They themselves were in a dead calm.
'A boat crosses Niagara immediately at the foot of the falls, where the water is quite still, the fallen mass curving under it.

We are in precisely the same position with regard to our atmospheric cataract here.

If you run back from the cliff fifty yards, you will be in a brisk wind.

Now I daresay over the bank is a little backward current.' Knight rose and leant over the bank.

No sooner was his head above it than his hat appeared to be sucked from his head--slipping over his forehead in a seaward direction.
'That's the backward eddy, as I told you,' he cried, and vanished over the little bank after his hat.
Elfride waited one minute; he did not return.