Whirlpool and Rapids below the Falls of Niagara. 35 
is now seen on the sides of the declivity near Brock’s monument. 
The smooth, scooped out appearance in the solid limestone rock, 
as before alluded to, indicates that long before the waters were 
concentrated at the ravine at Queenston, they were for ages 
sweeping over the precipice on each side of the present opening. 
When the falls had retrograded as far as is represented by the 
dotted lines in fig. 4, their further progress was arrested by phys- 
ical changes constantly but slowly going on, according to Mr. 
Lyell, which have so materially changed the surface and condition 
Fig. 4. i 
The supposed situation of the Falls when near what is now called the Whirlpool. 
LAKE OR SEA 
The dotted lines mark the deep lateral valley filled with drift, for a considerable distance 
t Lake. 
owards the La 
