"It is now considered that there is clear geological proof that the Fall once existed at Queenston. The 710,000 tons of water which each minute pour over the precipice of the Niagara, are estimated to carry away a foot of the cliff every year; therefore we must suppose a period of 20,000 years occupied in the recession of the cataract to its present site."--Lyell's _Geology_.] [Footnote 135: "The mouth of the whirlpool is more than 1000 feet wide, and in length about 2000. Mr. Howison, in his sketches of Upper Canada, says that the current of the river has formed a circular excavation in the high and perpendicular banks, resembling a bay. The current, which is extremely rapid, whenever it reaches the upper point of this bay, forsakes the direct channel, and sweeps wildly round the sides of it; when, having made this extraordinary circuit, it regains its proper course, and rushes with perturbed velocity between two perpendicular precipices, which are not more than 400 feet asunder. The surface of the whirlpool is in a state of continual agitation. The water boils, mantles up, and wreaths in a manner that proves its fearful depth, and the confinement it suffers; the trees that come within the sphere of the current are swept along with a quivering, zigzag motion, which it is difficult to describe. This singular body of water must be several hundred feel deep, and has not hitherto been frozen over, although in spring the broken ice that descends from Lake Erie descends in such quantities upon its surface, and becomes so closely wedged together, that it resists the current, and remains till warm weather breaks it up. The whirlpool is one of the greatest natural curiosities in the Upper Province, and its formation can not be rationally accounted for."--Martin's _History of Canada_, p. 139.]