Part 5

Dr. Buckland relates that in certain places liable to earthquakes, their extent has been measured by _bowls of treacle_, the inclination of the treacle in the bowl showing the quantum of shock; and elsewhere (by a watchmaker) in Scotland, by placing a clock against each of the four walls of an apartment, and marking the centre of the disk of the pendulum with chalk: when the shock took place, the derangement caused the pendulum to strike against the back and front of the clock-case, when, of course, a mark would be left indicative of the phenomenon, though not of its amount.

THE DRUMMOND LIGHT.

The importance of simplicity in inventions for popular use, has been shown in the late Lieutenant Drummond's apparatus for illuminating lighthouses with his oxyhydrogen light; that is, a stream of oxygen and another of hydrogen, directed upon a ball of lime. Experimentally, the light has succeeded beyond the expectation of the inventor; but the machinery or apparatus remains to be simplified before it can be worked by the keepers of lighthouses.

ST. PIERRE'S "PAUL AND VIRGINIA."

Baron Humboldt, in his _Cosmos_, vol. ii., pays the following eloquent tribute to that small production of the creative imagination to which Bernardin de St. Pierre owes the fairest portion of his literary fame--Paul and Virginia--a work such as scarcely any other literature can show.

"It is," says Humboldt, "a simple, but living picture of an island in the midst of the tropic seas, in which, sometimes smiled on by serene and favouring skies, sometimes threatened by the violent conflict of the elements, two young and graceful forms stand out picturesquely from the wild luxuriance of the vegetation of the forest, as from a flowery tapestry. Here the aspect of the sea, the grouping of the clouds, the rustling of the breeze in the bushes of the bamboo, and the waving of the lofty palmo, are painted with inimitable truth.

"Bernardin de St. Pierre's master-work, Paul and Virginia, accompanied me into the zone to which it owes its origin. It was there read for many years by my dear companion and friend, Bonpland, and myself; and there (let this appeal to personal feelings be forgiven) under the silent brightness of the tropical sky, or when, in the rainy season, on the shores of the Orinoco, the thunder crashed, and the flashing lightnings illuminated the forest, we were deeply impressed and penetrated with the wonderful truth with which this little work paints the power of nature in the tropical zone in all its peculiarity of character.

"A similar firm grasp of special features, without impairing the general impression, or depriving the external materials of the free and animating breath of poetic imagination, characterises in an even higher degree the ingenious and tender author of "Atala," "René," "the Martyr," and the "Journey to Greece and Palestine." The contrasted landscapes of the most varied portions of the earth's surface are brought together, and made to pass before the mind's eye with wonderful distinctness of vision: the serious grandeur of historic remembrances could alone have given so much depth and repose to the impressions of a rapid journey."

MYTHOLOGY OF SCIENCE.

M. Arago, in his brilliant _eloge_ on Fourier, observes:--"The ancients had a taste, or rather a passion, for the marvellous, which made them forget the sacred ties of gratitude. Look at them, for instance, collecting into one single group the high deeds of a great number of heroes, whose names they have not even deigned to preserve, and attributing them all to Hercules. The lapse of centuries has not made us wiser. The public in our time also delight in mingling fiction with history. In all careers, particularly in that of the sciences, there is a design to create Herculeses. According to the vulgar opinion, every astronomical discovery is attributable to Herschel. The theory of the motions of the planets is identified with the name of Laplace, and scarcely any credit is allowed to the important labours of D'Alembert, Clairaut, Euler, and Lagrange. Watt is the sole inventor of the steam-engine, whilst Chaptal has enriched the chemical arts with all those ingenious and productive processes which secure their prosperity." To countervail this error, Arago continues: "Let us hold up to legitimate admiration those chosen men whom nature has endowed with the valuable faculty of grouping together isolated facts, and deducing beautiful theories from them; but do not let us forget that the sickle of the reaper must cut down the stalks of corn, before any one can think of collecting them into sheaves."

EL DORADO OF SIR WALTER RALEIGH.

The term _El Dorado_ is commonly considered to have reference to the sovereignty teeming with precious metals, which had long been sought for in vain by Spanish adventurers. Their expeditions in quest of it were directed to the interior of the vast region lying between the Orinoco and the Amazon, or Guiana. The rocks were represented as impregnated with gold, the veins of which lay so near the surface as to make it shine with a dazzling resplendency. The capital, Manoa, was said to consist of houses covered with plates of gold, and to be built upon a vast lake, named Parima, the sands of which were auriferous.

We abridge the following new version of this "romance of history," from a brilliant paper on the life and works of Raleigh, in the _Edinburgh Review_.

The term _El Dorado_ was not originally used to designate any particular place; it signified generally 'the gilded,' or 'golden,' and was variously applied. According to some, it was first used to denote a religious ceremony of the natives, in covering the anointed body with gold-dust. The whole of Guiana was, on account of the above usages, sometimes designated _El Dorado_; but the locality of the fable varied.

The question, however, to be solved is, whence arose the belief that a district so marvellously abundant with the precious metals existed in the interior of Guiana; and the solution appears to have been left to Humboldt. While exploring the countries upon the Upper Orinoco, he was informed that the portion of Eastern Guiana, lying between the rivers Essequibo and Branca is 'the classical soil of the Dorado of Parima.' In the islets and rocks of mica, slate, and talc, which rise up within and around a lake adjoining the Parima river, reflecting from their shining surfaces the rays of an ardent sun, we have materials out of which to form that gorgeous capital, the temples and houses of which were overlaid with plates of beaten gold.

With such elements to work upon, heated fancies, aided by the imperfect vision of distant and dubious objects, might easily create that fabulous superstructure. We may judge of the brilliancy of these deceptive appearances, from learning that the natives ascribed the lustre of the Magellanic clouds, or nebula of the southern hemisphere, to the bright reflections produced by them. There could not well be a more poetical exaggeration of the lustrous effects produced by the metallic hues of rocks of talc. These details, in which M. de Pons, a somewhat later traveller, who long resided in an official capacity in the neighbouring countries, fully concurs, in all probability point to the true origin of this remarkable fable. The well-known failure of Raleigh did not discourage other adventurers, who were found in quick succession; the last always flattering themselves with the hope that the discovery of _El Dorado_ would ultimately be realized.

AMBER, A SOURCE OF INTERNATIONAL TRADE.

The amber trade, which was probably first directed to the west Cimbrian coasts, and only subsequently to the Baltic and the country of the Esthonians, owes its first origin to the boldness and perseverance of Phoenician coast navigators. In its subsequent extension, it offers a remarkable instance of the influence which may be exerted by a predilection for even a single foreign production, in opening an inland trade between nations, and in making known large tracts of country. In the same way that the Phocæan Massilians brought the British tin across France to the Rhone, the amber was conveyed from people to people through Germany, and by the Celts on either declivity of the Alps to the Padus, and through Pannonia to the Borysthenes. It was this inland traffic which first brought the coasts of the Northern ocean into connexion with the Euxine and the Adriatic.--_Humboldt's Cosmos._

ANTIQUITY OF LIGHTNING CONDUCTORS.

A story was formerly repeated in Germany, after Father Angelo Cortenoria, that the tomb of the hero of Clusium, Lars Porsena, described by Varro, ornamented with a bronze head and bronze pendent chains, was an apparatus for atmospheric electricity, or for conducting lightning, (as were, according to Michaelis, the metal points on Solomon's temple); but the tale obtained currency at a time when men were much inclined to attribute to ancient nations the remains of a supernaturally revealed primitive knowledge, which was soon after obscured.

The most important notice of the relation between lightning and conducting metals (a fact not difficult of discovery) still appears to be that of Ctesias: he possessed two iron swords, presents from the King Artaxerxes Mnemon, and from his mother Parysatis, which, when planted in the earth, averted clouds, hail, and strokes of lightning. He had himself seen the operation, for the king had twice made the experiment before his eyes. The exact attention paid by the Etruscans to the meteorological processes of the atmosphere in all that deviated from the ordinary course of phenomena, makes it to be lamented that nothing has come down to us from their Fulgur red books. The epochs of the appearance of great comets, of the fall of meteoric stones, and of showers of falling stars, would no doubt have been found recorded in them, as in the more ancient Chinese annals, of which Edward Biot has made use. Creuzer has attempted to show, that the natural features of Etruria may have influenced the peculiar turn of mind of its inhabitants. A "calling forth" of the lightning, which is ascribed to Prometheus, reminds us of the pretended "drawing down" of lightning by the Fulguratores. This operation consisted in a mere conjuration, and may well have been of no more efficacy than the skinned ass' head, which, in the Etruscan rites, was considered a preservative from danger in their thunder-storms.--(_See Notes to Humboldt's Cosmos_, vol. ii.)

HOW THE DEAF MAY HEAR.

About 1738, a merchant of Cleves, named Jorissen, who had become almost totally deaf, sitting one day near a harpsichord, while some one was playing--and having a tobacco-pipe in his mouth, the bowl of which rested accidentally against the body of the instrument--was surprised to hear all the notes most distinctly. By a little reflection and practice, he again attained the use of this valuable sense; for he soon learned--by means of a piece of hard wood, one end of which he placed against his teeth, while another person placed the other end on _his_ teeth--to keep up a conversation, and to be able to understand the least whisper. The effect thus described is the same, if the person who speaks rests his stick against his throat or his breast; or when one rests the stick which he holds in his teeth against some vessel into which the other speaks.

DRYING WOOD FOR VIOLINS.

Some amusing instances are related of the efficiency of "the Application of Heated Currents to Manufacturing and other Purposes," once patented by Davison and Symington. Thus, a violin had been in the owner's possession for upwards of sixteen years, how old it was when he first had it is not known. Upon being exposed to this process, it lost in eight hours no less than five-sixths (nearly five and two-thirds) per cent. of its weight. This there is every reason to believe was owing to the blocks glued inside, for the purpose of holding the more slender parts together. Instrument makers would do well to see that all parts, however mean their position in the instrument, are properly seasoned, or divested of moisture; for surely water cannot improve sound.

A violin-maker of high reputation, having an order to make an instrument for one of the first violinists of the day, was requested to have the wood seasoned by the new process; only three days were allowed for the experiment, in which the wood was seasoned and sent home. The two heaviest pieces were reduced in weight 2-1/2lbs., which is equal to two pints of water.

It is ascertained that, by this means of drying, the effect of age has been given to the instrument made from the above wood; and it became _first fiddle_ in the orchestra of Her Majesty's Theatre. The wood had been in the possession of its owners for eight years; and it was sent from Switzerland, in the first instance, as dry wood.[6]

Footnote 6:

In proof of the economy of Messrs. Davison and Symington's invention applied to the manufacture and cleansing of brewers' casks, it is stated that through its adoption at Truman's brewery, Spitalfields, a saving of 300 tons of coals was effected annually.

COLUMBUS'S OWN SHIP JOURNAL.

Columbus has left us some charming descriptions of his own discoveries; though it is only recently that we have obtained the knowledge of his own ship's journal, of his letters to the treasurer Sanchez, to Donna Juana de la Torre, governess of the infant Don Juan, and to Queen Isabella. Humboldt has sought to show with how deep a feeling and perception of the forms and the beauty of nature the great discoverer was endowed, and how he described the face of the earth, and the "new heaven" which opened to his view, with a beauty and simplicity of expression which can only be fully appreciated by those who are familiar with the ancient force of the language as it existed at the period.

The aspect and the physiognomy of the vegetation, the impenetrable thickets of the forest, "in which one can hardly distinguish which are the flowers and leaves belonging to each stem;" the wild luxuriance which clothed the humid shores; the rose-coloured flamingoes fishing at the mouth of the rivers in the early morning, and giving animation to the landscape, attract the attention of the old navigator while sailing along the coast of Cuba, between the small Lucayan islands and the Jardinillos. Each newly-discovered land appears to him still more beautiful than those he had before described; he complains that he cannot find words in which to record the sweet impressions which he has received.

"The loveliness of this new land," says the discoverer, "far surpasses that of the Campina de Cordoba. The trees are all bright with ever-verdant foliage, and perpetually laden with fruits. The plants on the ground are tall and full of blossoms. The breezes are mild like those in April in Castille; the nightingales sing more sweetly than I can describe. At night, other small birds sing sweetly, and I also hear our grasshoppers and frogs. Once I came into a deeply-enclosed harbour, and saw high mountains which no human eye had seen before, from which lovely waters streamed down. The mountain was covered with firs, pines, and other trees of very various form, and adorned with beautiful flowers. Ascending the river, which poured itself into the bay, I was astonished at the cool shade, the crystal clear water, and the number of singing birds. It seemed as if I could never quit a spot so delightful--as if a thousand tongues would fail to describe it, as if the spell-bound hand would refuse to write."

We have here, from the journal of an unlettered seaman, the power which the beauty of nature, manifested in her individual forms, may exert on a susceptible mind. Feelings ennoble language; for the prose of the admiral, especially when, on his fourth voyage, at the age of 67, he relates his wonderful dream on the coast of Veragua, is, if not more eloquent, yet far more moving, than the allegorical pastoral romance of Boccacio and the two Arcadias of Sannazaro and Sydney; than Garcilasso's Salicio y Nemoroso; or than the Diana of Jorge de Montemayor.

EARLY INCITEMENTS TO A SCIENTIFIC STUDY OF NATURE.

Baron Humboldt, in the opening of his _Cosmos_, vol. ii., recalls the lessons of experience, which tell us how often impressions received by the senses from circumstances, seemingly accidental, have so acted on the youthful mind as to determine the whole direction of the man's course through life. Childish pleasure, in the form of countries and of seas, as delineated in maps; the desire to behold those southern constellations which have never risen in our horizon; the sight of palms and of the cedars of Lebanon, figured in a pictorial Bible, may have implanted in the spirit the first impulse to travel in distant lands.

"If I might (says Humboldt) have recourse to my own experience, and say what awakened in me the first beginnings of an inextinguishable longing to visit the tropics, I should name George Forster's descriptions of the islands of the Pacific--paintings, by Hodge, in the house of Warren Hastings, in London, representing the banks of the Ganges--and a colossal dragon-tree in an old tower of the Botanic Gardens at Berlin."

THE RIGHTS OF WHITEBAIT.

Formerly, whitebait were considered to be the young of the shad; and only of late years has the misnamed fish taken its proper position. It appears that Mr. Yarrell, the able naturalist, was one morning in March struck with the early appearance of whitebait in a fishmonger's shop in St. James's; and knowing that shads, which they were supposed to be, did not make their appearance till much later (May), he took up the matter, and persevered in a course of investigation, which lasted from March to August, 1828. The specific distinction between the two fishes, on which Mr. Yarrell relies as of the greatest value, is the difference of their anatomical character; and especially in the number of vertebræ, or small bones, extending from the back-bone. "The number of vertebræ in the shad," he states, "of whatever size the specimen may be, is invariably fifty-five, while the number in the whitebait is uniformly fifty-six; even in a fish of two inches, with the assistance of a lens, their exact number may be distinctly made out."

CATCHING ELECTRIC EELS.

Humboldt gives a very interesting narrative of the mode of the capture of the gymnoti employed by the Indians of South America. This is done by rousing the eels by driving horses and mules into the ponds which those fish inhabit, and harpooning them when they have exhausted their electricity upon the unhappy quadrupeds.

"I wished," says Humboldt, "that a clever artist could have depicted the most animated period of the attack; the groups of Indians surrounding the pond, the horses, with their manes erect, and eye-balls wild with pain and fright, striving to escape from the electric storm which they had roused, and driven back by the shouts and long whips of the excited Indians, the livid yellow eels, like great water-snakes, swimming near the surface, and pursuing their enemy: all these objects presented a most picturesque and exciting _ensemble_. In less than five minutes, two horses were killed: the eel, being more than five feet in length, glides beneath the body of the horse, and discharges the whole strength of its electric organ; it attacks at the same time the heart, the digestive viscera, and above all, the gastric plexus of nerves. I thought the scene would have had a tragic termination, and expected to see most of the quadrupeds killed; but the Indians assured me that the fishing would soon be finished, and that only the first attack of the gymnoti was really formidable. In fact, after the conflict had lasted a quarter of an hour, the mules and horses appeared less alarmed; they no longer erected their manes, and their eyes expressed less pain and terror. One no longer saw them struck down in the water; the eels, instead of swimming to the attack, retreated from their assailants, and approached the shore."

The Indians now began to use their missiles; and by means of the long cord attached to the harpoon, jerked the fish out of the water without receiving any shock so long as the cord was dry. All the circumstances narrated by Humboldt establish the close analogy between the gymnotus and torpedo in the vital phenomenon attending the exercise of their extraordinary means of offence. The exercise is voluntary and exhaustive of the nervous energy; and, like voluntary muscular effort, it needs repose and nourishment to produce a fresh accumulation.

SIR WILLIAM HERSCHEL'S FIRST TELESCOPE.

Sir William Herschel arrived in England from Hanover, his birth-place, about the end of the year 1759, when he was in his 21st year. He was bred a professor of music, and went to live at Halifax, where he acquired, by his own application, a considerable knowledge of mathematics; and, having studied astronomy and optics in the popular writings of Ferguson, he was anxious to witness with his own eyes the wonders of the planetary system. He accordingly borrowed of a friend a telescope, two feet in focal length; and, having directed it to the heavens, he was so delighted with the actual sight of phenomena, which he had previously known only from books, that he commissioned a friend to purchase for him in London a telescope, with a high magnifying power. Fortunately for science, the price of such an instrument greatly exceeded his means, and he immediately resolved to construct a telescope with his own hands. After encountering the difficulties which every amateur at first experiences, in the casting, grinding, and polishing, of metallic specula for reflecting telescopes, he completed, in 1776, a reflecting instrument, _five feet_ in focal length, with which he was able to observe the ring of Saturn, and the satellites and belts of Jupiter. This telescope was completed when he resided at Bath, where he acquired by degrees, and in his leisure hours, that practical knowledge of optics and mechanics which was necessary for such a task.

His experience in this scientific art was of the most remarkable kind; and, by 1781, he had constructed so many telescopes, as to be better furnished with the means of surveying the heavens than were possessed by any other astronomer, in either of the fixed observatories in Europe.

WONDERS OF AUSTRALIA.