This outlet is about 1170 yards from the western end of the chasm, and some 600 from its eastern end; the whirlpool is at its commencement.

The Zambesi, now apparently not more than twenty or thirty yards wide, rushes and surges south, through the narrow escape-channel for 130 yards; then enters a second chasm somewhat deeper, and nearly parallel with the first.
Abandoning the bottom of the eastern half of this second chasm to the growth of large trees, it turns sharply off to the west, and forms a promontory, with the escape-channel at its point, of 1170 yards long, and 416 yards broad at the base.

After reaching this base, the river runs abruptly round the head of another promontory, and flows away to the east, in a third chasm; then glides round a third promontory, much narrower than the rest, and away back to the west, in a fourth chasm; and we could see in the distance that it appeared to round still another promontory, and bend once more in another chasm towards the east.

In this gigantic, zigzag, yet narrow trough, the rocks are all so sharply cut and angular, that the idea at once arises that the hard basaltic trap must have been riven into its present shape by a force acting from beneath, and that this probably took place when the ancient inland seas were let off by similar fissures nearer the ocean.
The land beyond, or on the south of the Falls, retains, as already remarked, the same level as before the rent was made.

It is as if the trough below Niagara were bent right and left, several times before it reached the railway bridge.