“The general form of the falls is slowly changing from age to age. When Father Hennepin saw them, a century and three-quarters ago, they presented little of that curved and indented outline which now forms their most striking peculiarity. The fall on the western side extended in nearly a straight line from the head of Goat island to Table Rock, which terminated in a bluff that turned a portion of the water from its direct course, forming another cataract which fell to the east. A century later, this projecting rock had disappeared, but the spot which it had occupied was distinctly traceable. From the character of the strata through which the water has slowly worn its way back from the shores of Lake Ontario, we learn what must have been the appearances of the fall at any period of its history. Thus it can never have overcome the descent of three hundred and fifty feet at Lewiston at a single leap, but must have formed at least three cataracts separated by intervening rapids. When the falls occupied the position of the whirlpool, three miles below their present site, the descent was evidently greater than at any period before or since. But there never can have been a period when their beauty equaled that which they present at the present age. The immense breadth of the sheet of falling water, its graceful sweep of curves, and the picturesque islands that stud the brink, belong solely to our present Niagara. The falls recede at present, we are told, at the rate of something less than a foot in a year. Geology is able to predict that when a recession of a mile has taken place, some five or six thousand years hence, the hight of the fall will be reduced by a score of feet. Another five thousand years will subtract two score more of feet. Ten thousand years more, when the fall shall have worn its way four miles further back, all that constitutes Niagara will have disappeared, and the whole descent will be accomplished by a series of rapids like those near the whirlpool.