flowed over these projecting bare rocks, in descending, spread out into magnificent festoons. The beautiful feature which I formerly saw has disappeared. To this it may be said, that the waters of Lake Erie were unusually low in 1846, and this may account for the retreat. But I would reply, that no diminution was indicated by the banks of the river. I was told in 1829, by one who had resided there forty years, that a difference of level was perceptible only when a strong southwest wind sweeps over the wide expanse of Lake Erie, driving its waters into the mouth of the river. Not having made a very careful outline of the edge of the American fall, I am not prepared to say, whether any material change had taken place, with the exception of its being apparently more broken in the centre, where the cutting process appears to go on with great activity. It is stated by residents there, that a considerable alteration had taken place, from the falling of masses of limestone rock from the middle of the cataract. That a constant change is in progress no one can doubt who carefully examines for himself as he wanders over this wonderful scene. I was particularly impressed with its magnificence while making a drawing of what is called the cave, situated half a mile below the ferry on the American side. This cave or ledge of bare rock, has just the appearance that the rocks over which the American falls are now precipitated, would present, if the waters were suddenly withdrawn. The same broken outline appears in both instances, giving evidence that in each case the most violent action had been in the centre. When the cataract was here, the space between the American fall and the commencement of the cave', was in all probability, an island, presenting a similar appearance to what the falls now have. There is still a small stream flowing down the precipice where once a mighty torrent fell.

What surprised me much on my second visit, was the comparative stillness in which the mighty work of discharging the surplus waters of so many inland seas down a precipice of one hundred and eighty feet was carried on. In father Hennepin's curiously interesting description of this "vast and prodigious cadence of water," he represents himself or his friends as being so overcome by the noise, that the hands were applied to the ears by way of dampers. The marvel to me is, that they make so little noise. It cannot be denied, however, that the state of the atmosphere and direction of wind, have much to do in regulating the sound produced by the fall of this immense body of water.

After these preliminary remarks, I will now confine myself more particularly to the object for which this communication was undertaken, which was to offer some observations on the whirlpool, as well as on the rapids below the falls, and to assign a probable cause for their existence. If in doing this I should be

able to add any thing to the interest which will ever be felt by those who visit the falls, and its vicinity, my labor will not be altogether in vain.

Fig. 1.

A Birds-eye View, or Map of the Ravine from the Falls of Niagara to the Whirlpool.

K. Canada.-U. United States.-The dotted lines represent the outline of the ancient valley, partly filled with drift, H.-F. Ravine.-C. Whirlpool.-B. Summer-house.-D, E. Quartzose rock seen below the surface of the water.

Having made several visits to the whirlpool, taking sketches from points which I thought most desirable, I found that each visit increased my admiration and wonder. A general idea of its situation may be had by reference to the drawing, fig. 1, giving a birdseye view of the country from the falls to the whirlpool, a distance of three miles. Perhaps I shall make myself better understood by giving a description of the ravine from A to B. The width. of the river at the ferry is about eleven hundred and forty feet. The height of the rocks, one hundred and eighty feet. On the verge of the precipice, a little below the American falls, there is a path which leads directly to the Summer-house, B, situated immediately above the whirlpool; this path continues close to the edge of the precipice. About half a mile down, we come to the cave' before alluded to-a bare rock on which nothing grows-a place of deep interest to the traveller as he stands upon this ancient bed of a former lateral torrent.

The river below the falls moves majestically along without a ripple, having the appearance of dark bottle-green marble, varying

at times into blue, with yellowish and greenish veins, the latter due to the foam which seems as if imbedded as it streams down in long wavy lines. This solid representation of water, gave an additional novelty to the scene. About one mile from the falls the sides of the ravine gradually converge, diminishing of course the width of the river. Half a mile still lower,* following along by the edge of the precipice, the stream takes a gentle turn to the left. The water on each side is seen to ripple; then commences a chain of waves preceded by deep furrows, which converge to a point in the middle of the river, indicating not only the rapidity of the current, but also the upheaving of the waters, rising, as has been ascertained by measurement, eleven feet above the level at the sides; after this, it is broken into foam and spray, and dashing on with impetuous fury, pursues its wild career for about a mile, then rushes with the swiftness and violence of an avalanche into a wide circular area of one hundred and twenty acres in extent. Then, suddenly, as by an unseen power, it is calmed down, and in silence sweeps round in eddying circles; these circles glide into curves which swell round this vast amphitheatre in gentle undulations, as if gathering strength for its last conflict through the narrow portal which leads to its oblivion in the waters of Ontario.

While standing on the precipice at the Summer-house, (B, fig. 1,) which overlooks the whirlpool, my attention was particularly directed to the place where the waters enter the whirlpool, where I could distinctly see the rocks projecting for a considerable distance from the Canada side towards the centre of the current, not many feet below the surface of the water, contracting very considerably the space through which the waters apparently escape. The curved line, DE, indicates this projection. There was something impressively grand in the whole scene as contemplated from this point. The drainage of four great lakes covering an area of about 135,000 square miles, escapes at the northern extremity of Lake Erie through a channel, (as stated by Mr. Allen, from measurements by Mr. E. R. Blackwell,) seventeen hundred feet in width, thirty-two feet in depth, running at the rate of six miles an hour, equal to 22,440,000 cubit feet, weighing 701,250 tons, flowing every minute ;t-here the whole is confined to a breadth not exceeding two hundred and twenty-five feet! the distance from rock to rock, as I was informed by the proprietor

* I observed a steamboat intended to ply between a landing place, which had been constructed at great expense down the precipice to the water's edge, at the base of the falls, &c.; but on trial, the engine had not power sufficient to contend with the current. It is to be hoped the project will be forever abandoned. In case of accident to the machinery, there is nothing to prevent the destruction of the boat in the rapids.

† Am. Jour. of Sci., Vol. xlvi, p. 71.

of the grounds. The question naturally arises, how is it possible for this immense volume of water to escape through so narrow a defile, and then suddenly to become comparatively sluggish in the whirlpool. On referring to Mr. Lyell's admirable work on America which I had with me, and examining the section of the strata from Niagara to the whirlpool, which Mr. L. had taken from Mr. Hall's geological Report on the Geology of New York, it occurred to me that a satisfactory explanation might be given. The projecting rock under the water is unquestionably the hard quartzose sandstone, and underneath this lies a very thick bed of soft red shale. A short distance before the waters enter the whirlpool, this floor of hard sandstone rock is broken through, and the resistless torrent has made itself a passage underneath this rock, on each side of the ravine, and it is by this excavation that the waters escape. This perhaps will be made more apparent, when explaining in the sequel the supposed origin of the whirlpool. The section, fig. 2, is principally from Lyell, in which I have introduced the river, whirlpool, and the ancient lateral valley, (H,) filled with drift. In the following remarks, great stress is laid on the relative hardness of the rocks which compose the Niagara group: consisting as it does, of hard limestone, calcareous shale, soft shaly sandstone, and of quartzose sandstone. Had all the strata consisted of solid limestone, as I remarked in the communication before re

the dotted lines, I, F, G, in fig. 1. very soft.-H. Valley filled up with drift, marked H in fig. 1.-W. Whirlpool, which forms deep lateral valley as represented by W in fig. 4, and by F, G. Compact limestone resting on soft beds of shales.-3. Red shaly sandstone-very friable drift.-2. Quartzose sandstone extremely hard.-1. Thick bed of shale,

the terminus to the

S

ferred to, there is great reason to believe that the erosive action of the water would have been very slow, and many generations might have passed without any sensible change; but the vast mass of waters breaking with inconceivable force on the softer shale which forms the base of the hard rock, the foundation is thus undermined, the harder rocks fall down for want of support,' thus causing the various changes between turbulence and tranquillity which take place in the river in its course from the falls to the outlet at Queenston.

Taking it for granted that the cataract was once at the precipice at Queenston, it will be seen by reference to the section, fig. 2, that, owing to the inclination of the strata, the falls would be considerably higher than they are at present; thus exposing to view several beds of shale, limestones, and sandstones not found at the falls. The lowest (No. 1) is a very thick stratum of friable shaly red sandstone, through which the river ploughs its way. The river at Queenston, as we are informed by Mr. Allen, before referred to, is one hundred and sixty feet in depth. This depth is sufficient to entomb the huge fragments of the harder rocks, as they would gradually fall down by the erosive, undermining process continually going on by the descending flood, without causiug any agitation of the surface. It will be seen from the dip of the strata, that as the falls retrograde, the hard quartzose rock would be at the base of the falls, and in time cease to be broken through by the cataract; as the retrocession advanced, the waters would have to flow over this hard rock. The superincumbent limestone falling on this hard pavement would cause a great impediment to the escape of the water, which would give rise to the rapids.

From the whirlpool to what is called the Devil's hole, and for a considerable distance below, the river rushes with great impetuosity, when it gradually subsides, and then moves on in silent grandeur towards the lake. On crossing the river at Lewiston, and ascending the hill near Brock's monument, I was agreeably surprised on beholding the singular and furrowed appearance of the ground. It was smooth on the surface, but shaped into knolls and ravines, having the appearance of a mountainous country in miniature-hills and valleys-but without water; and this all excavated out of the hard limestone rock. This appearance gave me satisfactory evidence that the waters of the lakes once rushed over the ground on which I was walking.

The whirlpool as seen on the Canada side of the river, presents many more points of interest than on the American, independently of the curiosity excited by Mr. Lyell's discovery of a deep lateral valley filled with drift, which he traced from the whirlpool to St. David's; Mr. Hall having first suggested the idea that it might be connected with the opening at that place.