the geological
periods, now mineralised and transformed into coal; for me they are an
inexhaustible mine."

"Your men follow the trade of miners here, then, Captain?"

"Exactly so. These mines extend under the waves like the mines of
Newcastle. Here, in their diving-dresses, pick axe and shovel in hand,
my men extract the coal, which I do not even ask from the mines of the
earth. When I burn this combustible for the manufacture of sodium, the
smoke, escaping from the crater of the mountain, gives it the
appearance of a still-active volcano."

"And we shall see your companions at work?"

"No; not this time at least; for I am in a hurry to continue our
submarine tour of the earth. So I shall content myself with drawing
from the reserve of sodium I already possess. The time for loading is
one day only, and we continue our voyage. So, if you wish to go over
the cavern and make the round of the lagoon, you must take advantage of
to-day, M. Aronnax."

I thanked the Captain and went to look for my companions, who had not
yet left their cabin. I invited them to follow me without saying where
we were. They mounted the platform. Conseil, who was astonished at
nothing, seemed to look upon it as quite natural that he should wake
under a mountain, after having fallen asleep under the waves. But Ned
Land thought of nothing but finding whether the cavern had any exit.
After breakfast, about ten o'clock, we went down on to the mountain.

"Here we are, once more on land," said Conseil.

"I do not call this land," said the Canadian. "And besides, we are not
on it, but beneath it."

Between the walls of the mountains and the waters of the lake lay a
sandy shore which, at its greatest breadth, measured five hundred feet.
On this soil one might easily make the tour of the lake. But the base
of the high partitions was stony ground, with volcanic locks and
enormous pumice-stones lying in picturesque heaps. All these detached
masses, covered with enamel, polished by the action of the
subterraneous fires, shone resplendent by the light of our electric
lantern. The mica dust from the shore, rising under our feet, flew
like a cloud of sparks. The bottom now rose sensibly, and we soon
arrived at long circuitous slopes, or inclined planes, which took us
higher by degrees; but we were obliged to walk carefully among these
conglomerates, bound by no cement, the feet slipping on the glassy
crystal, felspar, and quartz.

The