"In the cavern back of this room. The doorway is behind that bearskin. This upper row of keys connects with the storage battery, and the second key controls the lights of the dynamo room. If there is a bad break I can manage to get to it, but I wouldn't try until you came, because I promised not to move."
All this was said in a voice that faltered from weakness, and a wave of pity surged in Cabot's breast as he realised how dependent upon him this man, so recently a mental as well as a physical giant, had become.
"I expect I shall be able to attend to it all 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 before, the value of the knowledge that had enabled him to restore the usefulness of that electric heater. After getting it into operation, and making his report to the sick man, who had impatiently awaited him, there was another meal to prepare.
So, in spite of Cabot's overwhelming desire to hear Mr. Balfour's story, there was so much to be done first that the short day had merged into another night before the opportunity arrived. When it came, our lad drew a chair to the bedside of his patient and said:
"Now, sir, if you feel able to talk, and are willing to tell me how you happen to be living in this place, I shall be more than glad to listen."