descending and
creeping into a fissure in the rocks, I found beneath the surface a
cavern precisely resembling the remains that existed above ground, only
that this was roofed, whilst through it ran a small stream which in the
rainy season must become a perfect torrent. It was now evident to me that
ere many years had elapsed the roof would give way, and what now were the
buttresses of dark and gloomy caverns would emerge into day and become
columns clad in green, and resplendent in the bright sunshine.

GRADUAL DEGRADATION OF THE LAND.

In this state they would gradually waste away beneath the ever-during
influence of atmospheric causes, and the material being then carried down
by the streams, through a series of caverns resembling those of which
they once formed a portion, would be swept out into the ocean and
deposited on sandbanks, to be raised again, at some remote epoch, a new
continent, built up with the ruins of an ancient world.

I subsequently, during the season of the heavy rains, remarked the usual
character of the mountain streams to be that they rose at the foot of
some little elevation which stood upon a lofty tableland composed of
sandstone, then flowed in a sandy bed for a short distance and afterwards
mysteriously sank in the cracks and crevices made in the rocks from
atmospheric influences, and did not again reappear until they had reached
the foot of the precipice which terminated the tableland whence they
sprang; here they came foaming out in a rapid stream which had
undoubtedly worked strange havoc in the porous sandstone rocks among
which it held its subterraneous course.

What the amount of sand annually carried down from the north-western
portion of Australia into the ocean may be we have no means whatever of
ascertaining; that it is sufficient to form beds of sand of very great
magnitude is attested by the existence of numerous and extensive
sandbanks all along the coast. One single heavy tropical shower of only a
few hours' duration washed down, over a plot of ground which was planted
with barley, a bed of sand nearly five inches deep, which the succeeding
showers again swept off, carrying it further upon its way towards the
sea.

The space of ground covered with these columns gradually contracted its
dimensions as we proceeded; the columns themselves became nearer and
nearer to each other until they at length formed walls of cliffs on each
side of us, and we finally reached a point wher