GEOLOGY OF THE WESTERN DISTRICTS OF CANADA. 503 
actually taken place; and the appearance of the bank below the Falls 
where these changes had occurred within the memory of man is so 
precisely identical in character with the whole gorge for seven miles 
below, that a philosophical observer of the phenomena of nature 
would be irresistibly impelled to the conclusion that the great Fall 
formerly existed at Queenston, and that the river must have sawed 
its way through this whole distance—provided sufficient time were 
allowed for the completion of the work. Sir Charles Lyell concludes, 
after the most careful and repeated investigation of the recorded 
facts, as well as the varying nature of the strata, that the average 
recession was not more than one foot per year, and that consequently 
it must have taken 35,000 years for the retreat of the Falls from the 
escarpment at Queenston to the present site. It seems by no means 
improbable that such result would be no exaggeration of the truth, 
although we cannot assume that the retrograde movement has been 
uniform. At some points, owing to the greater softness of the strata 
and the lesser width of the ravine, it might be expected that quicker 
progress might be made; but on the other hand, it must be observed 
that at the commencement of the process the Fall must have been 
nearly twice its present height and consequently the amount of 
material to be excavated proportionally greater. This estimate of the 
time required for the scooping out of the gorge, as Hugh Miller 
remarks, is based upon exactly the same process of reasoning by 
which one would infer that a labourer who had cut a ditch two 
hundred yards long at the rate of ten yards per day and was still at 
work without intermission, had begun to cut it just twenty days 
previous. 
This theory based upon historical, is amply corroborated by 
geological evidence. If we examine the structure of Goat Island, 
between the American and Horse Shoe Fall, we shall find that the 
superficial deposit consists of regularly stratified horizontal fresh 
water beds of gravel, sand and loam, in all about twenty feet thick, 
copiously charged with shells of the same species as now inhabit the 
waters of Lake Ontario and the Niagara river. These beds are 
entirely above the level of the water as it precipitates itself into the 
mighty gulf. Precisely the same formation will be found on the 
American side of the river exactly opposite, and extending for a 
considerable distance below the Falls on the top of the cliffs, and 
bounded towards the east by a distinctly traceable ancient river 
