t the
wonderful way in which the earthquake had split and piled up the rocks
into the form of a natural impregnable fortress, including both the
cavern and the basin. There was one point, and one only, at which this
natural fortress could be entered, and upon his previous visit he had
passed through it twice without noting this fact; now, however, he not
only took notice of it, but saw also that a small rampart, composed of a
dozen or so of stones, that could be arranged in five minutes, would
enable a single man to hold the place against an army, or, at all
events, so long as his ammunition held out. So strongly did this idea
impress itself upon him that he could not resist the temptation to
actually construct this small rampart then and there.

"Stop a moment, you two," he cried; "I have a fancy for trying a little
experiment. Just bring me along a few of the heaviest pieces of rock
that you can conveniently handle."

And, seizing a block himself, he carried it to a certain point, and
threw it on the ground. Then on and about this he piled the others that
were brought to him until, within ten minutes, he had constructed a
breastwork of dimensions sufficient to efficiently screen one man from
the fire of an enemy, while it enabled him, through a small loophole, to
effectually enfilade the one only spot at which that enemy could
possibly enter. He flung himself down behind the barricade and peeped
through the loophole. The defence was now complete.

"There," he exclaimed, in tones of perfect satisfaction, "if anybody
should ever come here in the future, and require a citadel upon which to
retreat against overwhelming odds, this is the place. And so long as he
can command the nerve to remain behind this barricade and maintain a
steady rifle-fire upon that narrow gap--through which, as you may see,
only one man can pass at a time--he will be absolutely safe. Well,
thank God, _we_ are not likely to need its protection, for we ought to
be at sea on the third evening from now."

The following day was devoted by the three men to the task of putting
the remainder of the gold bricks on board the cutter; and this they
succeeded in accomplishing before knocking-off work for the day; but it
meant that they had to work hard and late to do it. Meanwhile Flora was
equally busily engaged upon the work of getting together, from the
heterogeneous assortment of clothing that had formed part of the
_Mermaid's_ cargo, a suffic