NIAGARA AS A TIMEPIECE. 5 



many phases in the history of the lakes in their bearing upon the 

 growth of the falls, and only after that field work could any at- 

 tempts at computing the age of the falls be made. A few of the 

 necessary discoveries may be referred to : (a) The Niagara River 

 did not drain the Erie basin in ancient times, and consequently 

 there was no ancient river channel ready for the modern stream. 

 (6) All the features of the chasm are modern, and only very slight- 

 ly modified by the older forms of land sculpturing, (c) After the 

 birth of the river, Huron and the sister lakes did not empty into 

 the Niagara drainage until comparatively recent times, and there- 

 fore, on account of draining only the Erie basin, the volume of the 

 water cascading over the early falls was small. (fZ) Then the de- 

 scent of the river varied greatly, being for very long ages less 

 than now, and again temporarily much greater. (The observa- 

 tion of the greater height of the falls was made by Prof. G. K. 

 Gilbert, who has followed the writer in the other important 

 points named.) (e) The determination of the amount of work 

 accomplished by the falls during each of the episodes of the river 

 seemed the most difficult, but this has been accomplished with 

 partial success. These things have been mentioned to show that 

 the computation of the approximate age of the falls has been a 

 complex question and also one of tedious delays, yet a problem 

 that will continue to awaken interest so long as men endeavor 

 to ascertain the antiquity of the ice age and the correlated an- 

 tiquity of man. Niagara River is perhaps our best chronometer, 

 and by applying the age of the falls to the deserted shore lines 

 the antiquity of possibly man-inhabited river banks of distant 

 regions and forgotten times will be discovered. Directly the 

 determination of the age of the falls is a stepping stone to the 

 date of the close of the ice age. Under these circumstances the 

 investigations seem to justify the presentation of the results to 

 the general reader, leaving to the essayist the repetitions of the 

 other geographical or picturesque features or the pretty stories 

 of Niagara. Even the great Lyell had no better means of ascer- 

 taining the antiquity of the falls than mere conjecture, for a long 

 period of observation was necessary. Strangely, however, his 

 suggestion was not far from the computations based upon our 

 increased knowledge. This coincidence arose from the occurrence 

 of compensating errors, those corrected on the side of reduction 

 of time used alone giving results further from the truth than the 

 mere conjecture, as the varying conditions of the river which 

 increase its antiquity were not known. 



Some Modern and Ancient Features of the Niagara 

 District. — The map of the Niagara district (Fig. 5) shows a 

 table-land a few feet above the surface of Lake Erie, and extend- 

 ing northward for nineteen miles to the edge of the Niagara 



