LETTER IV. Brief Account of the great Lakes which supply the River Niagara. Lake Superior: its Islands, Rivers, &c. River St. Marie: its only Outlet. Opinion, that there are subterranean Outlets, examined. Lake Huron. Lake Michigan. Island of Michilimackinac. Huron River. Lake St. Clair. Lake Erie. Evidence, that the Waters of these Lakes are lower than they formerly were. DEAR SIR; BEFORE I commence my account of the river and falls of Niagara, it will not be amiss to describe, summarily, the great chain of lakes, whose waters are conveyed to the ocean through this channel. Without a just apprehension of the extent of this singular collection of waters, it will not be easy for you to conceive, or even to admit, correct views of the importance and splendour of the river St. Lawrence. The first and westernmost of these inland seas is Lake Superior. Carver, whose accounts, so far as they have been examined, have, notwithstanding the discredit at first attached to them, been found to be remarkably just and accurate, and who coasted the north-eastern and north-western shores of this lake near twelve hundred miles, informs us, that its whole circuit measures more than sixteen hundred: an estimate somewhat larger than that of M'Kensie. It lies between 46° and 49° north latitude, and between 84° and 93° west longitude from London. So far as he had opportunities of examining, its shores are rough, rocky, and mountainous. The water is remarkably transparent; so that, in his language, over a depth of six fathoms, his canoe, instead of appearing to rest on the water, seemed as if suspended in the air. In the summer it is warm at the surface, but at a small depth is very cold. Lake Superior contains many islands, and among them five of a considerable size, Round, Pont-Chartrain, Philippeaux, Mirapau, and Royal; the last one hundred miles in length and forty in breadth. Neither of these islands has hitherto been explored. Some of them, regarded by the Indians as sacred places, are holden in high veneration. About forty small rivers enter this lake; and three of a superior size: the Nipegon, the Michipicoton, and the St. Louis. The first on the north-eastern, and the second on the north-western side. The third, whose springs are the most remote waters of the St. Lawrence, discharges itself at the south-western angle. To the eye this lake, except at the two angles, is an ocean: the view being literally boundless. Like the ocean also, it is frequently, and furiously, agitated by storms, which are in the highest degree dangerous to navigators. Virgin copper is found in many places on the shore, and on many of the small islands, particularly on those which are near the eastern coast. A small river, a little eastward of the Nipegon, descends, just before its entrance into the lake, over a perpendicular precipice, more than six hundred feet in height. Lake Superior abounds in fish of various kinds, the principal of which are the trout, the white-fish, and the sturgeon. The channel through which the waters of this vast reservoir are emptied into the Huron is the river St. Marie, which in one place is not more than six feet in depth. By Carver, and by others who have followed him, it is supposed, that, after making the utmost allowance for the quantity of water evaporated from its surface, the St. Marie is an insufficient channel for the conveyance of the superabundant waters of the lake; and that, therefore, they are drawn off by one or more subterraneous passages. Permit me to examine this opinion. That subterraneous passages exist, which descend to the centre, or pass circuitously round the globe, or any considerable part of it, will hardly be imagined. If they terminate at any moderate distance beneath the surface, they must for thousands of years have been filled, and certainly can admit no more supplies from the lake. If they break through the surface, the effusion of water from the orifice must be too extraordinary to have escaped observation. If the passage terminates at the bottom of one of the neighbouring lakes (say Huron, or Michigan), the nearest, and therefore the most promising resorts in this investigation, the water above and around the opening would boil with a force, which must detect the fact; since every part of these lakes is continually wandered over, both by the Indians and the whites. The only remaining supposition is, that these conduits open in the bed of the St. Lawrence; where the effect would be still more visible than in either of the lakes, or in the ocean; above whose surface that of Lake Superior is elevated at least a thousand feet. The pressure of a column of this height, to speak in very moderate terms, would create such a disturbance of the surface of the ocean, as must long since have been marked by many of the numberless vessels, which ply continually in every part of the Northern Atlantic. Such a phenomenon must have been universally known throughout the eighteenth century, and probably through the latter half of the seventeenth. At the same time, such a subterranean stream, proceeding from this lake, would occasion a violent whirlpool on the surface; and this must have been observed by some or other of the numerous voyagers, who pass over it every summer; but nothing of this nature has been seen. On the contrary, the waters in calm weather are perfectly smooth and quiescent. That the river St. Marie is a sufficient outlet for these waters, sufficient I mean to carry off all its supplies, except what are exhausted by evaporation, I have not a single doubt. In the year 1810, a lake in the township, either of Glover or of Greensborough, and county of Orleans, in the state of Vermont, broke through its barriers, and emptied its waters into the Lake Memphremagog. The bed was left entirely vacant. Before this event a mill-stream ran out of it into the river La Moille: a stream now runs from its bed into Barton river, furnished by the same springs, which, originally subjacent, supplied the waters of the lake. The difference between these two streams is imperceptible. From this fact it appears, that the little stream, which formerly carried the waters of this lake into the La Moille, apparently disproportioned to the quantity of water, conveyed off whatever was superfluous, or in other words whatever was supplied by the springs. This lake was about two miles and a half in length, a mile in breadth, and one hundred and ninety-seven feet in depth. The quantity of water which flowed into this bed, and accumulated this mass, or, in other words, the supplies necessary to form such an accumulation, was incomparably less than we have been accustomed to believe*. The whole mass of Connecticut river often runs during a part of the summer in a channel at Bellows'-Falls, at times * From the New-England Palladium, Friday, June 22d, 1810: -- "Vermont, Montpelier, June 9th, 1810. "On the 6th inst. the large pond, in the north-east part of Greensborough, which formed the head of the river La Moille, burst its bounds, and emptied itself into Lake Memphremagog, distant about twenty-five miles. This pond, which was about two and a half miles in length, one in breadth, and about one hundred feet in depth, was situated on the Green Mountain range, and was considerably higher than the surrounding country. At the distance of about forty rods was another smaller pond; on the outlet of which stood a number of mills. The perpendicular height of the former above the latter, was about one hundred feet. It had long been contemplated to make a communication between them, in the expectation that it would greatly benefit the mills below the small poud. On the day above mentioned a number of the inhabitants of Wheelock, Sheffield, Glover, and Barton, met for the purpose of digging a channel, and commenced their operations on the brow of a descent, a few rods from the large pond. They soon finished a channel, five or six feet in depth. As this was filled, the ground, which was a kind of quicksand, began to sink, and the pressure soon produced a chasm of upwards of one hundred feet in depth, and eighteen or twenty rods in breadth. The water issued from the pond with such impetuosity, that it was completely drained in one hour. The ground sunk so suddenly that the workmen had scarcely time to save themselves; and one of them sunk five or six feet, but was so fortunate as to escape by laying hold on the root of a tree. The water rushed into the lower pond, and thence proceeded through a forest of heavy timber, six miles to Barton river, carrying with it every thing in its way. It then took the course of Barton river, repeating the same devastation till it reached Lake Memphremagog. Farms, which lay on the banks of this river, were covered ten or twelve feet deep; and two saw-mills, a grist-mill, and a blacksmith's shop, five bridges, and a great number of sheep, were swept into the lake. "The scene which it presented was awful. The vallies were filled up, and the hills were levelled. The earth trembled throughout a circuit of many miles. The noise, which was heard throughout a great distance, was at first supposed to be thunder; but, as the sky was unclouded, was speedily believed to be that of an earthquake. Happily no lives were lost." not more than twenty-five feet in breadth, and, so far as I am able to judge, of not more than four or five feet in depth; and yet, at a small distance above and below, the river is forty rods in breadth, probably not less than six or eight in depth, and runs with a strong current. Not a man living would, I presume, believe it possible for such a mass of water to descend through this crevice, for it is little more, without being compelled by ocular demonstration. All the supplies furnished by rivers to Lake Superior, except those derived from subjacent springs, amount to a quantity not very considerable. Not a small part of them must be drawn off by evaporation; for the remainder the St. Marie, must, I think, be an ample channel, when I consider the facts mentioned above. In this opinion I am confirmed by observing the drains of other lakes; few if any of which bear any such proportion, as a priori we should expect, to the body of waters which they contain. The Sorelle would be thought a less river than would be formed by the union of Otter creek, Onion river, the La Moille, the Misciscoui, Pulteney river, and the outlet at Lake George. Yet Lake Champlain receives a multitude of streams of a smaller size, besides what is furnished by springs. The outlet of Lake George, also, is a little stream. The same may be said of many, perhaps of almost all others. The Caspian has no outlet; although it receives the waters of the Volga, the Ural, the Kur, the Tedjon, and several other considerable rivers. It is said, that the surface of Lake Superior is evidently about six feet lower than it was at some former period. The proof alleged is the appearance of the rocks, and other parts of the shore, which to this height bear evident marks of having been once covered by water. Aside from this evidence the opinion may be received without difficulty. The St. Marie is undoubtedly continually lowering its bed, insensibly indeed, but certainly. That in a long progress of years it should have worn it down the depth specified can excite no surprise. Just at the head of the St. Marie there is a remarkably rich prospect of the river, the lake, its islands, the points, and other parts of the neighbouring shores. Lake Huron, into which the St. Marie enters, is the second |
