never-
ceasing roar of deep-toned thunder; and, with a sigh of relief at the
grateful coolness of the sea breeze after the stifling heat of the plain
which they had just crossed, they gladly swung themselves out of the
saddle and, passing their arms through their bridles, proceeded to look
about them.

The beach upon which they found themselves was a very ordinary,
unpicturesque-looking stretch of brown sand running practically
straight, and also practically north and south, as far as the eye could
see in both directions. It averaged about one hundred and twenty yards
in width, was very flat, and on its landward side was bounded by a bank
of red earth ranging from ten to about fifty feet in height, cut into
here and there by "dongas", through one of which they had descended from
the plain to the level of the sand. The ordinary high-water mark seemed
nowhere to reach within less than thirty yards of the toe of the bank,
but there were indications--in the shape of little patches of dry and
crumbling seaweed and other ocean debris--that in stormy weather the
breakers occasionally reached to the foot of the bank and in some places
actually undermined it. At a distance of about half a mile to seaward a
long line of white water betrayed the position of a reef.

"Um!" exclaimed Grosvenor, after he had allowed his gaze to travel over
the prospect for several minutes; "this is a pretty desolate-looking
spot, and no mistake; not at all the sort of place where you would
expect to find precious stones, is it?"

"Why not?" retorted Dick, laughingly. "Gems are sometimes found in the
most unlikely looking places. I did not expect the landscape to be
distinguished by any unusual characteristics; did you?"

"'Pon my word I don't know," replied Grosvenor; "but somehow I expected
it to look very different from this. After all, however, what does the
beauty or otherwise of the landscape matter, so long as the rubies are
really here? And I suppose they are here, somewhere, eh? We haven't
made a mistake and come out at the wrong spot, do you think?"

"Well," admitted Dick, "we may not have hit the precise spot perhaps,
but I think we cannot be more than half a mile from it. Perhaps the
quickest way of finding it will be to search for it. Now, just let me
think for a moment. Those _Flying-Fish_ people started by searching the
beach. The Professor, possessing superior knowledge to the others,
searched the face of the cliff; a