ath his feet, with a strange
quivering, as if some vast force were passing, and a dull muttering, as
of subterranean thunder, made the tree quiver in his grasp.

A few seconds later, as he waited for a repetition of the earth-tremor,
knowing now full well that he had for the first time experienced a
couple of earthquake shocks, there came from away in front a deep heavy
boom, following a strange rushing sound, evidently from the summit of
the volcano--the huge safety-valve from which the pent-up forces of the
earth escaped to the open air.

Oliver struggled forward a few yards into a clearer spot, where he could
just catch a glimpse of the crater of the mountain, and, as he had
expected, there was the great globe-like cloud riven into rags of
vapour, while dark-looking bodies were falling in various directions
about the summit.

As he gazed, the rain of falling fragments ceased, and the torn-up
flecks of cloud seemed to be drawn slowly together again by the currents
of air on high, first one and then another coalescing, as the tiny
globules of spilt mercury glide one into another, till all are taken up.
And it was so here, the mysterious attraction blended the flying
vapours into one great whole, which floated above the mouth of the
burning mountain.

"And I might have been somewhere on the slope, when that burst of stones
was falling," thought Oliver. "Still, I might climb up a hundred times,
and no eruption occur. I'm getting cowardly, instead of being
accustomed to the place."

He smiled to himself as he marked the top of the mountain, and aimed as
straight as he could for its side, before plunging again into the
bewildering maze of trees, whose wide-spreading foliage made all beneath
a subdued shade.

But a dozen steps had not been taken before he stopped short, with his
heart beating, and listened eagerly, for a distant shout had fallen upon
his ear, coming as he felt sure from behind him, and to the right.

Then there was utter silence for a few seconds, before a second shout
arose, to be heard plainly enough, but away to his left.

His heart sank again, and the hope died out. That was no cry uttered by
one of his companions, but came from a savage, or some wild beast, which
he could not say, but he suspected that it must be from one of the apes
of which they had seen specimens that morning.

There it was again, rather a human cry, such as a boy might give vent to
in a wood, when calling to his fello