d was, for some considerable
distance in the direction followed by Dick, quartzite; but at a point
about a mile from the spot where he had parted from Earle it changed to
a black, bituminous limestone, studded here and there with ammonites.
Dick, who knew little or nothing about geology, merely noticed the
change in the character of the rock, and sauntered on, eagerly scanning
its face, in the hope of finding a spot where it might be scalable by
men carrying moderately heavy burdens. And at length he reached, as he
believed, such a spot, where the black rock seemed to have been riven by
some mighty natural convulsion, the rift forming a steep and exceedingly
narrow gully leading to the summit. Naturally, he at once started to
climb this gully, with the object of testing its practicability; and he
had traversed nearly two-thirds of its length when, as he scrambled up,
his attention was suddenly attracted to a sort of pocket in the rock,
which had been laid open by a fall. What particularly attracted his
attention toward this pocket was the fact that it contained a
considerable number of bright green crystals, which struck him as being
peculiar not only from their rich colour, but also from the fact that
they were all of practically the same shape, namely hexagonal. So
greatly did he admire them that he put a couple of the largest in one of
his pockets, intending to show them to Earle and ask him whether
perchance they were of any value. Then he pushed on again and soon
reached the upper end of the gully, when he found himself, somewhat to
his amazement, on a vast tableland, stretching as far as could be seen,
with what looked like a big forest at a distance of some ten miles.

Having completed his survey, Dick descended the gully and returned to
the camp, to find that Earle was still absent; he therefore set out to
seek him and report his success. Some two miles beyond the camp he met
the American returning, considerably disgusted, he having failed in his
search, and at once Dick reported his triumph, incidentally producing
the crystals and asking if Earle happened to know what they were.

"Know what they are?" echoed Earle, after most carefully and
interestedly examining the stones. "Why, of course I do. Don't you?"

"Haven't the least idea," answered Dick. "But they struck me as being
rather pretty, and I thought I would take them back to my sister as
souvenirs of my travels. There are dozens more where thes