Volume of the Niagara River. 23 



of Niagara River, are now submitted, with the hope that they 

 may furnish facts in this branch of the science of hydrography 

 which will be used as data by scientific men for various cal- 

 culations ; and with the hope, also, that others may be in- 

 duced to commence a system of similar admeasurements of 

 the other great rivers of the earth, such as the Mississippi, 

 Ganges, &c., which may form a basis of comparison of their 

 relative magnitudes. 



I have also subjoined some calculations, from which it will 

 appear that the motive-power of the cataract of Niagara ex- 

 ceeds, by nearly forty fold, all the mechanical force of water 

 and steam power rendered available, in Great Britain, for the 

 purpose of imparting motion to the machinery that suffices 

 to perform the manufacturing labours for a large portion of 

 the inhabitants of the world, including also the power applied 

 for transporting these products by steam-boats and steam-cars, 

 and their steam-ships of war, to the remotest seas. Indeed it 

 appears probable, that the law of gravity, as established by the 

 Creator, puts forth in this single waterfall more intense and 

 effective energy, than is necessary to move all the artificial 

 machinery of the habitable globe. 



In order that confidence may be placed in the estimates 

 now presented, it may be proper to subjoin a statement of 

 the modes in which the admeasurements were made, and the 

 calculations based upon them were accomplished. 



After having personally, and with much labour, rounded 

 the fearfully rapid current of the Niagara river above the Falls, 

 at Black Rock, where the bottom or bed appears to be nearly 

 level from one side to the other, and the depth about thirty- 

 two feet ; and having repeated a course of similar admeasure- 

 ments below the falls at Queenston, where the current is 

 more placid, and the depth in the deepest place about one 

 hundred and sixty feet ; and after having lost an anchor in 

 the course of these experiments, I finally found it necessary 

 to have recourse to the aid of an engineer, in order to perfect 

 all the admeasurements, which my limited time would not al- 

 low me to complete. For this purpose the services of Mr E. 

 R. Blackwell, of Black Rock, a most skilful and accurate 

 engineer, were engaged by me. His residence at that time 



