ral Africa abounds, often requiring to cross
streams that are deep and rapid, and where no bridges exist, these
people are compelled by their very wants to become experts swimmers.
Besides, their hot climate renders the exercise a pleasant one, and many
tribes of them spend half their time in the water.

It was highly improbable that they could not swim--all, or nearly all,
of them. No, this was not the cause of their hesitancy.

And what was?

This question was answered by one of the sailors--though all of us at
the same moment perceived the cause.

"Look yonder!" cried the man, pointing along the water; "look yonder;
yon's what cows 'em--the sharks!"

CHAPTER FIFTY EIGHT.

The stretch of water that lay between the raft and the burning vessel
glittered under the yellow light like a sea of molten gold. On its calm
surface the blazing barque was mirrored, as though another was on fire
below; but the perfect image was broken by occasional rippling, as if
some living creatures were stirring through the water. The very
intensity of the light, dazzling our eyes, prevented us from scanning
the surface with any degree of minuteness. It was like looking against
the sun as the bright orb rises or sets over the sea. The strong light
glancing along the water produced a sheen and a sparkle that
half-blinded us; and, although we had observed an occasional eddy or
rippling motion upon the surface, we had not thought of the cause until
that moment.

Now, however, that our attention was called to this moving of the waters
we had no difficulty in making out the cause. It was the sharks that
were darting about--now rushing impatiently from point to point; now
lying in wait, silent and watchful, like cats, ready to spring upon
their prey. Here and there we could see their huge dorsal fins standing
like gaff-topsails above the surface, now cleaving the water like huge
blades of steel, anon dipping below to appear again at some point nearer
to their expected prey.

From the number of these fins that we observed above water, we came to
the conclusion that there must be hundreds of these voracious creatures
around the blazing barque. In fact there was a perfect "school" of
them, like porpoises or minnows--for the longer we gazed the greater
number of fins and rippling eddies were detected, until at times it
appeared as if the whole surface was thickly covered with these preying
fish!

Their numbers, too, seemed to be c