68 Mr. Allen on the Volume of the Niagara River. 



ments for ascertaining the quantity of water precipitated by the 

 grand cataract, and drained from the vast area of country border- 

 ing on the great lakes of North America. This subject has long 

 remained a matter of mere conjecture, although unusual facilities 

 are offered for making the admeasurement of the volume of this 

 majestic river, from the circumstance of its issuing from Lake 

 Erie in an average equalized current throughout the various sea- 

 sons of the year, unaffected by the droughts of summer and the 

 floods of winter. In order to ascertain the average volume of 

 water discharged by most other rivers of the earth, it becomes 

 necessary to multiply a great number of observations during the 

 several seasons of the year. But the flow of the Niagara River 

 remains always nearly the same, varying only from the action of 

 the winds on the surface of Lake Erie, and from a periodical suc- 

 cession of several rainy or dry years in the broad regions of the 

 upper lakes.* 



The results of the admeasurements of the volume of water 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 calculations ; 



* It appears from the best information I was enabled to obtain, that a strong 

 breeze or gale on Lake Erie, in the direction of the outlet of this lake, will cause 

 the waters to become heaped up at that end, so as to produce a rise of the level 

 of about two feet ; and a corresponding rise of the Niagara River. A subsidence of 

 the level of the surface to an equal extent occurs, whenever a gale takes place in 

 an opposite direction, making a total variation of about four feet in the rise and fall 

 of the level of the river, from the simple action of the wind on the surface of the 

 lake. These changes of level have sometimes taken place in the course of a few 

 hours. A nearly equal, but more gradual change of level, is produced, as before 

 stated, by the alternations of a period of several rainy years followed by a period 

 of successive years of comparative drought. 



The descent of the waters of Niagara River, from the outlet of Lake Erie, is at 

 first so considerable, as to cause the flow of the current to become accelerated to a 

 velocity of about eight miles per hour. By means of an embankment constructed 

 parallel with the shore along the margin of the river, the level of the surface of 

 Lake Erie is maintained, or upheld, throughout a distance of several miles, above 

 the level of the descending stream. This embankment serves to form a portion of 

 the Erie Canal, and also to convey a supply of water to several large flour-mills at 

 Black Rock, thus affording an efficient fall of about five feet. 



From the general levelness of the low banks of the river between Black Rock 

 and Levviston, it appears probable that water power to any extent that ever will be 

 required, may be obtained by diverting the water of the Niagara River over the table 

 land adjacent to its bed; and that mills might there be erected sufficient to grind 

 all the wheat produced on the broad regions of country, whose tributary waters 

 swell the great lakes and the Niagara, affording unrivalled facilities for transporting 

 the wheat to these mills. 



