Part 17
There are high countries on the earth, which seem to be points of division marked by nature for the distribution of the waters. In Europe, the environs of Mount St. Goddard are one of these points; another is situate between the provinces of Belozera and Wologda, in Muscovy, from whence many rivers descend, some of which go to the White Sea, others to the Black, and some to the Caspian. In Asia there are several, in the country of Mogul Tartary, from whence rivers flow into Nova Zembla, others to the Gulph Linchidolin, others to the sea of Corea, others to that of China: and so likewise the Little Thibet, whose waters flow towards the sea of China; the Gulph of Bengal, the Gulph of Cambay, and the Lake Aral; in America, the province of Quito; whose rivers run into the North and South Seas, and the Gulph of Mexico.
In the old continent there are about 430 rivers, which fall directly into the ocean, or into the Mediterranean and Black Seas; but in the new continent not more than 145 rivers are known, which fall directly into the sea: in this number I have comprehended only the great rivers, like the Somme in Picardy.
All these rivers carry to the sea a great quantity of mineral and saline particles, which they have washed from the different soils through which they have passed. The particles of salt, which are easily dissolved, are conveyed to the sea by the water. Some philosophers, and among the rest Halley, have pretended that the saltness of the sea proceeded only from the salts of the earth, which the rivers transport therein. Others assert, that the saltness of the sea is as ancient as the sea itself, and that this salt was created that the waters might not corrupt; but we may justly suppose that the sea is preserved from corruption by the agitations produced by the winds and tides, as much as by the salt it contains; for when put in a barrel it corrupts in a few days; and Boyle relates, that a mariner, who was becalmed for 13 days, found, at the end of that time, the water so infected, that if the calm had not ceased, the greatest part of his people would have perished. The water of the sea is also mixed with a bituminous oil, which gives it a disagreeable taste, and renders it very unhealthful. The quantity of salt contained in sea water is about a fortieth part, and is nearly equally saline throughout, at top as well as bottom, under the line, and at the Cape of Good Hope; although there are several places, as off the Mosambique Coast, where it is salter than elsewhere.[317:A] It is also asserted not to be so saline under the Arctic Circle, which may proceed from the amazing quantities of snow, and the great rivers which fall into those seas, and because the heat of the sun produces but little evaporation in hot climates.
Be this as it may, I conceive that the saltness of the sea is not only caused by the banks of salt at the bottom of the sea, and along the coasts, but also by the salts of the earth, which the rivers continually convey therein; and that Halley had some reason to presume that in the beginning of the world the sea had but little or no saltness; that it is become so by degrees, and in proportion as the rivers have brought salts therein; that this saltness is every day increasing, and that consequently, by computing the whole quantity of salt brought by all the rivers, we might attain the knowledge of the age of the world by the degrees of the saltness of the sea.
Divers and pearl fishers assert, according to Boyle, that the deeper they descend into the sea, the colder is the water; and that the cold is so intense at considerable depths, that they cannot remain there so long under water, but are obliged to come up again much sooner than when they descended to only a moderate one. It appeared to me that the weight of the water might be as much the cause of compelling them to shorten their usual time as the intenseness of the cold, when they descend to a depth of 3 or 400 fathoms; but, in fact, divers scarcely ever descend above an hundred feet. The same author relates, that in a voyage to the East-Indies, beyond the line, at about 35 degrees south latitude, a sounding lead of 30 or 35lb weight was sunk to the depth of 400 fathoms, and that being pulled up again, it had become as cold as ice. It is also a frequent practice with mariners to cool their wine at sea by sinking their bottles to the depth of several fathoms, and they affirm the deeper the bottles are sunk, the cooler is the wine.
These circumstances might induce us to presume that the sea is salter at the bottom than at the surface; but we have testimonies which prove the contrary, founded on experiments made to fill vessels with sea water, which were not opened till they were sunk to a certain depth, and the water was found to be no salter than at the surface. There are even some places where the water at the surface is salt, and that at the bottom fresh; and this must always be the case where there are springs at the bottom of the sea, as near Goo, Ormus, and even in the sea of Naples, where there are hot springs at the bottom.
There are other places where sulphurous springs and beds of bitumen have been discovered at the bottom of the sea, and on land there are many of these springs of bitumen which run into it.
At Barbadoes there is a pure bitumen spring, which flows from the rocks into the sea: salt and bitumen, therefore, are predominant matters in the sea water: but it is also mixed with many other matters; for the taste of water is not the same in every part of the sea; besides, the agitation and the heat of the sun alters the natural taste which the sea should have; and the different colour of different seas, at different times, prove that the waters of the sea contain several kinds of matters, either which it loosens from its own bottom, or are brought thither by rivers.
Almost all countries watered by great rivers are subject to periodical inundations, those which are low, and derive their sources from a great distance, overflow the most regularly. Every person almost has heard of the inundations of the Nile, which preserves the sweetness and whiteness of its waters, though extended over a vast tract of country, and into the sea. Strabo and other ancient authors have written that it had seven mouths, but there now remain only two which are navigable; there is a third canal which descends to Alexandria, and fills the cisterns there, and a fourth which is still smaller; but as they have for a long time neglected to clean their canals, they are nearly choaked up. The ancients employed a great number of workmen and soldiers, and every year, after the inundation, they carried away the mud and sand which was in these canals. The cause of the overflowing of the Nile proceeds from the rains which fall in Ethiopia. They begin in April and do not cease till September; during the first three months, the days are serene and fair, but as soon as the sun goes down the rains begin, nor stop till it rises again, and are generally accompanied with thunder and lightning. The inundation begins in Egypt about the 17th of June; it generally increases during 40 days, and diminishes in about the same time; all the flat country of Egypt is overflowed; but this inundation is much less now than it was formerly, for Herodotus tells us, that the Nile was 100 days in swelling, and as many in abating: if this is true, we can only attribute the cause thereof to the elevation of the land, which the mud of the waters has heightened by degrees, and to the diminution of the mountains in Africa, from whence it derives its source. It is very natural to believe that these mountains have diminished, because the abundant rains which fall in these climates during half the year sweep away great quantities of sand and earth from the mountains into the valleys, from whence the torrents wash them into the Nile, which carries great part into Egypt, where it deposits them in its overflowings.
The Nile is not the only river whose inundations are regular; the river Pegu is called the _Indian Nile_, because it overflows regularly every year; it inundates the country for more than 30 leagues from its banks; and, like the Nile, leaves an abundance of mud, which so greatly fertilizes the earth, that the pasturage is excellent for cattle, and rice grows in such great abundance, that every year a number of vessels are laden with it, without leaving a scarcity in the country.[321:A] The Niger, or what amounts to the same, the upper part of the Senegal, likewise overflows and covers all the flat country of Nigritia; it begins nearly at the same time as the Nile, and increases also for 40 days: the river de la Plata, in Brasil, also overflows every year, and at the same time as the Nile. The Ganges, the Indus, the Euphrates, and some others, overflow annually; but all rivers have not periodical overflowings, and when inundations happen it is the effect of many causes, which combine to supply a greater quantity of water than common, and, at the same time, to retard its velocity. We have before observed, that in almost all rivers the inclination of their beds diminishes towards their mouths in an almost insensible manner; but there are some whose declivity is very sudden in some places, and forms what is termed a _cataract_, which is nothing more than a fall of water, quicker than the common current of the river. The Rhine, for example, has two cataracts, the one at Bilefield, and the other near Schafhouse: the Nile has many, and among the rest two which are very violent, and fall from a great height between two mountains; the river Wologda, in Muscovy, has also two near Ladoga; the Zaire, a river of Congo, begins by a very large cataract, which falls from the top of a mountain; but the most famous is that of Niagara, in Canada, that falls from a perpendicular height of 156 feet, like a prodigious torrent, and is more than a quarter of a mile broad: the fog, or mist, which the water makes in falling, is perceived at five miles distance, and rises as high as the clouds, forming a very beautiful rainbow when the sun shines thereon. Below this cataract there are such terrible whirlpools, that nothing can be navigated thereon for six miles distance, and above the cataract the river is much narrower than it is in the upper lands[323:A]. The description given of it by _Father Charlevoix_ is as follows:
"My first care, when I arrived, was to visit the most beautiful cascade that is, perhaps, in nature; but I immediately discovered that Baron la Hontain was deceived so greatly, both in its height and figure, that one might reasonably imagine he had never seen it.
"It is true, that if we measure its height by the three mountains you are obliged to ascend in going to it, there is not much abatement to be made of the 600 feet, which the map of M. Delisse gives it, who doubtless advanced this paradox only on the credit of the Baron la Hontain, and Father Honnepin; but after I arrived at the top of the third mountain, I observed that in the space of three leagues, which I afterwards had to go to this fall of water, although you are forced sometimes to ascend, you must nevertheless descend still more, and this is what travellers do not appear to have paid proper attention to. As we can only approach the cascade on one side, nor see it but in the profile, it is not easy to measure its height by instruments: experiments have been made to do it by a long cord, tied to a pole, and after having often attempted this manner, it was found to be only 115 or 120 feet high; but it is impossible to ascertain whether the pole was not stopped by some projection of the rock; for although when drawn up again the end of the cord was always wet, yet that is no proof, since the water which precipitates from the mountain, flies up again in foam to a very great height: for my own part, after having considered it on every side that I could examine it to advantage, I think that we cannot allow it to be less than 140 or 150 feet.
"Its figure is that of a horse-shoe, and its circumference is about 400 paces; but exactly in its middle, it is divided by a very narrow island, about half a quarter of a league long. It is true these two parts join again; that which was on my side, and of which I could only have a side view, has several projecting points, but that which I beheld in front, appeared to be perfectly even." The Baron has also mentioned a torrent, which, if not the offspring of his own invention, must fall into some channel upon the melting of the snow.
There is another cataract three miles from Albany, in the province of New-York, whose height is 50 feet perpendicular, and from which there arises a mist that occasions a faint rainbow.[325:A]
In all countries where mankind are not sufficiently numerous to form polished societies, the ground is more irregular, and the beds of rivers more extended, less equal, and often abound with cataracts. Many ages were required to render the Rhone and the Loire navigable. It is by confining waters, by directing their course, and by cleansing the bottom of rivers, that they obtain a fixed and regular course; in all countries thinly inhabited Nature is rude, and often deformed.
There are rivers which lose themselves in the sands, and others which seem to precipitate into the bowels of the earth: the Guadalquiver in Spain, the river Gottenburg in Sweden, and the Rhine itself, lose themselves in the earth. It is asserted, that in the west part of the island of St. Domingo there is a mountain of a considerable height, at the foot of which are many caverns, into which the rivers and rivulets fall with so much noise, as to be heard at the distance of seven or eight leagues.[326:A]
The number of rivers which lose themselves in the earth is very few, and there is no appearance that they descend very low; it is more probable that they lose themselves, like the Rhine, by dividing among the quantity of sand; this is very common to small rivers that run through dry and sandy soils, of which we have several examples in Africa, Persia, Arabia, &c.
The rivers of the north transport into the sea prodigious quantities of ice, which accumulating, form those enormous masses so destructive to mariners. These masses are the most abundant in the Strait of Waigat, which is entirely frozen over the greatest part of the year, and are formed by the great flakes which the river Oby almost continually brings there; they attach themselves along the coasts, and heap up to a considerable height on both sides, but the middle of the strait is the last part which freezes, and where the ice is the lowest. When the wind ceases to blow from the North, and comes in the direction of the Strait, the ice begins to thaw and break in the middle; afterwards it loosens from the sides in great masses, which are carried into the high sea. The wind, which all winter blows from the north over the frozen countries of Nova Zembla, renders the country watered by the Oby, and all Siberia, so cold, that even at Tobolski, which is in the 57th degree, there are no fruit trees, while at Sweden, Stockholm, and even in higher latitudes, there are both fruit trees and pulse. This difference does not proceed, as it has been thought, from the sea of Lapland being warmer than the Straits; nor from the land of Nova Zembla being colder than Lapland; but solely from the Baltic, and the Gulph of Bothnia, tempering the rigour of the north winds, whereas in Siberia there is nothing that can temperate the cold. It is a fact founded on experience, that it is never so cold on the sea coasts as in the inland parts of a country. There are plants which stand the winter in London exposed to the open air, that cannot be preserved at Paris; and Siberia, which is a vast continent, is for this reason colder than Sweden, which is surrounded on all sides by the sea.
The coldest country in the world is Spitzbergen: it lies in the 78th degree of north latitude, and is entirely formed of small peaked mountains; these mountains are composed of gravel, and flat stones somewhat like slate, heaped one on the other; which, it is affirmed by navigators, are raised by the wind, and increase so quick, that new ones are discovered every year. The rein-deer is the only animal seen here, which feeds on a short grass and moss. On the top of these little mountains, and at more than a mile from the sea, the mast of a ship was found with a pully fastened to one of its ends, which gives room to suppose that the sea once covered the tops of these mountains, and that this country is but of modern date; it is uninhabited, and uninhabitable; the soil of these small mountains has no consistence, but is loose, and so cold and penetrating a vapour strikes from it, that it is impossible to remain any length of time thereon.
The vessels which go to Spitzbergen for the whale fishery, arrive there early in the month of July, and take their departure from it about the 15th of August, the ice preventing them from entering the sea earlier, or quiting it after. Prodigious pieces of ice, 60, 70, and 80 fathoms thick are seen there, and there are some parts of it where the sea appears frozen to the very bottom[329:A]: this ice, which is so high above the level of the sea, is as clear and transparent as glass.
There is also much ice in the seas of North America, as in Ascension Bay, in the Straits of Hudson, Cumberland, Davis, Forbishers, &c. Robert Lade asserts that the mountains of Friezeland are entirely covered with snow, and its coasts with ice, like a bulwark, which prevents any approaching them. "It is, says he, very remarkable, that in this sea we meet with islands of ice more than half a mile round, extremely high, and 70 or 80 fathoms deep; this ice, which is sweet, is perhaps formed in the rivers or straits of the neighbouring lands, &c. These islands or mountains of ice are so moveable, that in stormy weather they follow the track of a ship, as if they were drawn along in the same furrow by a rope. There are some of them tower so high above the water, as to surpass the tops of the masts of the largest vessels."[330:A]
In the collection of voyages made for the service of the Dutch East India Company, we meet with the following account of the ice at Nova Zembla:--"At Cape Troost the weather was so foggy as to oblige us to moor the vessel to a mountain of ice, which was 36 fathoms deep in the water, and about 16 fathoms out of it.
"On the 10th of August the ice dividing, it began to float, and then we observed that the large piece of ice, to which the ship had been moored, touched the bottom, as all the others passing by struck against without moving it. We then began to fear being inclosed between the ice, that we should either be frozen in or crushed to pieces, and therefore endeavoured to avoid the danger by attempting to get into another latitude, in doing of which the vessel was forced through the floating ice, which made a tremendous noise, and seemingly to a great distance; at length we moored to another mountain, for the purpose of remaining there that night.
"During the first watch the ice began to split with an inexpressible noise, and the ship keeping to the current, in which the ice was now floating, we were obliged to cut the cable to avoid it; we reckoned more than 400 large mountains of ice, which were 10 fathoms under and appeared more than 2 fathoms above water.
"We afterwards moored the vessel to another mountain of ice, which reached above 6 fathoms under water. As soon as we were fixed we perceived another piece beyond us, which terminated in a point, and went to the bottom of the sea; we advanced towards it, and found it 20 fathoms under water, and 12 above the surface.
"The 11th we reached another large shelve of ice, 18 fathoms under water, and 10 above it.
"The 21st the Dutch got pretty far in among the ice, and remained there the whole night; the next morning they moored their vessel to a large bank of ice, which they ascended, and considered as a very singular phenomenon, that its top was covered with earth, and they found near 40 eggs thereon. The colour was not the common colour of ice, but a fine sky blue. Those who were on it had various conjectures from this circumstance, some contending it was an effect of the ice, while others maintained it to be a mass of frozen earth. It was about eighteen fathoms under water, and ten above."[332:A]
Wafer relates, that near Terra del Fuega he met with many high floating pieces of ice, which he at first mistook for islands. Some appeared a mile or two in length, and the largest not less than 4 or 500 feet above the water.
All this ice, as I have observed in the sixth article, was brought thither by the rivers; the ice in the sea of Nova Zembla, and the Straits of Waigat come from the Oby, and perhaps from Jenisca, and other great rivers of Siberia and Tartary; that in Hudson's Straits, from Ascension Bay, into which many of the North American rivers fall; that of Terra del Fuega, from the southern continent. If there are less on the North coasts of Lapland, than on those of Siberia, and the Straits of Waigat, it is because all the rivers of Lapland fall into the Gulph of Bothnia, and none go into the northern sea. The ice may also be formed in the straits, where the tides swell much higher than in the open sea, and where, consequently, the ice that is at the surface may heap up and form those mountains, which are several fathoms high; but with respect to those which are 4 or 500 feet high, they appear to be formed on high coasts; and I imagine that when the snow which covers the tops of these coasts melts, the water flows on the flakes of ice, and being frozen thereon, thus increases the size of the first until it comes to that amazing height. That afterwards, in a warm summer, these hills of ice loosen from the coasts by the action of the wind and motion of the sea, or perhaps even by their own weight, and are driven as the wind directs, so that they at length may arrive into temperate climates before they are entirely melted.
FOOTNOTES:
[306:A] See Racolta d'autori che trattano del motto dell' acque, vol. 1, page 123.
[312:A] See Keil's Examination of Burnet's Theory, page 126.
[313:A] See Shaw's Travels, vol. ii, page 71.
[317:A] See Boyle, vol. iii. page 217.
[321:A] See Ovington's Travels, vol. ii. page 290.
[323:A] See Phil. Trans. Abr. vol. vi. part ii. page 119.
[325:A] Phil. Trans. vol. vi. part ii. page 19.
[326:A] See Varenii Geograph. gen. page 48.
[329:A] In contradiction to this idea it is now a generally received opinion, that the mountains of ice in the North and South Seas are exactly the same depth under as they are height above the surface of the water.
[330:A] See the Voyages of Lade, vol. ii, page 305, &.
[332:A] Voyage of the Dutch to the North, vol. 1, 3. Page 49.
_END OF THE FIRST VOLUME._
TRANSCRIBER'S NOTES
Variations in spelling and hyphenation have been left as in the original.
The following changes have been made to the original text:
Page vi: It would have been singular[original has "singuar"]
Page 9: moon, which are the causes of["of" missing in original] it
Page 23: these particles[original has "particels"] of earth and stone
Page 31: In a word, the materials[original has "mateterials"] of the globe
Page 37: has occurred, and in my opinion[original has "oppinion"] very naturally
Page 51: These[original has "these"] could not have been occasioned
Page 74: in the regions of the sky [original has "fky"]
Page 94: that fire cannot[original has "connot"] subsist
Page 94: planets at[original has "as"] the time of their quitting the sun
Page 97: there will be detached[original has "detatched"] from its equator
Page 104: which are as 229 to 230.[period missing in original]
Page 155: ARTICLE VI.[original has "VII."]