36 Whirlpool and Rapids below the Falls of Niagara. 



the precipice at Queenston, and there commence anew its great 

 work of retrocession. It will be seen by reference to fig. 4, that 

 the ravine at dueenston and onward, to the whirlpool, is not par- 

 allel to the lateral valley, (represented by dotted lines,) but makes , 

 an angle, the apex of which is the head of the valley. When 

 the falls advance to the dotted lines, W, which mark the boun- 

 dary of this valley of drift, and had broken and cut its way 

 through the hard limestones, &c, into this soft and very thick 

 bed, a violent and rapid excavation would go on by the mighty 

 force exerted from the falling cataract on the soft material, most 

 of which would be carried away in the form of mud. As this 

 drift descended far into the soft shale below the quarztose rock, 

 it is highly probable that it was cleared out, forming a vast cir- 

 cular pit, and it is this which caused the gyratory motion of the 

 water. Fig. 2, W, gives a representation of this pit. Had the 

 falls retrograded a few yards east of the point, W, which repre- 

 sents the head of the valley, there would not have been what is 

 now called the whirlpool ; for then it would not have entered the 

 soft bed of drift at the head of the valley, out of which I believe 

 the whirlpool was formed. 



On the falls retreating from the whirlpool, it will be noticed, 

 that the hard quartzose rock, 2$ fig. 2, would form the base of 

 the falls, and then an obstruction would be made to the free 

 egress of the water ; the hard rocks would then fall on this pave- 

 ment, which would greatly increase the obstruction and give rise 

 to the rapids, and this would continue as the falls receded, until 

 by the indication of the strata, this hard rock would by degrees 

 sink so low as to allow a depth sufficient for the waters to flow 

 without commotion. This will be evident by an inspection of 

 fig. 2, the stratum, 3, being soft shale. The inclination of the 

 strata and the soft character of the rocks through which the river 

 flows at the falls, are the causes of that apparently miraculous 

 tranquillity which is observed to take place immediately after the 

 river has plunged down the precipice. This sudden repose sur- 

 prised me more than the falls themselves. 



