t now the captain wanted light--he cared
not what might happen afterwards. In a very short time, with the lantern
in his hand, which lighted up the cave for a considerable distance about
him, the captain again stood at the foot of the subterranean dome.

He walked around it. He raised and lowered his lantern, and examined it
from top to bottom. It was one half a sphere of masonry, built in a
most careful manner, and, to all appearances, as solid as a great stone
ball, half sunken in the ground. Its surface was smooth, excepting for
two lines of protuberances, each a few inches in height, and about a
foot from each other. These rows of little humps were on opposite
sides of the dome, and from the bottom nearly to the top. It was plain
they were intended to serve as rude ladders by which the top of the
mound could be gained.

The captain stepped back, held up his lantern, and gazed in every
direction. He could now see the roof of the cavern, and immediately above
him he perceived what he was sure were regular joints of masonry, but on
the sides of the cave he saw nothing of the sort. For some minutes he
stood and reflected, his brain in a whirl. Presently he exclaimed:

"Yes, this cave is man's work! I am sure of it. It is not natural. I
wondered how there could be such a cave on the top of a hill. It was
originally a gorge, and they have roofed it over, and the bottom of the
basin has been cut out to make it deeper. It was made so that it could be
filled up with water, and roofed over so that nobody should know there
was any water here, unless they came on it by means of the passage from
our caves. That passage must have been blocked up. As for the great
opening in the side of the cave, the rocks have fallen in there--that is
easy enough to see. Yes, men made this cave and filled it with water, and
if the water were high enough to cover the handle of that machine, as it
was when I struck it, it must also have been high enough to cover up this
stone mound. The lake was intended to cover and hide that mound. And
then, to make the hiding of it doubly sure, the men who built all this
totally covered up the lake so that nobody would know it was here. And
then they built that valve apparatus, which was also submerged, so that
they could let out the water when they wanted to get at this stone
thing, whatever it is. What a scheme to hide anything! Even if anybody
discovered the lake, which would not be likely until some part of