He struggled bravely, and I thought that we should have saved him, when suddenly I perceived an expression of despair come upon his face, and there before our eyes he was sucked down into the cruel swirling blue depths, and vanished.

At the same moment I felt our canoe seized as with a mighty hand, and propelled with resistless force towards the rock.
We realized our danger now and rowed, or rather paddled, furiously in our attempt to get out of the vortex.

In vain; in another second we were flying straight for the arch like an arrow, and I thought that we were lost.

Luckily I retained sufficient presence of mind to shout out, instantly setting the example by throwing myself into the bottom of the canoe, 'Down on your faces -- down!' and the others had the sense to take the hint.

In another instant there was a grinding noise, and the boat was pushed down till the water began to trickle over the sides, and I thought that we were gone.