188 FRAGMENTS OF SCIENCE 



great and prodigious cadence of water, to which the uni- 

 verse does not offer a parallel." The height of the fall, 

 according to Hennepin, was more than 600 feet. "The 

 waters," he says, "which fall from this great precipice do 

 foam and boil in the most astonishing manner, making a 

 noise more terrible than that of thunder. When the wind 

 blows to the south its frightful roaring may be heard for 

 more than fifteen leagues." The Baron la Hontan, who 

 visited Niagara in 1687, makes the height 800 feet. In 

 1721 Charlevois, in a letter to Madame de Maintenon, after 

 referring to the exaggerations of his predecessors, thus 

 states the result of his own observations: "For my part, 

 after examining it on all sides, I am inclined to think that 

 we cannot allow it less than 140 or 150 feet" a remark- 

 ably close estimate. At that time, viz., a hundred and 

 fifty years ago, it had the shape of a horseshoe, and rea- 

 sons will subsequently be given for holding that this has 

 been always the form of the cataract, from its origin to 

 its present site. 



As regards the noise of the fall, Charlevois declares 

 the accounts of his predecessors, which, I may say, are re- 

 peated to the present hour, to be altogether extravagant. 

 He is perfectly right. The thunders of Niagara are for- 

 midable enough to those who really seek them at the base 

 of the Horseshoe Fall; but on the banks of the river, and 

 particularly above the fall, its silence, rather than its noise, 

 is surprising. This arises, in part, from the lack of reso- 

 nance; the surrounding country being flat, and therefore 

 furnishing no echoing surfaces to reinforce the shock of 

 the water. The resonance from the surrounding rocks 

 causes the Swiss Eeuss at the Devil's Bridge, when full, 

 to thunder more loudly than the Niagara. 



