On the Falh of Niagara. 329 



discover that the gorge through which the Niagara river flows, ap- 

 proaches much nearer to the form of a parallelogram than to the ir- 

 regular triangular figure which he supposes. His desire to reduce 

 the solid dimensions of this valley, has led him to represent it with 

 an outline very different from that which ])elongs to it, and his cor- 

 rection is almost as wide of nature as his first imaginary section. 



But suppose for a moment that the cataract has been at Queens- 

 town heights and of a minor elevation, it l)y no means follows that 

 the erosion of its bod would on that account be effected more rap- 

 idly. 



The action of tlie torrent is not expended in wearing away the 

 whole surface of the wall of rock, but in undermining it, by the 

 enormous momentum of the ever falling mass of waters which are 

 continually wearing and removing the loose materials at its base. 

 It is reasonable to infer that a certain height of fall is necessary to 

 this result. 



Having thus shown the inadequacy of the data upon which the 

 computations of the age of this cataract have been made to rest, I 

 shall proceed to develope some features of the neighboring district 

 which render it very doubtful, whether the Falls of Niagara ever 

 have been at QueenstowTi. 



It is a very generally received opinion and may so far as present 

 evidence extends, be taken for granted, that the country adjacent to 

 Niagara and the lakes was originally covered with a vast lake, or 

 rather inland sea, which some change in the configuration of the re- 

 gion contracted to the still very extensive masses of fresh water now 

 remaining. The passage of such a body of water over the surface 

 would deeply indent all the exposed portions of the land. Rushing 

 in its descent from lake Erie to lake Ontario, from a higher to a low- 

 er plain, and across a slope like that at Queenstown, it would inevit- 

 ably leave a deep and long ravine. But further, the whole of this 

 region has been grooved and scarified by the same far sweeping cur- 

 rents which denuded the entire surface of North America, and 

 strewed its plains and mountains with boulders, gravel, and soil from 

 the north. Such a diluvial valley, of greater or less length and 

 depth was, 1 cannot help believing, probably the commencement of 

 the present remarkable trough below the Falls.* 



* Mr. Fairholme in ascribing to the Niagara the duration which he has, obvi- 

 ously regards it as wholly posi-diluvial ; he is therefore constrained to grant the 

 pre-existence of the denuding actions for which I contend. 



Vol. XXVn.— No. 2, 12 



