l right," he said
decisively, as he turned on the stored current that would light the
unknown cavern. "At any rate, I shall be able to report the condition
of things, so that you can advise me what to do, or else my training is
a greater failure than I think."

With this he lifted the bearskin, opened a door thus disclosed, and
found himself in a small, well-lighted cavern that was at once a dynamo
room, a workshop, and a storehouse for a confused miscellany of
articles. Without pausing to investigate any of these he went directly
to a dynamo that had been set up at one side and examined it carefully.
It appeared in perfect order, and the trouble must evidently be sought
elsewhere.

Cabot had wondered by what power the dynamo was driven, and now,
hearing a sound of running water, he stepped in that direction. A
short distance away he discovered a swift-flowing subterranean stream,
in which revolved a water wheel of rude, but serviceable, construction.
As nothing seemed wrong with it, he was obliged to look further, and
finally found the cause of trouble to be a transmitting belt, the
worn-out lacing of which had parted. As portions of the belt itself
had been caught in the pulleys and badly cut, it was necessary to hunt
through the pile of material for a new one, and for leather suitable
for lacing. Then the new belt must be accurately measured, laced
together, and adjusted to its pulleys.

Although the temperature of the cavern was many degrees above that of
the outside air, it was still so low that Cabot worked slowly and with
numbed fingers. Thus more than an hour had elapsed before the dynamo
was again in running order, and he was at liberty to return to the
living room. In the meantime his curiosity concerning this strange
place of abode and its mysterious tenant was increased by the
remarkable collection of articles stored on all sides. There was no
end of machinery, tools, and electrical apparatus of all kinds,
including miles of copper wire and chemicals for charging batteries.
Besides these, there were ropes, canvas, furniture, boxes, barrels, and
other things too numerous to mention.

"What a prize this place would have been for the Indians if they had
ever discovered it," reflected the young engineer. "I wonder that he
dared go off and leave it unguarded."

When he finally returned to the outer room, he found it even colder
than the cavern in which he had been working, and realised, as never
b