[Footnote 130: "The total area of the four great lakes which pour forth their waters to the ocean over the Falls of Niagara is estimated at 100,000 square miles."--Montgomery Martin.] [Footnote 131: Colonel Bouchette observes, that, according to the altitude of the sun, and the situation of the spectator, a distinct and bright iris is soon amid the revolving columns of mist that soar from the foaming chasm, and shroud the broad front of the gigantic flood. Both arches of the bow are seldom entirely elicited, but the interior segment is perfect, and its prismatic hues are extremely glowing and vivid. The fragments of a plurality of rainbows are sometimes to be seen in various parts of the misty curtain.] [Footnote 132: Symptoms of the Falls are discerned from a vast distance. From Buffalo, twenty miles off, two small fleecy specks are distinctly seen, appearing and disappearing at intervals. These are the clouds of spray arising from the Falls; it is even asserted that they have been seen from Lake Erie, a distance of fifty-four miles.--Weld, p. 374.] [Footnote 133: The sound of the Falls appears to have been heard at the distance of twenty or even forty miles: but these effects depend much on the direction of the wind, and the tranquil or disturbed state of the atmosphere. Mr. Weld mentions having approached the Falls within half a mile without hearing any sound, while the spray was but just discernible.--Weld, p. 374.] [Footnote 134: "The shores of Lake Erie, though flat, are elevated about 400 feet above those of Lake Ontario. The descent takes place in the short interval between the two lakes traversed by the Niagara Channel. This descent is partly gradual, producing only a succession of rapids. It is at Queenston, about seven miles below the present site of the Falls, that a range of hills marks the descent to the Ontario level. Volney conceives it certain that this must have been the place down which the river originally fell, and that the continued and violent action of its waves must have gradually worn away the rocks beneath them, and in the course of ages carried the Fall back to its present position, from which it continues gradually receding. Mr. Howison confirms the statement, that, in the memory of persons now living in Upper Canada, a considerable change has been observed. The whole course of the river downward to Queenston is through a deep dell, bordered by broken and perpendicular steeps, rudely overhung by trees and shrubs, and the opposite strata of which correspond, affording thus the strongest presumption that it is a channel hewn out by the river itself."--H. Murray's _Historical Description of America_, vol. ii., p. 466.