The long, round object the fellow was pushing in front of him had diminished by half since he had left the island shore.
Plainly, then, he was leaving part of the object behind him; and it was equally plain that it was this object which gave him a secure foothold on the treacherous and shifting sands.
The scout strained his eyes upon the diminishing roll in front of the figure.
He made out long, thin slabs of wood, bound closely together by ropes.
Ah! The scout had pierced the mystery.
The thin slabs, bound together by ropes, when unrolled formed a sort of movable causeway, the length of each slab being sufficient to resist the soft sands and offer footing and support.
By that time the man was quite near, and his bundle of slabs had been almost exhausted.
The scout had made up his mind as to what he should do.
Crouching down behind the kegs, he waited, every nerve tense as a forestay, and every muscle primed for quick action.