Niagara Falls 



ings which show that its waters were discharged across the divide 

 by a channel into the present Wabash River and thence into 

 the Ohio. This channel can be traced throughout most of its 

 course very easily. There are at least four distinct shore lines 

 preserved to us, which show four successive levels of the lake 

 as it reached lower outlets before the Niagara River was born. 

 All of these old shore lines can be traced throughout most of 

 their courses. 



As the ice continued to retreat, next we notice the greatest 

 change in the elevation of the surface of the water. The ice 

 front finally passed to the north of the present Mohawk River, 

 thus allowing the waters to escape by that outlet, and, as a con- 

 sequence, lowering the surface of the lakes by over five hundred 

 feet. This drained a great extent of land and dropped the 

 surface of Ontario far below the present level of the Niagara 

 escarpment. Then for the first time the Niagara began to flow, 

 and its Falls began their work. Immediately upon the formation 

 of this new, lower lake it began the work of leaving its history 

 carved upon the rocks, sands, and gravels which formed its 

 shores. Its first ancient beach is more easily traced for almost 

 its entire course than any of the other old levels. It does not 

 even take the trained eye of the scientist to see its unmistakable 

 history written in the sands. The earliest western travellers 

 describe the Ridge Road running along this old, deserted beach 

 as showing unmistakable signs of having been an ancient shore 

 line of the lake. 



In following the course of this old shore line a gradual slope 

 is noticed, and if this was a shore line, we must account for this 

 variation in elevation, since the surface of the water is always 

 level. The explanation is to be found in the fact that portions 

 of the earth's surface are gradually rising while others are as 

 gradually sinking. On comparing the old coast line with the 

 level of the present one, we find that the lake has gradually 

 inclined to the south and the west. This change in elevation had 

 its share in determining the configuration of the lake as well as 



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