The Pacific and the Atlantic cannot be the cause; we must seek it elsewhere. To the westward of Huron, on the borders of Superior, the land is rocky and elevated; but it attains only enormous alt.i.tudes at such a distance on the rocky Andean chain as to render it improbable that those mountains exert immediate influences on the lakes. The Atlantic also is too far distant, and very elevated land intervenes to intercept the rising vapours. On the north, high lands also exist; and the snows scarcely account for it, as the whole of North America near these inland seas is alike covered every year in winter.

The north-east and the south-west winds are the prevalent ones, and a slight inspection of the maps will suffice to show that those compa.s.s bearings are the lines which the lakes and valleys of Northern America a.s.sume.

In 1845, the lakes began suddenly to diminish, and to such a degree was this continued from June to December, when the hard frosts begin, that, at the commencement of the latter month, Lake Ontario, at Kingston, was three feet below its customary level, and consequently, in the country places, many wells and streams dried up, and there was during the autumn distress for water both for cattle and man, although the rains were frequent and very heavy.

Whence, then, do the lakes receive that enormous supply which will restore them to their usual flow?--or are they permanently diminishing?

I am inclined to believe that the latter is the case, as cultivation and the clearings of the forest proceed; for I have observed within fifteen years the total drying up of streamlets by the removal of the forest, and these streamlets had evidently once been rivulets and even rivers of some size, as their banks, cut through alluvial soils, plainly indicated.

The lakes also exhibit on their borders, particularly Ontario, as Lyell describes from the information of the late Mr. Roy, who had carefully investigated the subject, very visible remains of many terraces which had consecutively been their boundaries.

It is evident to observers who have recorded facts respecting the lakes, that but a small amount of vapour water is deposited by northeasterly winds from the Gulf of St. Lawrence, the great estuary of that river, of which the lakes are only enlargements, as the wind from that region carries the cloud-ma.s.ses from the lakes themselves direct to the valley of the Mississippi. For it meets with no obstacle from high lands on the western littorale, which is low. A north-east gale continues usually from three to six days, and generally without much rain; but all the other winds from south to westerly afford a plentiful supply of moisture. Thus a shift of wind from north-east to north and to north-west perhaps brings back the vapour of the great valley of the gulf, reduced in temperature by the chilly air of the north and west. If then an easterly gale continues for an unusual time, the basin of the Canadian lakes is robbed of much of its water, which pa.s.ses to the rivers of the west, and is lost in the gulf of Mexico, or in the forest lakes of the wild West.

Perhaps, therefore, whenever a cycle occurs in which north-east winds prevail during a year or a series of years, the lakes lose their level, for, their direction being north-east and south-west, such is the usual current of the air; and therefore either north-east or south-westerly winds are the usual ones which pa.s.s over their surface.

The parts of the great inland navigation which suffer most in these periodical depressions are the St. Clair River and the shallow parts of those extensions of the St. Lawrence called Lakes St. Francis and St.

Peter, which in the course of time will cause, and indeed in the latter already do cause, some trouble and some anxiety.

The north winds, keen and cold, do not deposit much in the valley of the lakes, whose southern borders are usually too low also to prevent the pa.s.sage of rain-bearing clouds.

From that portion of the dividing ridge between the valleys of the St.

Lawrence and Mississippi, only seven miles from Lake Erie, says an American writer, there is to Fort Wayne, at the head of the Maumee river, one hundred miles from the same lake, a gradual subsidence of the land from 700 to less than 200 feet.

From Fort Wayne westward this dividing ridge rises only one hundred and fifty feet, and then gradually subsides to the neighbourhood of the south-west of Lake Michigan, where it is but some twenty feet above the level of that water.

The basin of the Mississippi, including its great tributary streams, receives therefore a very great portion of the falling vapour, from all the winds blowing from north to north-east.

The same reasoner agrees with the views which I have expressed respecting the probability of the supply to raise the level, which must be the great feeder derived from the south and south-westward invariably rainy winds, when of long continuance, in the basin of the St.

Lawrence, and generated by the gulf stream in its gyration through the Mexican Bay, being heaped up from the trade wind which causes the oceanic current, and forces its heated atmosphere north and north-east, by the rebound which it takes from the vast Cordilleras of Anahuac and Panama; thus depositing its cooling showers on the chain of the fresh water seas of Canada, condensed as they are by the natural air-currents from the icy regions of the western Andes of Oregon, and the cold breezes from the still more gelid countries of the north-west.

The American topographical engineers, as well as our own civil engineers and savans, have accurately measured the heights and levels of the lakes, which I have already given; but one very curious fact remains to be noticed, and will prove that it is by no means a visionary idea that, from the great island of Cuba, which must be an English outpost, if much further annexation occurs, voyages will be made to bring the produce of the West Indies and Spanish America into the heart of the United States and Canada by the Mississippi and the rivers flowing into it, and by the great lakes; so that a vessel, loading at Cuba, might perform a circuit inland for many thousand miles, and return to her port _via_ Quebec.

From the Gulf of Mexico to the lowest summits of the ridge separating the basin of the Mississippi from that of the St. Lawrence or great lakes, the rise does not exceed six hundred feet, and the graduation of the land has an average of not more than six inches to a mile in an almost continuous inclined plane of six thousand miles. The Americans have not lost sight of this natural a.s.sistance to form a communication between the lakes and the Mississippi.

My attention has been drawn to the subsidence of the waters of the lakes of Canada by the unusual lowness of Ontario, on the banks of which I lived last year, and by reading the statement of the American writer above quoted, as well as by the fact that in the Travels of Carver, one of the first English navigators on these mediterraneans, who states that a small ship of forty tons, in sailing from the head of Lake Michigan to Detroit, was unable to pa.s.s over the St. Clair flats for want of water, and that the usual way of pa.s.sing them eighty years ago was in small boats. What a useful thing it would have been, if any scientific navigators or resident observers had registered the rise and fall of the lakes in the years since Upper Canada came into our possession! An old naval officer told me that it was really periodical; and it occurred usually, that the greatest depression and elevation had intervals of seven years. Lake Erie is evidently becoming more shallow constantly, but not to any great or alarming degree; and shoals form, even in the splendid roadstead of Kingston, within the memory of young inhabitants.

An American revenue vessel, pierced for, I believe, twenty-four guns, and carrying an enormous Paixhan, grounded in the autumn of last year on a shoal in that harbour, which was not known to the oldest pilot.

By the bye, talking of this vessel, which is a steamer built of iron, and fitted with masts and sails, the same as any other sea-going vessel, can it be requisite, in order to protect a commerce which she cannot control beyond the line drawn through the centre of the lakes, to have such a vessel for revenue purposes? or is she not a regular man-of-war, ready to throw her sh.e.l.ls into Kingston, if ever it should be required?

At least, such is the opinion which the good folks of that town entertained when they saw the beautiful craft enter their harbour.

The worst, however, of these iron boats is that two can play at sh.e.l.ling and long shots; and gunnery-practice is now brought to such perfection, that an iron steamer might very possibly soon get the worst of it from a heavy battery on the level of the sea; for a single accident to the machinery, protected as it is in that vessel, would, if there was no wind, put her entirely at the mercy of the gunners. The old wooden walls, after all, are better adapted to attack a fortress, as they can stand a good deal of hammering from both shot and sh.e.l.ls.

But to revert to matters more germane to the lakes.

Volney, the first expounder of the system of the warm wind of the south supplying the great lakes, has received ample corroboration of his data from observation. The fact that the deflection of the great trade-wind from the west to a northern direction by the Mexican Andes Popocatepetl, Istaccihuetl, Naucampatepetl, &c., whose snowy summits have a frigid atmosphere of their own, is proved by daily experience.

Whenever southerly winds prevail--and, in the cycle of the gyration of atmospherical currents, this is certain, and will be reduced to calculation--the great lakes are filled to the edge; and whenever northern and northeasterly winds take their appointed course, then these mediterraneans sink, and the valley of the Mississippi is filled to overflowing.

But the most curious facts are, that the different lakes exhibit different phenomena. The Board of Public Works of Ohio states that, in 1837-38, the quant.i.ty of water descending from the atmosphere did not exceed one-third of that which was the minimum quant.i.ty of several preceding years.

Ontario, from the reports of professional persons, has varied not less than eight feet, and Erie about five. Huron and Superior being comparatively unknown, no data are afforded to judge from; but what vast atmospheric agencies must be at work when such wonderful results in the smaller lakes have been made evident!

People who live at the Niagara Falls, and I agree with them in observations extending over a period since 1826, believe that these Falls have receded considerably; and, although I do not enter into the mathematical a.n.a.lysis of modern geologists respecting them, as to their constant retrocession, believing that earthquake split open the present channel, yet I have no doubt that the level of Lake Erie is considerably affected by the diminution of the yielding shaly rocks of their foundation. Earthquake, and not retrocession, appears to me, who have had the singular advantage, as a European, of very long residence, to have been the cause of that great chasm which now forms the bed of the Niagara, from the Table Rock to Queenston, in short, a rending or separating of the rocks rather than a wearing; and this is corroborated by the many vestiges of great cataracts which now exist near the Short Hills, the highest summit of the Niagara frontier, between Lakes Erie and Ontario, as well as by the great natural ravine of St. David's. But this is a subject too deep for our present purpose, and so we shall continue to treat of the Great Lakes in another point of view.

Chemically considered, these lakes possess peculiar properties, according to their boundaries. Superior is too little known to speak of with certainty--Huron not much better--but Erie, and particularly Ontario, have been well investigated. The waters of these are pure, and impregnated chiefly with aluminous and calcareous matter, giving to the St. Lawrence river a fresh and admirable element and aliment.

The St. Lawrence is of a fine cerulean hue, but, like its parent waters of Erie and Ontario, rapidly deposits lime and alumine, so that the boilers of steam-vessels, and even teakettles, soon become furred and incrusted. The specific gravity of the St. Lawrence water above Montreal is about 100038, at the temperature of 66, the air being then 82 of Fahrenheit. It contains the chlorides, sulphates, and carbonates, whose bases are lime and magnesia, particularly and largely those of lime, which accounts for the rapid depositions when the water is heated.

A very accurate a.n.a.lysis gives, at Montreal, in July, atmospheric air in solution or admixture 446 per cent; for a quart of this water, 57 inches cubic measure, evaporated to dryness, left 2.87 solid residue.

Grains.

Sulphate of magnesia 062 Chloride of calcium 038 Carbonate of magnesia 027 Carbonate of lime 129 Silica 031 ---- 287

The waters of the Ottawa, flowing through an unexplored country, are of a brown or dark colour. Their specific gravity is only (compared to distilled water) as 10024 at 66, the temperature of the air in July being 82.

The 57 cubic inches of this water gave

099 sulphate of magnesia.

060 chloride of lime.

107 carbonate of magnesia.

017 carbonate of lime.

031 silica.

---- 287

The difference of the colours of these waters is so great, that a perfect line of distinction is drawn where they cross each other; and there can be no doubt that it is caused by the reflection of the rays of light from the impregnation of different saline quant.i.ties.

Thus as, in the old world, the waters of the Shannon are brown, and Ireland, speaking generally, as Kohl says, is a "brown" country;[8] so, in Upper Canada, St. Lawrence and the lakes are blue and green; and in Lower Canada, St. Lawrence and the Ottawa are brown of various shades, a very slight alteration of the chemical components reflecting rays of colour as forcibly and perceptibly as, in like manner, a very slight change of component parts develops sugar and sawdust. Nature, in short, is very simple in all her operations.

[Footnote 8: Canada is a blue country; for, a very short distance from the observer, the atmosphere tinges everything blue; and the waters are chiefly of that colour, the sky intensely so.]

Before we proceed to the lower extremity of these wonderful sheets of water again, let us just for a moment glance at what is about to be achieved upon their surfaces, and place the Sault of St. Marie or St.

Mary's Rapids, which separate Superior from Huron, before an Englishman's eyes. There at present nothing is talked of but copper mines and silver or argentiferous copper ores.

The Falls of St. Mary are only rapids of no very formidable character, the exit of Lake Superior into Lake Huron. Fifteen miles from the end of the Great Lake, as Superior is called, are the American village of St.

Mary and the British one of the same name, on the opposite bank of the River St. Mary.

The Americans have so far strengthened their position, that there is a sort of fort, called Fort Brady, with two companies of regulars; and in and about the village are scattered a thousand people of every possible colour and origin, a great portion being, of course, half-breeds and Indians. The American Fur Company has also a post at this place, one of the very few remaining; for the fur trade in these regions is rapidly declining by the extirpation of the animals which sustained it.

The American government have projected a ship ca.n.a.l to avoid these rapids; and, if that is completed, a vast trade will soon grow up.

About a mile above the village is the landing-place from Lake Superior, at the head of the rapids; there the strait is broad and deep; but, until steamers are built, sailing vessels suffer the disadvantage of being moveable out of the harbour by an east wind only, and this wind does not blow there oftener than once a month. It is probable that a proper harbour will be constructed at the foot of the lake, fifteen miles above.

These rapids have derived their French name _Sault_ from their rushing and leaping motion; but they are very insignificant when compared to the Longue Sault on the St. Lawrence, as the inhabitants cross them in canoes.

I cannot describe them more minutely than Mrs. Jameson has done in her "Summer Rambles." She crossed them, and must have experienced some trepidation, for it requires a skilful voyageur to steer the canoe; and it is surprising with what dexterity the Indian will shoot down them as swiftly as the water can carry his fragile vessel. The Indians, however, consider such feats much in the same light as a person fond of boating would think of pulling a pair of oars, or sculling himself across the current of a rivulet. I was once subjected to a rather awkward exemplification of this fact. Being on a hurried journey, and expecting to be frozen in, as it is called, before I could terminate it; I hired an Indian and his little canoe, just big enough to hold us both, and pushed through by-ways in the forest streams and portages. We were paddling merrily along a pretty fair stream, which ran fast, but appeared to reach many miles ahead of us; when, all of a sudden, my guide said, "Sit fast." I perceived that the water was moving much more rapidly than it had hitherto done, and that the Indian had wedged himself in the stern, and was steering only with the paddle. We swept along merrily for a mile, till "The White Horses," as the breakers are called, began to bob their heads and manes. "Hold fast!" e.j.a.c.u.l.a.t.ed the Red Man. I laid hold of both edges of the canoe, firm as a rock, and in a moment the horrid sound of bursting, bubbling, rushing waters was in mine ears; foam and spray shut out every thing; and away we went, down, down, down, on, on, on, as swift as thought, until, all of a sudden, the little buoyant piece of birch-bark floated like a swan upon the bosom of the tranquil waters, a mile beyond the Fall, for such indeed it might be called, the absolute difference of level having been twelve feet.

When at ease again, I looked at the imperturbable savage and said, "What made you take the Fall? was not the _detour_ pa.s.sable?"--"Yes, suppose it was! Fall better!"--"But is it very dangerous?"--"Yes, suppose, sometime!"--"Any canoes ever lost there?"--"Yes, sometime; one two, tree days ago, there!" pointing to a large rock in the middle of the narrowest part above our heads.--"Did you come down there?"--"Yes, suppose, did!"

Then, thought I to myself, I shall not trust my body to your guidance in future without knowing something of the route beforehand; but I afterwards got accustomed to these taciturn sons of the forest.