As we turned a sharp corner they began to wave signals and shout warnings to us to look out for the explosions.

It was all very well to warn us, but what could WE do?
You can't back a raft upstream, you can't hurry it downstream, you can't scatter out to one side when you haven't any room to speak of, you won't take to the perpendicular cliffs on the other shore when they appear to be blasting there, too.

Your resources are limited, you see.

There is simply nothing for it but to watch and pray.
For some hours we had been making three and a half or four miles an hour and we were still making that.

We had been dancing right along until those men began to shout; then for the next ten minutes it seemed to me that I had never seen a raft go so slowly.