as illustrating the Geology of North America. 13 



by the following section, in which the difference of level in 

 the two lakes is exhibited, although, of course, on a scale of 

 height altogether disproportioned to the extent of country over 

 which the declivity is spread. This fall of 1 foot in 160 

 would not be thought remarkable in any inland stream of 

 common size ; but in the case of such a vast body of water as 

 the Niagara contains, (which forms a large proportion of the 

 whole fresh water of the earth, and has been calculated at one 

 hundred millions of tons per hour,) the action, when once set 

 in motion, must be enormous; nor can we feel surprise at the 

 powerful effects which it produces, and on which I am now 

 about to remark. 



< — \>Ehft^--Trfo>/y>'y^r-e'^^ v 



3 6 12 24 36 miles. 



A. Lake Erie. 



B. The rapids above the cataract, having a fall of about 55 feet. 



C. The falls of Niagara 160 



From C to Queenston, D, is about 7 miles of violent rapid, 



gradually subsiding, and having a fall altogether of 115 



Total "330 feet. 



The very trifling fall in the navigable parts of these 36 miles is not here 

 taken into account, but may be 2 or 3 feet of the above number. They 

 extend from A to B, and from D to E, or Lake Ontario. 



But first, in order more clearly to illustrate the nature of 

 the country and the situation of the cataract, I shall quote a 

 short passage from Captain Hall's interesting account of it, 

 which is in itself perfectly clear, and has been corroborated 

 to myself by the oral testimony of my friend Sir Howard 

 Douglas, whose intimate acquaintance with the locality, and 

 whose acute discrimination on all such subjects, no one will 

 dispute. 



" In the first part of the course of the Niagara, this river 

 slips quietly along out of Lake Erie nearly at the level of the 

 surrounding flat country; so nearly so, indeed, that if by any 

 of those causes which swell other rivers, but have no effect 

 here, the Niagara were to rise 8 or 10 feet perpendicularly, 

 the adjacent portion of Upper Canada on the west, and of the 

 State of New York on the east, would be completely laid 

 under water. After the river passes over the falls, however, 

 its character is immediately and completely changed. It then 

 runs furiously along the bottom of a deep wall-sided valley, 

 or huge trench, which seems to have been cut into the horizontal 

 strata of the limestone rock, by the continued action of the 

 stream during the lapse of ages. The cliffs on each side are, 



