Science, Geology and Physics 



notwithstanding which, the goal of certain knowledge about the 

 age of Niagara has not yet been reached. 



Very naturally, geological knowledge concerning Niagara has 

 not developed in geological order. Recent and more obvious 

 evidence has attracted first attention, while the remote and funda- 

 mental problems have received later consideration. Inquiries pro- 

 ceeding from effect to cause have led backward to antecedents 

 and formative events, with the result that while many correct 

 observations and valuable discoveries of existing facts have been 

 made from time to time, — as, for instance, the drift-filled channel 

 of St. David's or the submerged valleys of Lake Ontario — the 

 original theories of the causes of these conditions have been upset 

 by the later discoveries of other investigators. Thus it has been 

 that pioneers who have been correct in their observations have 

 been incorrect in their theories, and followers who possibly have 

 had correct theories have benefited by the observations of their 

 predecessors. 



Many of the early observers of the physical phenomena of 

 Niagara gave much attention to the formation of mists, rainbows, 

 sound, the color of the water, the upward jets beneath the Falls, 

 etc. Triangulation and surveys of the crest have proceeded with 

 increasing accuracy since about 1838. The height of the Falls, 

 stated by Father Hennepin in his amazement to be 600 feet, 

 was ascertained with approximate accuracy as early as 1805 

 to be 1 58 feet, and in recent years has been fixed by the United 

 States Geological Survey at 160 feet for the Horseshoe Fall. 

 The volume of the river was a subject of speculation in 1805, 

 when it was estimated at 3,000,000 tons. Another estimate at 

 the same period was 400,000 tons as the weight of the mass 

 between the crest and bottom of the Falls. In 1 882, it was esti- 

 mated that from 85,000,000 to 1 02,000,000 tons of water passed 

 in an hour. But this branch of the subject merges into the 

 hydraulic and industrial use of the Falls, which is discussed else- 

 where in this work. 



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