NIAGARA. 203 



The annexed highly instructive map has been re- 

 duced from one published in Mr. Hall's ' Geology of 

 New York.' It is based on surveys executed in 1842, 

 by Messrs. Gibson and Evershed. The ragged edge of 

 the American Fall north of Goat Island marks the 

 amount of erosion which it has been able to accom- 

 plish, while the Horseshoe Fall was cutting its way 

 southward across the end of Goat Island to its present 

 position. The American Fall is 168 feet high, a preci- 

 pice cut down, not by itself, but by the Horseshoe Fall. 

 The latter in 1842 was 159 feet high, and, as shown by 

 the map, is already turning eastward, to excavate its 

 gorge along the centre of the upper river. P is the 

 apex of the Horseshoe, and T marks the site of the 

 Terrapin Tower, with the promontory adjacent, round 

 which I was conducted by Conroy. Probably since 

 1842 the Horseshoe has worked back beyond the posi- 

 tion here assigned to it. 



In conclusion, we may say a word regarding the 

 proximate future of Niagara. At the rate of excava- 

 tion assigned to it by Sir Charles Lyell, namely, a foot 

 a year, five thousand years or so will carry the Horse- 

 shoe Fall far higher than Goat Island. As the gorge 

 recedes it will drain, as it has hitherto done, the banks 

 right and left of it, thus leaving a nearly level terrace 

 between Goat Island and the edge of the gorge. Higher 

 up it will totally drain the American branch of the 

 river; the channel of which in due time will become 

 cultivable land. The American Fall will then be trans- 

 formed into a dry precipice, forming a simple continua- 

 tion of the cliffy boundary of the Niagara gorge. At 

 the place occupied by the fall at this moment we shall 

 have the gorge enclosing a right angle, a second whirl- 

 pool being the consequence. To those who visit Niag- 

 ara a few millenniums hence I leave the verification of 



