In the second section is found the Whirlpool, one of the most interesting and attractive portions of the river. The large basin in which it lies was cut out much more rapidly than any other part of the chasm. And this for the reason that, in addition to the thick stratum of shale, there was, underlying the channel, a large pocket, and probably, also, a broad seam or cleavage, filled with gravel and pebbles. Indeed, there is a broad and very ancient cleavage in the rock-wall on the Canadian side, extending from near the top of the bank to an unknown depth below. Its course can be traced from the north side of the pool some distance in a north-westerly direction. Of course the resistless power of the falling water was not long restrained by these feeble barriers, and here the broadest and deepest notch of any given century was made. The name, Whirlpool, is not quite accurate, since the body of water to which it is applied is rather a large eddy, in which small whirlpools are constantly forming and breaking. The spectator cannot realize the tremendous power exerted by these pools, unless there is some object floating upon the surface by which it may be demonstrated. Logs from broken rafts are frequently carried over the Falls, and, when they reach this eddy, tree-trunks from two to three feet in diameter and fifty feet long, after a few preliminary and stately gyrations, are drawn down end-wise, submerged for awhile and then ejected with great force, to resume again their devious way in the resistless current. And they will often be kept in this monotonous round from four to six weeks before escaping to the rapids below.