The gale at that time, however, was blowing in a direction which would appear to ensure safety to them; into, and not out of, the poisonous marshes.

Did they, then, foresee that it would change?
Did they expect it to veer like a cyclone and presently blow east with the same vigour as it then blew west?
That would carry the vapour from the inky waters out over the sweet Lake, and might even cause the foul water itself to temporarily encroach on the sweet.

The more he thought of it, the more he felt convinced that this was the explanation; and, as a fact, the wind, after dropping, did arise again and blow from the east, though, as it happened, not with nearly the same strength.

It fell, too, before long, fortunately for him.
Clearly the birds had anticipated a cyclone, and that the wind turning would carry the gases out upon them to their destruction.

They had therefore hurried away, and the fishes had done the same.
The velocity of the gale which had carried him into the black waters had proved his safety, by driving before it the thicker and most poisonous portion of the vapour, compressing it towards the east, so that he had entered the dreaded precincts under favourable conditions.