8o NEW YORK STATE MUSEUM 



the ancient falls was situated at the point where the gorge contracts 

 to the width of the narrower channel of the whirlpool rapids. 



It will thus be seen that this interesting problem of the origin 

 of the gorge of the whirlpool rapids, propounded nearly 20 years 

 ago by Dr Pohlman, is by no means wholly solved. We may re- 

 turn to the original solution of the propounder of the question or 

 we may find new evidence which will corroborate Taylor's explana- 

 tion. And who shall say that still other explanations of these fea- 

 tures may not be forthcoming in the future, when those now de- 

 manding attention will be no longer regarded as plausible or suffi- 

 cient? 



The upper gorge and the falls 



plates 1, 2, 4, 5, 11 



Whatever may be believed with reference to the narrow gorge of 

 the whirlpool rapids, most observers agree that the broad and deep 

 gorge from Clifton to the present falls was made by a cataract carry- 

 ing the full supply of water. This, the latest and most readily in- 

 terpreted part of the gorge, has come to an end at the Horseshoe 

 falls of today, and the character of the channel hereafter to be made 

 can only be conjectured. The river has reached another of its 

 critical points, where a rectangular turn is made, and it is not im- 

 probable that, as at the other turns, so here the character of the 

 gorge will change. Already a short channel, considerably narrower 

 than that of the last preceding portion, has been cut by the Horse- 

 shoe falls. (Fig. 19) This narrowness of the channel is due to the 

 concentration of the water at the center of the stream. It is easy to 

 see that Goat island and the other islands owe their existence to this 

 concentration of the water; for at one time, as shown by the shell- 

 bearing gravels, these islands were under water. The channel 

 above the Horseshoe falls has been cut more than 50 feet below the 

 summit of Goat island at the falls, while the upper end of the island 

 is still at the level of the water in the river. 



Goat island lies on one side of the main mass of forward rushing 

 water, which passes it and strikes the Canadian bank, from which it 

 is deflected toward the center of the cataract, which portion is thus 

 deepened and worn back most rapidly. The directions of the cur- 



