NIAGARA FALLS, 
401 
But this event, though a certain result of existing causes, must still be inconceivably dis¬ 
tant ; and Niagara, for thousands of years, will continue to be the Thunder of Waters, whose 
magnificence no pen can describe, no pencil can express ; which to be appreciated must be 
seen in its vast tumultuous waves, as they sweep down the rapids and are hurled into the 
immense chasm below, and heard in its voice of thunder, which drowns all other voices, and 
reverberates in one perpetual roar of sound and echo. 
Note. —The quantity of water flowing down the Niagara river has been variously estimated by different observers. 
Mr. Dwight estimates the amount at. 301,392,742 cubic feet per minute. 
Mr. Darby,. 27,878,400 “ “ 
Mr. Pickens,...;. 3,087,533 “ “ 
Mr. Barrett,. 19,500,000 " “ 
The last estimate is from three different observations made at Black Rock during the high water of 1838 and 1839. 
The extremes of all the observations did not vary more than 20,000 feet per minute. 
Mr. Barrett informs me that the quantity of water taken out by the different canals is as follows : 
Erie canal, 30,000 cubic feet per minute. 
Welland canal,* 7000 cubic feet per minute. 
Illinois canal, from 5000 to 10,000 cubic feet per minute. 
In addition to this estimate, there is a considerable waste of water along these canals, which is not taken into the account. 
All these amounts are small when compared with the great body of water flowing into this channel, and we can scarcely 
suppose that this abstraction will produce any appreciable difference in the rate of recession; but there are other causes 
which will certainly produce an important diminution. 
* This amount will be greatly increased by the enlargement of this canal. 
[Geol. 4th Dist.] 
51 
