consent.

'Heavens, what an altitude!' said Knight between his pants, and looking
far over the sea. The cascade at the bottom of the slope appeared a mere
span in height from where they were now.

Elfride was looking to the left. The steamboat was in full view again,
and by reason of the vast surface of sea their higher position uncovered
it seemed almost close to the shore.

'Over that edge,' said Knight, 'where nothing but vacancy appears, is a
moving compact mass. The wind strikes the face of the rock, runs up it,
rises like a fountain to a height far above our heads, curls over us
in an arch, and disperses behind us. In fact, an inverted cascade is
there--as perfect as the Niagara Falls--but rising instead of falling,
and air instead of water. Now look here.'

Knight threw a stone over the bank, aiming it as if to go onward over
the cliff. Reaching the verge, it towered into the air like a bird,
turned back, and alighted on the ground behind them. 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. She waited another, and
there was no sign of him.

A few drops of rain fell, then a sudden shower.

She arose, and looked over the bank. On the other side were two or three
yards of level ground--then a short steep preparatory slope--then the
verge of the precipice.

On the slope was Knight, his hat on his head. He was on his hands and
knees, trying to climb back to the level ground. The rain had wetted the
shaly surface of the incline. A slight superficial wetting of the soil
hereabout made it far more slippery to stand on than the same soil
thoroughly drenched. The inner substance was still hard, and was
lubricated by the moistened film.

'I find a difficulty in getting back,' said Knight.

Elfride's heart fell like lead.

'But you can get back?' she wildly inquir