Questions naturally arise in calculating the age of Niagara. If, as all the facts seem to indicate, this river has had a very recent beginning, what then did it do before it occupied its present course? What will be its final destiny? What will happen when it has worn its Gorge back to Lake Erie? Or will the general level of the land be so changed that the Falls will never recede to the lake? The last and most important of all is: How long has it taken the Falls to grind out the Gorge thus far? This latter question, viewed in its relation to the first one, forms the basis of the present chapter. The great work of the Cataract is going on before our very eyes. The history of this great river is working itself out at the height of its glory, in an age when all can behold. It is the more interesting since it is the only example of the kind known. One can easily look back to the time when the water flowed along the top of the plateau to Lewiston and the Falls were situated at that point. This date, of course, witnessed the birth of Niagara, for, wherever the waters flowed before, they could not have taken this course before the Falls began their work. The day that witnessed the beginning of the one witnessed also the birth of the other. Likewise one can not help looking forward to the day when Niagara shall have accomplished its work, when its waters shall have completely ground the plateau in two, and so drained Lake Erie to its bottom.
[Illustration: The American Fall, July, 1765.
From an unsigned original drawing in the British Museum.]
What did the waters of the lakes do before the Niagara began its history? How long has it been at its present work? These are the questions interesting to every one; and by far more interesting to one who is making a study of the formative forces now contributing, and which have contributed to bring about the present characteristics of surface structure. A few important facts exist, and these now are beyond doubt, upon which rest the inferences concerning the age of the Falls. In ancient times the waters of Lake Erie did not find an outlet through Niagara River, so there was no channel ready made for the river when it began its present course. Even after the beginning of the river the upper lakes, Huron, Michigan, and Superior, did not discharge their waters through Niagara. Until comparatively recent times only the waters from Lake Erie discharged through this channel and therefore for many ages only a small fraction of the present volume could possibly have been at work on the Falls.