Panchadurma Bed of Soane above Panchadurma Pepura Bed of Soane river Chahnchee Hirrah Kotah Kunch Sulkun 395 403 1489 453 462 445 492 482 587 400 499 531 541 561 684

SERIES III.—_Elevations on the Kymore Hills. March, 1848._

No. of Obs. Name of Locality Elevation Feet 2 9 1 1 9 Roump Shahgunj Amoee Goorawul Mirzapore (on the Ganges) 1090 1102 818 905 362

SERIES IV.—_Elevations near Dorjiling. 1848 to 1850._

Number of Obs. Name of Locality Elevation Feet

9 110 104 99 93 37 ———— Sum 452 =======

27 84 37 7 83 74 95 18 ———— Sum 434 =======

103

16

38 25

2 2 7

1 12 2 5 8

4 4 1 13 13 2 2

13 1 4

8 Jillapahar (Mr. Hodgson’s house) sunrise 9.50 p.m. noon 2.40 p.m. 4 p.m. sunset

_Ditto by Monthly observations._ January February March April July August September October

The Dale (Mr. Muller’s) by trigonometry Superintendent’s house by trigonometry Colinton (Mr. Muller’s) Leebong by trigonometry Summit of Jillapahar Smith’s hotel Monastery hill below the Dale The Dale by barometer

Monastery hill by trigonometry

Ging (measured from Dale) Guard-house at Great Rungeet Bed of Great Rungeet at cane-bridge Guard-house at Little Rungeet Sinchul top by trigonometry Saddle of road over shoulder of Sinchul Senadah (Pacheem) bungalow Pacheem village Kursiong bungalow Punkabaree Rungniok village Tonglo, summit by trigonometry Tonglo, Saddle below summit Tonglo, Rocks on ascent of Sourse of Balasun Source of Balasun by Dorjiling Goong ridge

7301 7443 7457 7477 7447 7447 ————— Mean 7429 =========

7400 7445 7517 7582 7412 7421 7454 7351 ————— Mean 7448 =========

B. 6957 6952 B. 6932 6932 B. 7179 B. 5993 [435]6021 B. 7896 6872 B. 214·1 6952 ————— 7166 7165·3 =========

B. 5156 B. 1864 818 1672 8655 8607 7412 7258 3855 B. 4813 1815 B. 4565 B. 10·078 10·079·4 B. 10·008 B. 8148 7436 7451 7441

[435] To summit of chimney, which may be assumed to be 30 feet above where the barometer was hung.

SERIES V.—_Elevations in East Nepal, October to December, 1848._

Number of Obs. Name of Locality By Calcutta Barom. By Dorjiling Barom.

1 7 7 5 2 1 3 8 3 5 4 4 3 1 3 3 3 1 3 2 8 3 3 3 2 2 10 6 1 1 4 2 2 9 1 1 4 1 3 1 2 1 4 1 4 3 1 8 1 3 4 7 2 4 1

Source of Myong river Myong valley, camp in Myong valley Purmiokzong Shoulder of Nanki Shepherd’s huts on do. Summit of Nanki Camp on Nanki Jummanoo Sulloobong Bheti village Sakkiazong village Camp on ridge of mountain Peak on Sakkiazong Makarumbi Pemmi river Tambur river at junction with Pemmi Camp on Tambur, Nov. 13 Camp on Tambur, Nov. 14 Chintam village Mywa Guola Tambur river, Nov. 18 Tambur river, Nov. 19 Taptiatok village Loontoong village Tambur river, Nov. 23 Wallanchoon village Tuquoroma Wallanchoon pass Foot of pass-road Yangma Guola Base of great moraine Top of moraine above ditto Yangma village camp Lake bed in valley Upper ditto (Pabuk) Yangma valley camp, Dec. 2 Kambachen pass Camp below ditto Kambachen village Camp in valley Choonjerma pass Camp below ditto Yalloong river-terrace Camp side of valley Yankutang village Saddle of road south of Khabili Khabang village Spur of Sidingbah, crossed Nov. 10 Yangyading village Sablakoo Iwa river, Dec. 12 Iwa river, Dec. 13 Singaleh, camp on Islumbo pass (feet) 4,798 4,345 3,801 4,507 7,216 8,999 9,994 9,315 4,320 5,244 4,683 5,804 8,315 9,356 5,444 2,149 1,289 1,418 1,600 3,404 2,079 2,515 3,113 4,207 5,615 8,066 10,384 12,889 B. 16,764 13,501 9,236 12,098 B. 679 B. 13,516 15,186 B. 16,038 10,997 B. 15,770 11,643 11,378 11,454 B. 15,259 13,289 10,449 10,080 5,530 5,746 5,495 6,057 4,082 4,735 3,747 6,134 9,263 10,388 (feet)

4,345 3,763 4,535

10,045 9,324 4,404 5,311

5,847 8,391 9,289 5,525 2,262 1,487 1,496

2,185 2,574 3,289 4,359 5,738 8,096 10,389 12,999 16,748 13,518 9,322 12,199

13,488

11,001

11,611

11,514

13,287

10,035 5,598

5,515 5,980 4,145 4,718 3,818 6,184 9,328

Number of Obs. Name of Locality By Calcutta Barom. By Dorjiling Barom.

4 6 5 6 6 7 8 1 1 6 1

5 1 1 10 9 1 9 1 22 7 15 7 21 1 1 1 1 4 5 5 5 1 6

Kulhait valley, camp in Lingcham village Bed of Great Rungeet, December 20 Lingdam village, December 21 Nampok village Bhomsong Mainom top Neon-gong Goompa Pass from Teesta to Rungeet Lingdam village Great Rungeet below Tassiding Tassiding temples Sunnook, camp on Bed of Ratong Pemiongchi temple Camp at Pemiongchi village Tchonpong village Bed of Rungbi river Camp on Ratong river Doobdi Goompa Yoksun Dumpook Buckim Mon Lepcha top Jongri Ratong below Mon Lepcha Ratong below Yoksun Catsuperri lake Catsuperri temple Tengling village Rungbee river bed Changachelling temple Kulhait river Saddle of Hee hill Camp on Hee hill (feet) 6,406 4,892 1,805 5,552 4,354 1,556 Tr. 10,702 5,225 6,824 5,349 2,030 4,840 3,955 2,481 7,083 6,551 4,952 3,165 3,100 6,493 5,600 6,646 8,625 13,090 B. 13,170 7,069 3,729 6,068 6,493 5,295 3,230 6,805 3,075 7,289 6,609 (feet) 6,374 4,848 1,874 5,556 4,501 1,533 B. 10,613

5,401

4,018

6,616 5,003

3,242 6,451 5,635 6,710 8,693 13,045 13,184 7,217 3,851 6,009 6,476 5,219 3,350 6,850 3,243

6,744

SERIES VII.—_Elevations in the Sikkim Terai and Plains of India, Gangetic Delta and Jheels._

Number of Obs. Name of Locality Elevation Feet 3 12 3 4 4 4 5 5 5 1 6 43 24 12 13 54 33 13 4 3 5 Siligoree Bungalow Titalya Sahibgunj (west of Titalya) Bhatgong Thakya-gunj Bhojepore Rummai Rangamally Belakoba Mela-meli Kishengunj Mahanuddy river between Kishengunj and Maldah Mahanuddy river between Maldah and Rampore Bauleah Rampore (Mr. Bell’s) Dacca (Mr. Atherton’s) Jheels, Dacca to Pundua Megna river (June 1st-6th Soormah (June 9th) Pundua (June 10th and 11th) Pundua (Sept. 7th) Pundua (Nov. 16th and 17th) 302 326 231 225 284 404 293 262 368 337 131 153 98 130 72 *– ·003 + ·008 + ·048 + ·018 – ·016 – 0·66

* The observations marked thus * are the differences in inches between the readings of my barometer at the station, and that at the Calcutta observatory, which is 18 feet above the sea-level.

SERIES VIII.—_Elevations in Sikkim, May to December, 1849._

Number of Obs. Name of Locality By Calcutta Barom. By Dorjiling Barom.

2 4 1 2 4 8 4 4 2 8 10 16

Mik, on Tendong Namtchi, camp on spur Tendong summit Temi, Teesta valley Nampok, Teesta valley Lingmo, Teesta valley Lingtam spur, Teesta valley Gorh, Teesta valley Bling-bong, Teesta valley Lingo village, Teesta valley Singtam, May 14 to 16 Singtam (higher on hill) Oct. 30 to Nov. 2 (feet) 3,912 5,608 B. 8,671 4,771 B. 5,138 B. 2,861 B. 4,743 B. 4,061 B. 2,657 B. 2,724 B. 4,435 B. 4,575 (feet)

Tr. 8,663

5,033 2,838 4,867 4,195 2,711 2,839 4,477

SERIES VIII.—_(Continued)_

Number of Obs. Name of Locality By Calcutta Barom. By Dorjiling Barom.

5 2 7 27 37 4 4 3 8 1 1 33 53 1 4 74 47 1 1 2 43 20 30 1 3 2 5 2 6 2 2 56

1 1 1 1 1 1

Niong Namgah Chakoong Choongtam, May Choongtam, August Dholep, Lachen Dengha, Lachen Latong, Lachen Kampo Samdong Chateng Chateng, lower on spur Lamteng village Zemu Samdong Snow bed across Zemu river Camp on banks of Zemu Junction of Thlonok and Zemu Camp on banks of Zemu river Zemu river, June 13 Zemu river, high up, June 13 Yeunga (Lachen valley) Tallum Samdong Tungu, July Tungu, October Palung plains Sitong Kongra Lama pass Yeumtso (in Tibet) Bhomtso (in Tibet) Cholamoo lakes (in Tibet) Donkia pass, October Donkia pass, September Momay Samdong

Donkia, September 13 Kinchinjhow, September 14 Sebolah pass South shoulder of Donkia, September 20 Mountain north of Momay, September 17 West shoulder of Donkia mountain, September 26

_The following were measured trigonometrically:_ Forked onkia mountain Kinchinjhow mountain Tomo-chamo, east top of Kinchinjhow Thlonok mount, Peak on Chango-khang mountain Tukcham mountain, from Dorjiling Chomiomo mountain (feet)

4,229 4,371 5,245 5,247 6,120 6,337 6,471 7,315 8,819 8,493 8,900 9,026 9,828 10,223 10,864 12,064 12,422 13,281 10,196 11,540 12,779 12,799 15,697 15,372 15,745 16,808 18,590 16,900 18,589 18,387 15,362

16,876 17,495 17,604 18,257 (feet) 3,954

4,443 5,284 5,297 6,145 6,399 6,310 7,344 8,695 8,343 8,867 8,926

10,271 10,828 12,074

11,424 12,723 12,747

15,642

15,069 Measured from Momay 17,079 17,656 17,567 18,357 B. 17,394 B. 18,510

Tr. 20,870 Tr. 22,750 Tr. 21,000 Tr. 20,000 Tr. 20,600 Tr. 19,472 Tr. 22,700

SERIES VIII.—_(Continued)_

Number of Obs. Name of Locality By Calcutta Barom. Measured by Trig., etc.

48 7

2 3

51 12 8 2 3 4 3 5 7 1 3 1 3 17 3 105 1 2 3 12 11 2 3 5 6 _The following were measured trigonometrically:_ Summit of Donkia (from Donkia pass and Bhomtso) Tunkra Mountain, from Dorjiling

Yeumtong Yeumtong, October

Snow bed above Yeumtong Punying

Lachoong village, August Lachoong village, October Lacheepia Tunkra pass Rock on ascent to ditto Keadom Tukcham village Rinkpo village Laghep Phieungoong Barfonchen Chola pass Chumanako Phadong Tumloong, Nov. 3rd and 4th Higher on hill, Nov. 16th to Dec. 9th Yankoong Tikbotang Camp, Dec. 11th Serriomsa Dikkeeling Singdong Katong ghat, Teesta Namten Cheadam (feet)

11,933 11,951

B. 15,971 B. 11,299

B. 8,712 B. 8,705 B. 15,293 B. 16,083 B. 13,078 B. 6,609 B. 3,849 B. 6,008 B. 10,423 B. 12,422 B. 11,233 B. 14,925 B. 12,590 B. 5,946 B. 5,368 B. 5,976 B. 3,867 B. 3,763 B. 2,952 B. 2,820 B. 4,952 B. 2,116 B. 735 B. 4,483 B. 4,653 (feet) Tr. 22,650 Tr. 18,250 By Dorjiling Barometer 11,839

By Yeumtong Barometer 16,000

By Der. Bar. 8,474

15,231

13,144

SERIES IX.—_Khasia Mountains, June to November, 1850._

Number of Obs. Name of Locality Elevation Feet 36 167 102 25 63 1 9 1 32 6 9 63 6 10 35 12 9 3 Churra (Mr. Inglis’s) Churra bungalow opposite church, August Churra bungalow, Oct., Nov. Kala-panee bungalow Moflong bungalow Chillong hill Syong bungalow Hill south of ditto Myrung bungalow, July Myrung bungalow, Sept. Chela Nunklow Nonkreem Mooshye Pomrang Amwee Joowye Nurtiung 4,069 4,193 4,258 5,302 6,062 6,662 5,725 6,050 5,647 5,709 80 4,688 5,601 4,863 5,143 4,105 4,387 4,178

SERIES X.—_Soormah, Silhet, Megna, Chittagong, etc._

Number of Obs. Name of Locality Elevation Feet 27 38 36 24 12 10 72 8 2 16 3 12 4 17 10 Silhet (Mr. Stainforth’s) Soormah river, between Silhet and Megna Silchar Megna river Noacolly (Dr. Baker’s) Noacolly on voyage to Chittagong Chittagong (Mr. Sconce’s) Chittagong flagstaff-hill at south head of harbour Seetakoond hill Seetakoond bungalow Hat-Hazaree Hattiah Sidhee Chittagong to Megua Eastern Sunderbunds 133 46 116 + ·020* – ·039 0† 191 151 1,136 – ·069* – ·039 – ·049 – ·039 – ·014† + ·002

* Difference between barometer at station and Calcutta barometer.

† The observations were taken only when the boat was high and dry, and above the mean level of the waters.

INDEX

A

_Abies, Brunoniana,_ i. 206, 209, 272, 274, 342, ii. 25, 32, 44, 108; _Smithiana,_ ii. 25, 32, 45; _Webbiana,_ i. 191, 272, 307, 342, ii. 44, 108. _Abrus precatorius_ (note), i. 16. _Acacia Arabica,_ i. 60, 80; _Catechu,_ i. 31, 52, 393, 395; _Serissa,_ i. 193. _Acarus,_ ii. 173. _Aconitum,_ Himalayan, ii. 108; _palmatum,_ i. 168; _Napellus,_ i. 168; _variegatum_ (note), ii. 107. Acorns, abundance of, i. 373. _Acorus Calamusa,_ i. 286. Actinolites, ii. 146. _Adamia cyanea,_ i. 112. _Adenanthera pavonina,_ ii. 328. _Ægle Marmelos,_ i. 25, 50, (note) i. 16. Agates, i. 33, 91. _Ailurua ochraceus,_ ii. 108. Akshobya, image of, i. 322. Alligator, i. 51, 54; droppings of in river banks, ii. 251. Alluvium, Gangetic, i. 88, 379. _Alsophila gigantea,_ i. 110, 142; (note), ii. 13; _spinulosa_ (note), ii. 13. Amber used in Sikkim, ii. 194. _Ameletia Indica,_ i. 386. American plants in Himalaya, ii. 39. _Amherstia,_ ii. 245. Amlah, Sikkim, ii. 192; examination by, ii. 211. Amulet, Tibetan, i. 166. Amwee, ii. 315. _Andromeda,_ ii. 22, 39; _fastigiata,_ i. 343. _Andropogon acicularis,_ i. 385; _muricatus,_ i. 42. Animals at Tungu, ii. 92. Antelope, ii. 132. _Antilope Hodgsoni,_ ii. 157. Ants’ hills, white, i. 20. _Aponogeton,_ i. 62. Apoplexy, symptoms of at great elevations, ii. 178. Apple, crab, ii. 32; wild, i. 205; ii. 148. _Aquilaria Agallocha,_ ii. 328. _Aralia_ used for fodder, i. 359; pith yielding rice-paper, i. 359. Ararat, Mount, ii. 3. _Areca gracilis,_ ii. 10; (note) i. 143. _Arenaria rupifraga,_ ii. 89. _Argemone Mexicana,_ i. 30. _Arisœma,_ i. 49. _Aristolochia saccata,_ ii. 6. Arrat, name of Lepchas, i. 127. Arrow-root, i. 93. _Artemisia,_ headache produced by, ii. 20; _Indica_ (note), ii. 20. Arums, food prepared from, ii. 49; poisoning by, ii. 75. Arun river, i. 224; ii. 124, 143; sources of, ii. 167. _Asarum,_ ii. 48. Assam valley, view of, ii. 290. Ass, wild, ii. 172. (See _Equus Hemionus_ and Kiang). _Astragalus,_ used for making paper, ii. 162; Tibetan (note), ii. 165. Atmosphere, dry, i. 65; transparency of, ii. 127, 169. Atmospheric vapours, strata of, i. 188, 310. Attar of roses, i. 78. _Aucuba,_ i. 126; ii. 39. Aurora Borealis, i. 37; Appendix, 384.

B

Baghoda, i. 26. Baikant-pore, i. 393. Bails, or Thuggee stations, i. 68. Baisarbatti terrace, i. 401. Baker, Dr., ii. 339. Balanites, i. 25. _Balanophora,_ ii. 19, 47; cups made from, i. 132; knots caused by, i. 133. Balasun river, i. 110, 402. Bamboo, dwarf, i. 126; eatable grain of, i. 313; flowering of, i. 155, 158; kinds of in Khasia, ii. 268; kinds and uses of in Sikkim, i. 155, 158; planted, i. 386. _Bambusa stricta,_ i. 30. Bananas, wild, i. 20, 143; scarlet-fruited, ii. 319. Ban, or Lepcha knife, i. 130. Banyan tree, i. 18; of Calcutta gardens, ii. 246. Barnes, Mr., i. 95; Mr. Charles, i. 114. Barometer, accident to, ii. 139; observations on Jheela, ii, 258. Baroon on Soane river, i. 35. _Bassia butyracea,_ i. 151; _latifolia,_ i. 16. Bath, hot, at Bhomsong, i. 305; at Momay, ii. 133; at Yeumtong, ii. 117. Beadle, Lieut., i. 26. _Beaumontia,_ i. 401. Bee, alpine, ii. 68; boring, i. 374; leaf-cutting, i. 46. Beejaghur, i. 56. Bees’-nests, i. 201; ii. 16. _Begonia,_ alpine, ii. 108. Behar, hills of, i. 32. Belcuppee, i. 28. Bellows, Himalayan, ii. 82; of Khasia, ii. 310; of leaves, i. 53. Benares, i. 71; observatory at, i. 74. _Berberis Asiatica_ (note), i. 24; _concinna,_ ii. 198; _insignis,_ i. 364. Betel-pepper, i. 99; ii. 327. Bhaugulpore, i. 90; gardens at, i. 91. Bhel fruit, i. 50. Bhomsong, i. 297; ii. 8; temperature of soil at, i. 305. Bhomtso, ii. 124, 164, 174; elevation, temperature etc., at, ii. 175. Bhotan, called Dhurma country (note), i. 136; 366 (note). Bhotanese (note), i. 136; ii. 232. Bhotan Himalaya, i. 153; ii. 165, 298. Bhoteeas, i. 205, 215. Bhote (note), i. 136. _Bignonia Indicta,_ i. 16. Bijooas, or Lepcha priests, i. 135. Bikh poison, i. 168; ii. 108. Bind hills, i. 64. Birds at Momay, ii. 131; of Khasia, ii. 305; of Terai, i. 399. Black-rock of Colonel Waugh (note), ii. 18. Blocks, granite, ii. 293, 310; split, i. 201; syenite, ii. 303. Boat on Ganges, i. 70. Boga-panee, ii. 287, 308. Bombax, i. 26. Boodhist banners, i. 144; monuments, i. 147; temple, i. 77; worship, i. 174, 324; worship introduced into Sikkim, i. 127. _Borassus,_ i. 39. Bore, or tidal-wave, ii. 343. Bor-panee, ii. 301, 318. _Borrera,_ ii. 165, 173. Borr (_Pandanus),_ i. 300; ii. 9. _Boswellia thurifera,_ i. 29, 39. _Botrichium Virginicum,_ i. 293. Boulders in river-beds, i. 288; of gneiss on Jongri, i. 353; on Mon Lepcha, i. 342. _Bowringia,_ ii. 313. Bread, Tibetan, i. 297. Breccia, modern formation of, i. 200. Bridge, at Amwee, ii. 315; living, ii. 268; of canes, i. 149; ii. 21. _Buceros,_ i. 187. _Buchanania,_ i. 26. _Bucklandia,_ ii. 185. Buckwheat, cultivated at Jigatzi, ii. 171; wild, ii. 31. _Bufo scabra,_ ii. 96. Bugs, flying, i. 81. Burdwan, i. 6; coal-fields, i. 8. Burkutta river, i. 28. Burrampooter, altered course of, ii. 253, 346; old bed of, ii. 256; Tibetan, _see_ Yaru-tsampu; view of from Khasia, ii. 300, 301. _Butea frondosa,_ i. 9, 52, 381, 392. Butter, churning, ii. 77, 87; ornaments made of, ii. 88. Butterflies, painted lady, ii. 33; at various elevations, ii. 26, 65, 98, 132; tropical, i. 152.

C

Cachar, ii. 326; rain-fall at, ii. 334. _Cœsalpinia paniculata,_ i. 25. Cajana, i. 13. _Calami,_ species of in Himalaya, i. 143. _Calamus,_ ii. 10. Calcutta, journey to, ii. 242. _Callitriche verna?_ (note), ii. 96. _Calotropis,_ i. 30, 86; _C. arborea,_ i. 72; temperature of, i. 36. _Caltha palustris_ (note), ii. 77; _scaposa_ (note), ii. 77. Camels, i. 61; at Lhassa, ii. 172. Campbell, Dr., joins me in Terai, i. 376; meet at Bhomsong, i. 297; at Choongtam, ii. 146; seizure of, ii. 202; sent as Superintendent of Dorjiling, i. 117; treatment of as prisoner, ii. 205. Cane bridge at Choongtam, ii. 21; at Lachoong, ii. 101; over Great Rungeet, i. 149. Canoes of Teesta, i. 392, 396; of Tambur, i. 194; swamped, ii. 335. _Capparis acuminata,_ i. 38. _Cardamine hirsuta,_ i. 230. _Cardiopteris,_ ii. 334. _Carex Moorcroftii,_ ii. 155. _Carissa carandas,_ i. 14, 31. Carroway, ii. 66. _Carthancus,_ i. 80. _Caryota urens,_ i. 143. Cascades of Khasia, ii. 270; of Mamloo, ii. 278. _Cassia fistula,_ i. 393. _Casuarina_ (note), ii. 346. Catechu, collecting, i. 52. _Cathcartia,_ ii. 198. Catsuperri, i. 362; lake, i. 363; temples, i. 365. Cave, Lieut., garden at Churra, ii. 284. _Cedrela Toona,_ i. 144, 193; ii. 18. _Cedrus Libami_ (note), i. 257. Central India, hills of, i. 32. _Cervus Wallichii,_ antlers of, ii. 214. Chachoo river, ii. 84. Chahuchee, i. 51. Chait, description of, i. 324; (note), i. 158. Chakoong, ii. 18, 188. _Chamærops Khasiana,_ ii. 279. Chameleon, i. 205. Changachelling, i. 368. Chango-khang, ii. 84, 133, 141. Chattuc, ii. 262, 309, 337. Chaulmoogra (_See_ Took), i. 151. Cheadam, ii. 234. Cheer-pine, i. 182. Chela, ii. 306. Chepanga, ii. 15. Cherry, alpine wild, ii. 145. Cheytoong, Lepcha boy, ii. 184. Chillong hill, ii. 290. Chinese plants in Khasia, ii. 318; in Sikkim, i. 126; ii. 39. Chingtam, i. 196. Chirring (red rose), ii. 63. Chiru. _See_ Tchiru, ii. 157. Chittagong, ii. 345; leave, ii. 353. Chokli-bi (_Smilacina_), ii. 48. Chola, i. 123; summit of pass, ii. 199; view of from Donkia, ii. 127. Cholamoo lake, ii. 124, 157, 176. Chomachoo river, i. 225; ii. 125. Chomiomo, ii. 80, 94, 165. Choombi, ii. 110. Choongtam, ii. 21, 98, 145, 185; insects at, ii. 98; vegetation of, ii. 24. Choonjerma pass, i. 264. Chumulari, i. 125, 185; ii. 110; discussion on, ii. 166; view of from Khasia, ii. 300. Chunar, i. 71. Chung (Limboos), i. 187. Churra-poonji, ii. 272; rain-fall at, ii. 282; table-land of, ii. 277; temperature of, ii. 284. _Cicada,_ i. 107, 127; ii. 305; upper limit of, ii. 96. _Cicer arietinum,_ i. 80. _Cinnamomum,_ i. 162. Cinnamon of Khasia, ii. 309. _Cirrhopetalum_ (note), ii. 10. Clay of Sikkim, i. 155; Appendix, 383. _Clematis nutans_ (note), i. 24. _Clerodendron,_ i. 387. Climbers, bleeding of, ii. 350; of Sikkim, i. 163. Coal, of Burdwan, i. 8; Churra, ii. 278, 285, 303; Terai, i. 403. Cobra, mountain, ii. 20. _Cochlospermum,_ i. 53. Cocks, Sikkim, i. 314. _Cœlogyne,_ i. 110; _Wallichii,_ i. 166; ii. 311. Coffee, cultivation of, at Chittagong, ii. 347; at Bhaugulpore, i. 93. _Coix,_ cultivation of, ii. 289. Coles, i. 55, 91. Colgong, i. 94. Colvile, Sir J., i. 5. Comb of Lepchas, ii. 194; of Mechis, i. 408. Conch shells, in Boodhist temples, i. 174, 312; cut at Dacca, ii. 254. Conduits of bamboo, i. 144. _Confervæ_ of hot springs, i. 28; Appendix, 375. Conglomerate, ii. 19, 165, 176, 177, 402, 403. _Coniferæ,_ Himalayan, i. 256. _Conocarpus latifolius_ (note), i. 16. Cooch-Behar, i. 384. Cooches, i. 384. Cookies, ii. 330. Corbett, Dr., i. 82. Cornelians, i. 33. Cornwallis, Lord, mausoleum of, i. 78. Corpses, disposal of in Sikkim and Tibet, i. 287. Cosi river, i. 96. Cowage plant, i. 12. Cows, Sikkim, i. 314; ii. 150. Crab, fresh-water, ii. 7. Cranes, i. 392; (note) ii. 161. _Crawfurdia,_ ii. 145. Crows, red-legged, ii. 37. _Cruciferæ,_ rarity of in Himalaya, i. 113. _Cryptogramma crispa,_ i. 262; ii. 68, 72. Crystals in gneiss, ii. 138. _Cupressus funebris,_ i. 315, 317, 336. Cups, Tibetan, i. 132. Currants, wild, i. 148. Currents, ascending, i. 374. Curruckpore hills, i. 87. Cuttack forests, ii. 340. _Cycas pectinata,_ i. 151, 382; ii. 30; (note), i. 143; trees in Calcutta Garden, ii. 247. Cyclops, figure resembling (note), ii. 195. _Cynodon Dactylon,_ i. 385. Cypress funereal, i. 315, 317, 336. _Cypripedium,_ ii. 68, 322.

D

Dacca, ii. 254. Dacoits, i. 65. _Dalbergia Sissoo,_ i. 101. Dallisary river, ii. 256. Damooda valley, i. 7. Dandelion, ii. 66. _Daphne,_ paper from, ii. 162. _See_ Paper. Date-palm, i. 34, 88; dwarf, ii. 300. Datura seed, poisoning by, i. 65. Davis, Mr. C. E., i. 41. _Decaisnea,_ new edible fruit, ii. 198. Deer, barking, i. 399. _Delphinium glaciale,_ i. 269; ii. 95. Demons, exorcisement of, ii. 114. _Dendrobium densiflorum,_ ii. 19; _Farmeri,_ etc., ii. 323; _nobile,_ ii. 19; _Pierardi,_ i. 103. _Dentaria_ (a pot-herb), ii. 47. Denudation of Himalaya, i. 308; of Khasia, ii. 324. Deodar (note), i. 256. Dewan, Sikkim, i. 117; ii. 97; arrival at Tumloong, ii. 217; conferences with, ii. 221, 225; dinner with, ii. 231; disgrace of, ii. 241; hostility to British, i. 117; house of, i. 304. Dhal, i. 13. Dhamersala, i. 222. Dhob grass, i. 385. Dhurma country, name for Bhotan, (note), i. 366; people (note), i. 136; rajah, i. 136; seal of, i. 372. Digarchi, ii. 125. _See_ Jigatzi. Dijong (name of Sikkim), i. 127. _Dilivaria ilicifolia,_ ii. 347. _Dillenia,_ i. 393, 395. Dinapore, i. 82. Dingcham, ii. 87, 169. Dingpun, at Chola, ii. 200, 201; Tibetan, ii. 160; Tinli, ii. 204. _Diospyros embryopteris,_ i. 392; fruit, ii. 64. _Dipterocarpi,_ ii. 345; _D. turbinatus,_ ii. 348. Diseases attributed in Tibet to elements, ii. 178. Djigatzi, ii. 125. _See_ Jigatzi. Dog, loss of, ii. 100; Tibetan, i. 204; wild, i. 43. Do-mani stone, i. 294. Donkia, i. 123; ii. 126; ascent of, ii. 178; forked, ii. 120; pass, ii. 123, 179; temperature of, ii. 129; tops of, ii. 137. Doobdi temples, i. 336. Dookpa, Boodhist sect (note), i. 366. Doomree, i. 25. Dorje, i. 173. Dorjiling, i. 113; ceded to British, i. 116; climate, i. 119, 120; elevation of, i. 115; leave, ii. 248; origin of, i. 115; prospects of, ii. 248; threat of sacking, ii. 214; trade at, i. 118. _Duabanga grandiflora,_ i. 401. Dunkotah (East Nepal), i. 190. Dunwah pass, i. 30. Dust-storm, i. 51, 81. Dye, yellow, ii. 41.

E

Eagle-wood, ii. 328. Earthquake, Chittagong, ii. 349; Noacolly, ii. 342; Titalya, i. 376. _Edgeworthia Gardneri,_ i. 205, 333; ii. 10, 162. Efflorescence of nitrate of lime, i. 43; of soda, i. 13. Eggs of water-fowl in Tibet, ii. 161. Ek-powa Ghat, i. 59. _Elæagnus,_ i. 205. _Eleocharis palustris_ (note), ii. 96. Elephants, at Teshoo Loombo, ii. 172; bogged, ii. 333; discomforts of riding, i. 400; geologising with, i. 10; path of, i. 108; purchase of, i. 381; wild, ii. 302. _Eleusine coracana,_ i. 133. _Enkianthus,_ i. 108. _Ephedra,_ ii. 84, 155. _Ephemera_ at 17,000 feet, ii. 141. _Epipactis,_ ii. 66. Equinoctial gales, ii. 144. _Equus Hemionus,_ ii. 172. _Eranoboas_ (note) i. 36, 90. _Erigeron alpinus_ (note), ii. 164. _Ervum lens,_ i. 13. _Erythrina,_ ii. 18. _Euphorbia ligulata,_ i. 46; _pentagona,_ i. 82; _neriifolia,_ i. 46, 82; _tereticaulis,_ i. 46. European plants in Himalaya, ii. 38. _Euryale ferox,_ ii. 255; seeds of, in peat, ii. 341.

F

Fair, i. 161; at Titalya, i. 118. Falconer, Dr., house of, ii. 243. _Falconeria,_ ii. 353. Falkland Islands, quartz blocks of, (note), ii. 179. Fan-Palm, ii. 279. Fear, distressing symptoms of, ii. 220. Felle, Mr., i. 55. Felspar, concretions of, i. 406. Fenny river, mouth of, ii. 343. Ferns, eatable, i. 293; European, ii. 68, 72. _Feronia elephantum,_ i. 25, 50, (note), i. 16. _Festuca ovina,_ ii. 123, (note) ii. 164. Fever, recurrence of at elevations, ii. 183. _Ficus elastica,_ i. 102; _infectoria,_ i. 26. Figs, i. 157. Fire, grasses destroyed by, i. 385; in forests, i. 146. Fire-wood, Sikkim, ii. 151. Fish, dried, ii. 309; Tibet (note), ii. 183. Fishing basket of Mechis, i. 404. Flame, perpetual, ii. 352. Flood, tradition of, i. 127; ii. 3. Florican, i. 55, 381. Forests of Sikkim, i. 165. Fossil plants of coal, i. 8; of Khasia, ii. 325; of Terai, i. 403. Frogs, Sikkim, i. 165. Fruits of Sikkim, i. 159; ii. 182. _Funaria hygrometrica,_ ii. 19. Fungi, European, ii. 73.

G

Ganges, fall of, i. 71; scenery of, i. 79. Gangetic delta, ii. 340; head of, ii. 252. Gangtok Kajee, ii. 229. Gardeners, native, i. 93. Gardens, Bhaugulpore, i. 91; Burdwan, i. 6; Calcutta Botanic, i. 3, ii. 244; Lieutenants Raban and Cave’s, ii. 284; Sir Lawrence Peel’s, i. 2. Garnets, amorphous, (note) ii. 123; sand of, i. 80, 371. Garrows, ii. 272. _Gaultheria,_ ii. 22, 182. Gelookpa, Boodhist sect. (note) i. 366. Geology of Choongtam, ii. 27; Khasia mountains, ii. 323; outer Himalaya, i. 406, Paras-nath, i. 32. _Geranium,_ ii. 19. Ghassa mountains, (note) ii. 166. Ghazeepore, i. 78. Giantchi, ii. 168, (note) ii. 131. Glaciers of Chango-khang, ii. 115; Donkia, ii. 136; Himalaya, ii. 57; Kambachen, i. 260; Kinchinjhow, ii. 134, 180; Lachen Valley, ii. 78; Yangma Valley, i. 246. Glory, ornament resembling, ii. 86; round deities’ heads, ii. 195. _Gnaphalium luteo-album,_ i. 80. Gnarem Mountain, ii. 18. Gneiss, characters of, (note) ii. 128; cleavage of, ii. 91; flexures of, i. 406. Gnow, (wild sheep), ii. 132. Goa, (antelope), ii. 157. Goats, poisoned by Rhododendrons, ii. 150; shawl-wool, ii. 88. Godowns, opium, i. 83. Goitre, i. 134. Goliath beetles, ii. 98. Goomchen, (tail-less rat), ii. 156. Goong ridge, i. 180. _Gordonia Wallichii,_ i. 102, 157. Gorh, ii. 10; Lama of, ii. 11. Goruck-nath, figure of, ii. 195, (note) i. 323. Gossamer spiders, i. 81, _Goughia,_ ii. 33. Gram, i. 13. Grand trunk-road, i. 10, 11. Granite, blocks of, ii. 310; cleavage planes of (note), i. 345; of Kinchinjhow (note), ii. 287, (note), ii. 128; phenomena of, i. 308. Grant, Dr., i. 90; Mr. J. W., report on Dorjiling, i. 116. Grapes, cultivation of, i. 92; wild in Sikkim, ii. 187. Grasses, absence of on outer Himalaya, i. 113; gigantic, i. 385. Gravel terraces and beds in Terai, i. 378, 380, 382, 401. Great Rungeet river, cross, i. 287; excursion to, i. 142. Greenstone of Khasia, ii. 287. Griffith, Dr., i. 3; (note) ii. 40, 244. _Grislea tomentosa,_ (note) i. 16. Grouse, Himalayan, ii. 113. Grove, sacred in Khasia, ii. 319. _Guatteria longifolia,_ i. 82. Gubroo, i. 345. Guitar, Tibetan, i. 304. Gum arabic, i. 60; of _Cochlospermum,_ i. 53; of _Olibanum,_ i. 29. Gunpowder, manufacture of, i. 9. Guobah of Wallanchoon, i. 217, 230. Gurjun trees, ii. 345, 348. _Gyrophora,_ ii. 130.

H

Hailstorm, i. 405. Halo, i. 69; seen from Donkia, ii. 129. _Hamamelis chinensis,_ ii. 318. Hamilton, Mr. C., i. 65. _Hardwickia binata,_ i. 50, 54. Hares, Terai, i. 399; Tibetan, ii. 157. Harrum-mo, (wild tribe), ii. 14. Hattiah island, removal of land from, ii. 353. Haze on plains, i. 374, 375. Hee hill, i. 371. _Helicteres Asoca_ (note), i. 16. _Helwingia,_ i. 126. Herbert, Major, report on Dorjiling, i. 116. _Hierochlœ,_ ii. 115. Himalaya, distant view of, i. 96; vegetation and scenery of outer, i. 108; view of from Khasia, ii. 287, 289, 297. _Hippophæ,_ ii. 43. _Hodgsonia,_ i. 395; ii. 7; _heteroclita,_ ii. 350. Hodgson, Mr., i. 122; join in Terai, i. 376; view from house, i. 123. _Holigarna,_ varnish from, ii. 330. Hollyhock, ii. 105. Honey poisoned by Rhododendron flowers, i. 201; preservation of bodies in, ii. 276; seekers, ii. 16. Hooli festival, i. 73, 389. Hopkins, Mr., on elevation of mountains, i. 326. Hornbills, i. 187. Hornets, ii. 26. Horse-chestnut, Indian, i. 394. Horse, wild, ii. 172. Hot-springs, boy passes night in, ii. 184; of Momay, ii. 133, 180; Seetakoond, i. 88; Soorujkoond, i. 27; Yeumtong, ii. 116. House, Lama’s, i. 317; Tibetan, at Yangma, i. 242; Wallanchoon, i. 211. _Houttynia,_ ii. 7. _Hydnocarpus,_ ii. 7. _Hydropeltis_ (note), ii. 318.

I

Ice, accumulation of, ii. 47; action of, i. 353 (note), ii. 121; transport of plants in, ii. 247. _Imperata cylindrica,_ i. 385. India-rubber tree, i. 102; ii. 13. Indo-Chinese races, i. 140. _Infusoria_ at 17,000 feet, ii. 123. Inglis, Mr. H., ii. 265. Insects at 4000 feet, ii. 18; Choongtam (5000 feet), ii. 26; Dorjiling (note), ii. 98; Lamteng (8000 feet), ii. 37; Momay (15,300 feet), ii. 132; Tallum (12,000 feet), ii. 68; Tunga (13,000 feet), ii. 93; Zemu river (12,000 feet) ii. 59; Zemu Samdong (9000 feet), ii. 65. Iron forges, chime of hammers, ii. 296; sand, ii. 310; smelting of, in Khasia, ii. 310; stone, i. 401. Irvine, Dr., i. 82. Islumbo pass, i. 280. Ivy, ii. 32.

J

Jaws, i. 18, 90. Japanese plants in Sikkim, i. 126; ii. 39. Jarool (_Lagerstrœmia_), ii. 327. Jasper rocks, i. 50. Jatamansi, i. 217. Jeelpigoree, i. 384; rajah of, i. 389. Jerked meat, i. 214; ii. 183. Jews’ harp, Tibetan, i. 338; ii. 219. Jhansi-jeung, _see_ Giantchi, ii. 168. Jheels, ii. 256, 309; brown waters of, ii. 263. Jigatzi (note), ii. 125, 171; temperature of, ii. 171. Job’s tears, cultivation of, ii. 289. Jongri, i. 349. Joowye, ii. 316. Jos, image of, at Yangma, i. 236. Jummul river, ii. 253. _Juncus bufonius,_ i. 80, 230. Jung Bahadoor, ii. 239, 243. Juniper, black, sketch of, ii. 55. _Juniperus recurva,_ ii. 28, 45. Junnoo mountain, i. 123, 258, 264. Jyntea hills, ii. 314.

K

_Kadsura,_ ii. 6. Kajee, i. 182. Kala-panee, ii. 285. Kambachen, or Nango pass, i. 250; top of, i. 253; village, i. 257. Kambajong, ii. 125. Kanglachem pass, i. 246. Kanglanamo pass, i. 271, 341, 350. Katior-pot (_Hodgsonia_), ii. 7. Katong-ghat, ii. 233. Kaysing Mendong (note), i. 286, 332. Keadom, ii. 101. Kenroop-bi (_Dentaria_), ii. 47. Khabili valley, i. 278. Khamba mountains, ii. 167. Khasia, climate of, ii. 282; geology of, ii. 323; leave, ii. 323; people of, ii. 273. Khawa river, i. 193. Khutrow (_Abies Smithiana_), ii. 25. Kiang, ii. 172. Kiang-lah mountains, ii. 124, 167. Kidnapping, i. 341. Kinchinjhow, ii. 41, 80, 84, 140; glacier of, ii. 134, 180. Kinchinjunga, i. 344; circuit of, i. 381; view of from Bhomtso, ii. 165; from Choongtam, ii. 14, 188; from Donkia pass, ii. 126; from Dorjiling, i. 123; from Sebolah, ii. 142; from Thlonok, ii. 50. Kishengunj, i. 98; ii. 249. Kollong rock, ii. 293. Kongra Lama, ii. 155; pass, ii. 80. Kosturah (musk-deer), i. 269. Kubra, i. 123, 272. Kulhait river, i. 281, 370; valley, i. 282. Kumpa Lepchas i. 137; Rong, i. 137. Kunker, i. 12, 29, 50, 89, 94. Kursiong, i. 109, 110, 405. Kurziuk, i. 284. Kuskus, i. 42. Kymore hills, geology of, i. 32; sandstone of, i. 39.

L

Lac, i. 9. Lacheepia, ii. 112. Lachen-Lachoong river, ii. 14, 186. Lachen Phipun, ii. 22, 43, 149; conduct of, ii. 61; tent of, ii. 78. Lachen river, ii. 30; length of, and inclination of bed, ii. 176. Lachoong Phipun, ii. 105; valley, headstreams of, ii. 120; village, ii. 103; revisited, ii. 183. _Lagerstrœmia grandiflora,_ i. 401. _Reginæ,_ ii. 327. Laghep, ii. 197. _Lagomys badius,_ ii. 156. _Lagopus Tibetanus,_ i. 93. Lailang-kot, ii. 286. Lake-beds in Yangma valley, i. 232, 234, 238, 244. Lakes caused by moraines, ii. 119. Lamas, arrival of at Tumloong, ii. 224; dance of, i. 228; music of, i. 313; ii. 218; Pemiongchi, ii. 225; of Sikkim, i. 290; of Simonbong, i. 174; worship of, i. 365; ii. 178. Lamteng, ii. 34, 96, 148. Landslips, ii. 16, 20, 97, 115. Larch Himalayan, i. 255; sketch of, ii. 55. _Larix Griffithii,_ i. 255; ii. 44. Lassoo Kajee, ii. 2. Laurels, i. 162. Lautour, Mr., ii. 345. Leaf-insect, ii. 305. Lebanon, Cedar of, i. 256. _Lecidea geographica,_ i. 221, 352; ii. 130; _oreina,_ ii. 179. Leebong, i. 143. Leeches, i. 107, 167; ii. 17; upper limit of, ii. 54. _Leguminosæ,_ absence of in Himalaya, i. 112. Lelyp, i. 205. _Lemma minor,_ i. 306. Lemon-bushes, wild, ii. 233. Lepchas, i. 127; diseases of, i. 134; dress and ornaments of, i. 130; ii. 194; food of, i. 132; music of, i. 133; peaceable character of, i. 128, 136. _Lepus hispidus,_ i. 399; _oiostolus,_ ii. 158. _Leucas,_ a weed in fields, i. 383. _Leuculia gratissima,_ i. 193, 276; _Pinceana,_ ii. 286. _Leycesteria,_ i. 206. Lhassa (note), ii. 168; notices of, i. 299; ii. 27, 172. Lichens, Arctic, i. 352; ii. 130, 165, 179. _Licuala peltata_ (note), i. 143. Lignite, i. 403. Liklo mountain, ii. 50. _Lilium giganteum_ (note), ii. 33. Little Rungeet, cross, i. 157, 175; guardhouse at, i. 371; source of, i. 181. Limboos, i. 137; language of, i. 138. Lime, deposit of, i. 407; ii. 97; nitrate of, i. 43. Limestone, at Rotas, i. 40; nummulite, ii. 266, 346; of Churra, ii. 278; spheres of, i. 55; Tibetan, ii. 177. Lime-tuff, impression of leaves on, i. 44. _Limosella aquatica,_ i. 230. _Linaria ramosissima,_ i. 42. Lingcham, i. 281, 313; Kajee of, i. 282, 284, 371. Lingo cane-bridge, ii. 12. _Linum trigynum_ (note), i. 16. Lister, Colonel, ii. 329. Lizard, i. 37; ticks on, i. 37. Lohar-ghur, i. 402. Luminous wood, ii. 151. Lushington, Mr., sent to Dorjiling, ii. 227. _Lycopodium clavatum,_ ii. 19. _Lyellia crispa,_ ii. 19. _Lymnæa Hookeri,_ ii. 156.

M

Machoo valley, ii. 109. Maddaobund, i. 18. _Magnolia, Campbellii,_ i. 125, 166; _excelsa,_ i. 125; distribution of (note), i. 166. Magras, aborigines of Sikkim, i. 139. Mahaldaram, i. 111. Mahanuddy river, i. 98, 375; ii. 250. Mahaser, a kind of carp, i. 398. Mahowa, i. 16, 63. Maidan (term as applied to Tibet), ii. 170. Mainom mountain camp on, i. 307; summit of, i. 310. Maitrya, the coming Boodh, i. 357. Maize, hermaphrodite, i. 157; roasted, ii. 78. Malayan plants in Himalaya, ii. 39. Maldah, ii. 250. Mamloo, village and waterfalls of, ii. 278. Mango, blossoming, i. 61. Mani, or praying-cylinder, i. 135, 172, 211; turned by water, i. 206. _Mantis_ of Khasia, ii. 305. _Marlea,_ ii. 33. Marmot, i. 93; head and feet of, ii. 106. Martins’ nest, spiders in, i. 46. May-fly at 17,000 feet, ii. 141. M’Lelland, Dr., i. 3. Mealum-ma (nettle), ii. 189, 336. Mechi fisherman, i. 404; river, i. 383; tribe, i. 101, 140. _Meconopsis,_ i. 81; ii. 281; _Nepalensis,_ ii. 53. Meepo, i. 198; house of, ii. 194; joined by, ii. 11; wife of, ii. 193. Megna, altered course of, ii. 341; navigation of, ii. 338. _Melastoma,_ ii. 18. Mendicant, Tibetan, ii. 189. Mendong, i. 211, 332; Kaysing (note), i. 286. _Menziesia,_ ii. 113. _Mesua ferrea,_ ii. 328. Midsummer, weather at, ii. 59. Mirzapore, i. 64. Moflong, ii. 288. Momay Samdong, arrival at, ii. 118; climate of, ii. 143; second visit to, ii. 180. Monastic establishments of Sikkim, i. 367. Monghyr, i. 87. Monkeys, i. 278; ii. 37. Mon Lepcha, i. 342. _Monotropa,_ ii. 19. Monuments of Khasia, ii. 319. Moormis, i. 139. Mooshye, ii. 314. Moosmai, ii. 268. Moraines, ancient, at Lachoong, ii. 104; at Tallum, ii. 67; at Yangma, i. 231, 246; extensive, ii. 118; indicating changes of climate, i. 380. Morung of Nepal, i. 378, 382. Mountains, deceptive appearance of, ii. 127. Moss of puff-ball, ii. 13. Mudar (_Calotropis_), i. 86. Muddunpore, i. 35. Mugs at Chittagong, ii. 345. Mulberry, wild, i. 151. Mules, Tibetan (note), ii. 228. Mungeesa Peak, i. 55. Munnipore dance, ii. 331; frontier, ii. 334; (note), ii. 329. _Murraya exotica,_ i. 44. Murwa beer, i. 133, 175, 285, 291; grain, i. 133. Mushroom, eatable, ii. 47. Musk-deer, i. 209; ii. 37. Muslin, Dacca, ii. 254. Mutton, dried saddles of, ii. 183. Myong valley (East Nepal), i. 181. Myrung, ii. 292. Mywa Guola, i. 137; sunk thermometer at, i. 198.

N

Nagas, ii. 332. Nageesa (_Mesua ferrea_), ii. 320. Namten, ii. 223. Nango mountain i. 236; or Kambachen pass, i. 250. Nanki mountain, i. 183. Napleton Major, i. 92. _Nardostachys Jatamansi,_ i. 217; (note), ii. 164. _Nauclea cordifolia,_ i. 26; _parvifolia,_ i. 26. Neongong temple, i. 311. Nepal, East, journey to, i. 178. Nepalese Himalaya, i. 125. Nepenthes, ii. 315. Nettles, i. 157; gigantic, i. 182; ii. 188. Nightingales, i. 332. Nimbus of the ancients (note), ii. 195. Ningma, Boodhist sect (note), i. 366. _Nipa fruticans,_ i. 1; ii. 355. Nishung, or Moormis, i. 139. Noacolly, ii. 339; extension of land at, ii. 341. Nonkreem, ii. 310. Nummulites of Khaaia limestone, ii. 325. Nunklow, ii. 300. Nunnery at Tumloong, ii. 191. Nursing, i. 124, 347. Nurtiung, ii. 318. Nut, Himalayan, ii. 114. Nutmegs, wild, ii. 353. _Nymphæa pygmæa,_ ii. 312.

O

Oaks, i. 109; distribution of in India (note), ii. 336; Sikkim, i. 157; upper limit of, ii. 114. Observatory at Benares, i. 74. Oil of _Bassia butyracea,_ i. 151; of _B. latifolia,_ i. 16; Kuskus, i. 42; mustard, linseed, and rape, i. 13; uggur, ii. 328; wood, ii. 348. _Olax scandens,_ i. 31. _Olibanum,_ Indian, i. 29. Olivine (note), ii. 123. Omerkuntuk, i. 32. Onglau (mushroom), ii. 47. Opium, East Indian, cultivation and manufacture of, i. 83; quality of, i. 85. _Opuntia,_ i. 205. _Orchideæ,_ growth of in Khasia, ii. 321; of Khasia, ii. 281. _Orobanche,_ Himalayan, i. 262; _Indica,_ i. 16. Ortolan, i. 98. Otters, i. 198. _Ovis Ammon,_ i. 244; ii. 132; skulls of, i. 249. _Oxalis sensitiva,_ i. 102. _Oxytropis Chiliophylla_ (note), ii. 164.

P

Pacheem, i. 111; vegetation of, i. 112. Painom river, ii. 167. Palibothra, i. 90. Palms, distribution of in Sikkim, i. 143; fan, i. 29; of Khasia, ii. 267. Palung plains, ii. 84, 152; view of from Sebolah, ii. 142. _Pandanus,_ i. 300; ii. 9. Papaw, ii. 350. Paper, manufactory at Dunkotah, i. 190; of _Astragalus,_ ii. 162; of _Daphne_ and _Edgeworthia,_ i. 205, 303; ii. 162; of Tibet, ii. 162. _Papilio Machaon,_ ii. 65; (note), ii. 68. Paras-nath, i. 12, 32; geology of, i. 32; summit of, i. 21. _Paris,_ ii. 18. _Parochetus communis,_ ii. 50. Patchouli plant, ii. 314. Patna, i. 82. Pawn, i. 99. Peaches, Sikkim, i. 158; cultivation of, ii. 185. Peacock wild, i. 30. Peat at Calcutta, ii. 341. Pea-violet, ii. 309. Peel, Sir L., garden of, i. 2. Peepsa, i. 157. Pelicans, mode of feeding, i. 80. Pemberton, Capt., treatment of his embassy in Bhotan (note), ii. 202. Pemiongchi temple, i. 327. Pemmi river (East Nepal), i. 192. Pepper, Betel, i. 99. Perry Mr., i. 98. Peuka-thlo, ii. 81. Phadong Goompa, ii. 192; confinement at, ii. 209. Phari, ii. 110. Pheasant (Kalidge), i. 255; horned, ii. 37. Phedangbos (Limboo priests), i. 138. Phenzong Goompa, ii. 192. Phieungoong, i. 332; ii. 198. Phipun, Lachen, ii. 22, 149; of Lachoong, ii. 105. _Phœnix acaulis,_ i. 145; (note), i. 143, 400; dwarf, i. 22, 382; _paludosa,_ i. 1; ii. 355; _sylvestris,_ i. 88. Phosphorescent wood, ii. 151. _Photinia,_ ii. 22. Phud (Tibet mendicant), ii. 186. _Phyllanthus emblica,_ i. 273; (note), i. 16. _Picrorhiza,_ i. 272. Pigeons, ii. 37. Pines, gigantic, ii. 108; Himalayan, i. 256; ii. 44, 198; rarity of in Sikkim, i. 169. _Pinguicula,_ ii. 40. _Pinus excelsa,_ ii. 45, 105; _Khasiana,_ ii. 282, 288, 301; _longifolia,_ i. 145, 182, 278, 280; ii. 3, 45. _Piptanthus Nepalensis,_ ii. 5. Pitcher-plant, ii. 315. _Plantago_ leaves, used to dress wounds, ii. 75. Plantain, scarlet-fruited, ii. 309; wild, i. 143. Plants, English, on Soane river, i. 45; English, on Ganges, i. 80; temperature of, i. 36; of English genera in Terai (note), i. 398. _Plectocomia,_ i. 143. Plumbago, i. 407; ii. 46. _Poa annua,_ i. 118, 221; _laxa,_ ii. 123. Poa (fibre of _Bœmeria_), i. 157. _Podocarpus neriifolia_ (note), i. 256. _Podostemon_ (note), ii. 314. Poisoners, i. 65. Poisoning of goats by rhododendrons, ii. 150; of Bhoteeas by arum-roots, ii. 75. _Polygonum cymosum,_ ii. 31. _Polypodium proliferum,_ i. 50. Pomrang, ii. 313. Pony, Tibetan, i. 118; ii. 75; (note), ii. 131. Poppy, cultivation of, i. 31; ii. 352. Porcupine, i. 205. _Potamogeton natans,_ i. 306. Potatos, culture of in East Nepal, i. 259; Khasia, ii. 277; Sikkim, i. 158. _Pothos,_ ii. 18. Praong (bamboo), i. 158, 313. _Primula petiolaris,_ i. 306; _Sikkimensis,_ ii. 77. _Prinsepia_ (note), ii. 102, 291. _Procapra picticaudata,_ ii. 157. _Prunella,_ ii. 132; _vulgaris,_ ii. 66. _Prunus,_ used for fodder, i. 359. _Pteris aquilina,_ ii. 19; (note), ii. 53. Pullop-bi (_Polygonum_), ii. 31. Pulse accelerated at great elevations, ii. 131, 142. Pundim mountain, i. 345; cliff of, i. 346. Pundua, ii. 264. Punkabaree, i. 102, 374, 403. Purnea, i. 97. _Pyrola,_ ii. 43.

Q

Quartz-beds folded, i. 406; blocks in Falkland Islands (note), ii. 179. _Quercus semecarpifolia,_ i. 187. Quoits, i. 338.

R

Raban, Lieut., ii. 333; garden of at Churra, ii. 84. Radiation, powerful in valleys, i. 209. Rageu (deer), ii. 98. Rain-fall at Churra, ii. 282; at Noacolly, ii. 340; diminution of at Rotas, i. 43; in Sikkim (Appendix), 412; Silchar, ii. 334. Rajah, Sikkim, audience of, i. 302; poverty of, i. 303; (note), ii. 216; presents from, ii. 64; punishment of, ii. 246; residence of, ii. 191, 217. Raj-ghat i. 44. Rajmahal hills, i. 95. Raklang pass, i. 292. Ramchoo lake (of Turner), ii. 143, 167. Rampore Bauleah, ii. 251. Ranee of Sikkim, presents from, ii. 227. Rangamally, i. 393. _Ranunculus aquatilis,_ ii. 156; _hyperboreus_ (note), ii. 112; _sceleratus,_ i. 45, 80. Ratong river, i. 358. Rat, tail-less, ii. 156. Red snow, absence of in Himalaya, ii. 117. Release from confinement, ii. 237. Reptiles of Khasia, ii. 305; of Sikkim, ii. 25. _Rhododendrons,_ i. 166, 167; alpine, i. 220; ii. 58; _anthopogon,_ i. 220, 349; _arboreum,_ i. 126, 200, 274, 275, 276; ii. 125; _argenteum,_ i. 116, 358; ii. 6; _Aucklandii,_ ii. 25; _barbatum,_ i. 166, 274; _campylocarpum,_ i. 261; _Dalhousiæ,_ i. 126, 162; ii. 25; distribution of at Chola (note), ii. 197; _Edgeworthii,_ ii. 25; _Falconeri,_ i. 272, 274, 307; flowering of at different elevations, ii. 181; _formosum,_ ii. 301; _Hodgsoni,_ i. 250, 274; leaves curled by cold, ii. 199; _nivale,_ ii. 89, 155; of Churra, ii. 282; poisoning of goats by, ii. 150; _setosum,_ i. 220, 349; superb at Choongtam, ii. 186. Rhubarb, gigantic, ii. 58; used as tobacco, ii. 152. Rice-paper plant (note), i. 359. Rice, Sikkim, i. 155; upper limit of cultivation, ii. 105. Ringpo, ii. 196. Ripple-mark on sandstone, i. 43, 63. Rivers, diurnal rise and fall of, ii. 69; of West Bengal, i. 33; temperature of, ii. 60; velocity of, ii. 99. Rocks, absence of scratched in Sikkim, ii. 120; falling, ii. 57; moutonnéed, ii. 136; moved by frosts, etc., ii. 179; retention of heat by, i. 222; strike of in Tibet, ii. 177. Rong (name of Lepchas), i. 127. _Rosa involucrata,_ ii. 250; _macrophylla,_ ii. 43; _sericea,_ i. 168. Rose Gangetic, (_Rosa involucrata_), ii. 255; gardens, i. 78; large-flowered, ii. 43. Rotas-ghur, i. 40; palace, i. 42. _Rottlera tinctoria,_ i. 315. Rummai, i. 394. Ryott valley, ii. 190.

S

Saddle, Tibetan, i. 296. Sakkya, invocation of, i. 229; Sing, i. 321; Thoba, i. 331. Sakkyazong, i. 186, ii. 66. Sal, i. 21. _Salix tetrasperma,_ i. 400; _Babylonica,_ ii. 32. _Salmonidæ,_ distribution of in Asia, (note) ii. 183. Salt, country in Tibet, ii. 124; monopoly of by Indian Government, ii. 339. _Salvinia,_ ii. 338. Sandal-wood, red, ii. 328. Sandstone of Kala-panee, ii. 286; of Khasia, ii. 267; of Kymore hills, i. 39; of Terai, i. 379, 402; slabs of, i. 60. Sara (crane) breeding in Tibet (note), ii. 161. Sar-nath, i. 77. Satpura range, i. 32. _Satyrium Nepalense_ (note), ii. 102. _Saussurea,_ bladder-headed, ii. 109; _gossypina,_ i. 225. _Saxifraga,_ arctic, i. 81; _ciliaris,_ ii. 280; (note) ii. 100. _Scirpus triquetra_ (note), ii. 96. _Scitamineæ,_ ii. 18. Sconce, Mr., ii. 345. Scorpions, i. 53. Scratched rocks, absence of in Sikkim, ii. 120. Seal of Bhotan Rajah, i. 372. Seasons of vegetation in Sikkim, ii. 182. Sebolah pass, ii. 141. Seetakoond bungalow and hill, ii. 352; hot springs of, i. 88; perpetual flame at, ii. 352. Sepoys, Lepcha and Tibetan, ii. 235. Shahgunj, i. 60. Shales, carbonaceous in Terai, i. 403. Sheep, breeding of, ii. 150; feeding on rhododendron leaves, i. 261; grazed at 16,000 feet, ii. 89; at 18,000 feet, ii. 170; Tibetan, i. 272; wild, i. 243, ii. 132. Sheergotty, i. 31. Shell-lac, i. 9. Shells, ii. 7; alpine, ii. 156. Shepherd’s purse, i. 221. Shigatzi (_see_ Jigatzi). Shooting, prejudice against, ii. 40. Showa (stag) antlers of, ii. 214. Shrubs, northern limits of, ii. 118. Siberian plants in Himalaya, ii, 38, 66, 63, 74. Sidingbah (note), i. 274, 276. Sikkim, climate of, i. 160; Rajah, i. 116, 298; vegetation, i. 168; Dewan, i. 298. Silchar, ii. 328. Silhet, ii. 326, 335; leave, ii. 337. Siligoree, i. 375, 399. Silok-foke, Lama of, ii. 4. Simonbong temple, i. 172. _Simulium,_ i. 157. Sinchul, ascent of, i. 124, 125; plants of, i. 125. Singdong, ii. 223. Singtam Soubah, ii. 15; at Chola, ii. 201; dismissal of, ii. 210; illness of, ii. 72; joined by, ii. 64. Singtam village, ii. 14. Sissoo, i. 395. Sitong, ii. 153. _Skimmia,_ i. 126; _laureola,_ i. 167. Sleeman, Major, reports on Thuggee, i. 67. Slopes, inclination of in Sikkim, i. 327. _Smilacina_ (a pot-herb), ii. 48. Snake-king, image of, i. 369, (note) i. 328. Snakes, ii. 25, 305. Snow, perpetual, ii. 116, 128, 169; phenomena of (note), i. 252; shades, i. 357; storms, i. 355. Snowy Himalaya, views of from Tonglo i. 184; very deceptive appearance of, i. 124. Soane, i. 35; cross, i. 38, 45, 53; elevation of bed, i. 46; mouth of, i. 82; pebbles, i. 33, 91; plants in bed of, i. 45. Soda, sesqui-carbonate of, i. 13; effloresced, ii. 157. Soil, temperature of, i. 35, 36, 45, 158, 170, 186, 219, 247; at Bhomsong, i. 305. Songboom, i. 361. Soormah river, ii. 261; basin of, ii. 256. Soorujkoond, hot-springs of, i. 27. Sound, produced by boulders in rivers, ii. 48; transmission of, i. 253. _Sparganium ramosum_ (note), ii. 96. _Sphærostema,_ ii. 33. _Sphynx atropos,_ i. 46. Spiders in martins’ nests, i. 46. _Spondias mangifera,_ i. 82. Squirrels, i. 46. Stainforth, Mr., house at Pomrang, ii. 313; at Silhet, ii. 335. _Sterculia fœtida,_ i. 39. Stick lac, i. 9. Sticks, warming (note), ii. 154. _Stipa,_ ii. 132. _Stauntonia,_ i. 112. Strawberry of the plains, i. 395; alpine, ii. 108. _Struthiopteris,_ ii. 68. _Strychnos potatorum,_ i. 50. _Stylidium,_ ii. 336. _Styloceras ratna,_ i. 399. Sulkun, i. 56. Sultangunj, rocks of, i. 90. Sundeep island, deposit of silt on, ii. 342. Sunderbunds, ii. 354; compared with Jheels, ii. 260; vegetation of, ii. 340. _Sunipia_ (note), ii. 10. Sunnook, i. 317. Sunrise, false, i. 63. Sunset, false, i. 63; in Tibet, ii. 173. Suspension bridge, iron, i. 199. Syenite, blocks of, ii. 302. _Symplocos,_ dye from, ii. 41. Syong, ii. 291.

T

Taktoong river, ii. 32. _Talauma Hodgsoni,_ i. 162. Taldangah, i. 12. Tallum Samdong, ii. 67, 96. Tamarind tree, i. 17. Tamarisk, i. 392. Tambur river, i. 194; elevation and slope of bed, i. 200. Tanks, plants in, i. 62; movements of water in, ii. 342. Taptiatok (E. Nepal), i. 204. Tassichooding temples, i. 257. Tassiding, i. 289, 315; temples, i. 319; foundation, i. 325. Tchebu Lama, i. 302; ii. 5, 193; house and chapel of, ii. 194. Tchiru (antelope), ii. 157. Tchuka (rhubarb), ii. 58. Tea, buttered, ii. 78; brick, i. 297; made of _Photinia,_ etc., ii. 22; Tibetan, ii. 78. Teal, English, ii. 158. Tea-plants, i. 5; cultivation of in Sikkim, i. 144; cut by hail at Dorjiling, i. 408; at Myrung, ii. 92; Chittagong, ii. 347. Teelas, ii. 262, 327. Teesta river, at Bhomsong, i. 297; exit from mountains, i. 396; in plains, i. 392; junction with Great Rungeet, i. 154; signification of, i. 398; temperature of, i. 397; ii. 60. Teeta (febrifuge), i. 272. Temples of Catsuperri, i. 365; Changachelling, i. 368; Choongtam, ii. 21; Doobdi, i. 366; Neongong, i. 311; Pemiongchi, i. 327; Phadong, ii. 192; Simonbong, i. 172; Tassichooding, i. 257; Tassiding, i. 319; Wallanchoon, i. 228; Yangma, i. 235; various, i. 313; mode of building, i. 311; worship in, i. 312, 365; ii. 178. Tendong, i. 127; ii. 3; summit of, ii. 6. Terai, i. 100, 104; definition of, i. 377; excursion to, i. 373; meteorology of, i. 384; of Khasia, ii. 266; seizure of, ii. 240; vegetation of, i. 101. Terraces, at Baisarbatti, i. 401; junction of Zemu and Thlonok, ii. 53; Momay, ii. 119; Yalloong, i. 270; Yangma, i. 234, 242. Terya, ii. 226. Teshoo Loombo (note), ii. 171. _Tetrao-perdrix nivicola,_ ii. 113. _Thalictrum,_ i. 19; _alpinum,_ ii. 115; _glyphocarpum_ (note), i. 24. Thermometer, black bulb, i. 15; boiling-point, ii. 113, 153, Appendix, 453; lost, ii. 184; minimum left on Donkia pass, ii. 129; sunk, i. 198; Appendix, 441, 451. Thigh-bone, trumpet of, i. 173, 314. _Thlaspi arvense,_ ii. 68. Thlonok river, ii. 47. Thomson, Dr., joined by, ii. 238. Thugs, river, i. 67; suppression of, i. 65. Tibet, animals of, ii. 93, 157, 173; enter, ii. 155; inhospitality of climate, i. 299; snow-line, elevation of in, ii. 128, 175. Tibetans, i. 262; blackening faces of women, ii. 172; camp of, ii. 85; charm-box, i. 270; child’s coral, ii. 87; churns, ii. 77; cups, i. 212; diet, i. 212; Dingpun, ii. 160; dogs, i. 204; drunk, i. 230; guitar, i. 304; headdresses, ii. 86; hospitality, ii. 94; household, i. 212; houses, ii. 67; pipe, i. 212; salute, i. 203; sepoys, ii. 160, 200, 235; tea, i. 212; ii. 78; tents, ii. 77. Ticks, i. 166, 279; ii. 79. Tidal-wave, ii. 343. Tide in Bay of Bengal, ii. 340; in Sunderbunds, ii. 354. Tiger hunt, i. 56. Tikbotang, ii. 228. Tingri, ii. 169. Titalya, i. 100, 376. Toad, Javanese, ii. 96. Tobacco, Chinese, ii. 232; made from rhubarb, ii. 152. Toddy-palm, i. 34, 39, 88. Tofe Choney, i. 16. Tomo-chamo mountain, ii. 122. Tong (arum-roots prepared for food), ii. 49; collection and preparation of, ii. 65. Tonglo, i. 158; camp on, i. 183; elevation of, i. 171; excursion to, i. 155; summit of, i. 167; temperature of, i. 170; vegetation of, i. 167. Took (_Hydnocarpus_), ii. 7. (_See_ Chaulmoogra). Toon (_Cedrela_), i. 193, 312. Tourmalines, i. 224; ii. 27. Toys, children’s in Sikkim, i. 338. Travelling equipment, i. 179. Tree-fern, i. 110; ii. 13; in Silhek, ii. 336. Trees, burnt, i. 151; limits of in Sikkim, ii. 75. _Trichomanes_, i. 358. Tripe de roche, ii. 130. Tsang, province of Tibet, ii. 168. Tukcham mountain, ii. 33. Tuk-vor, i. 371. Tumloong, ii. ; confinement at, ii. 213; dismissal from, ii. 228; meteorology of, ii. 218. Tungu, ii. 73, 148, 149; meteorology of, ii. 95. Tunkola, i. 123. Tunkra mountain, ii. 102; pass, ii. 109; plants of, ii. 112. Tuquoroma, i. 222. Turner, Captain, route to Jigatzi (note), ii. 125. Turnips, alpine cultivation of, ii. 88.

U

Uggur oil (_Aquilaria_), ii. 328. Unicorn of MM. Huc and Gabet, ii. 158. _Urceola elastica_ ii. 351. _Urtica crenulata_, ii. 188, 336; _heterophylla_, i. 182. _Urticeæ_, i. 157. _Usnea_, ii. 10.

V

_Vacciniæ_, rarity of in upper Himalaya (note), ii. 145. _Vaccinium_, ii. 22; _serpens_, i. 162. Vakeel sent to Dorjiling, ii. 2. _Valeriana Jatamansi_, i. 217. _Vanda cœrulea_, ii. 319, 321; _Roxburghia_, i. 28. Varnish, black of Munnipore, ii. 330. _Valeria robusta_, i. 21. Vegetation, of Chittagong, ii. 346; of Himalaya, ii. 38; of Jheels, ii. 257; of Khasia, ii 281; of Terai, i. 101; progress of at different elevations, ii. 145, 181; tropical at the base of Kinchinjunga, i. 341; zones of at Dorjiling, i. 142; zones of in Sikkim, i. 348. _Veronica Anagallis_, i. 80. _Vespa magnifica_, ii. 29. _Villarsia cristata_, i. 62; Indica, i. 62. Vindhya hills, i. 32. _Vitex Agnus-castus_, i. 374. _Vitis Indica_, ii. 187.

W

Wallanchoon, i. 227; climate of, i. 218; houses at, i. 211; pass, i. 224; plants on pass, i. 225; village, i. 209. _Wallichia_ palm, ii. 18. Wallich, Dr., i. 4. Walloong, i. 209, 215. Walnuts, Sikkim, i. 334, 338. Ward, Lieut, i. 65. Water-plants, i. 62. Well, old, i. 41. _Wightia_, grasping roots of, i. 165. Willow, ii. 32; of Terai, i. 400; weeping, i. 365. Winds, hot, i. 15; of Tibet, ii. 159, 163; of Sikkim, Appendix, 403. Woodcock of Chittagong, ii. 350: at Barfonchen, ii. 199; at Neongong, i. 306. Wood-oil (_Dipterocarpus_), ii. 348. _Woodsia_, ii. 130. Worm of Sikkim, ii. 26.

Y

Yak, i. 212: breeding, ii. 150; flock of, ii. 150; wild, i. 214. Yalloong ridge, i. 273; valley, i. 267. Yamroop, i. 277. Yangma, cultivation at, i. 238; geology of, i. 248; Guola, i. 229; houses at, i. 241; temperature at, i. 247; temples, i. 235; village, i. 238. Yangyading, i. 277. Yankoong village, ii. 228. Yankutang, i. 275. Yaru-tsampu river, i. 299; ii. 124; (note), ii. 171. Yelpote (_Bassia_), i. 151. Yeumtong, ii. 115; second visit to, 181. Yeumtso, ii, 159; elevation of, ii. 174; lake, ii. 163; temperature of soil at, ii. 174. Yew, i. 168, 191, 274, 280; ii. 45; distribution of, ii. 2525; in Khasia, ii. 282. Yoksun, i. 335; lake, i. 360.

Z

Zemindars of Bengal, i. 388. Zemu river, camp on, ii. 56; Samdong, ii. 43, 148. _Zannichellia_, i. 45; _palustris_, ii. 156. Zobo, ii. 213. Zodiacal light, i. 63.