They were literally covered with cog wheels, levers, handles, springs, pieces of machinery, patterns, models, and strange devices. The room had two doors. One was that by which the old man and the negro had entered. The other was behind the bed, and was clamped and fastened with so many bolts and bars, with locks similar to those on big safes, that it would seem a rare treasure was concealed behind the portal.
The old man gave no heed to the wonders that surrounded him. Instead he gave all his attention to the boys. He sat down beside the bed and watched them as their breathing became stronger. From time to time he felt of their pulses, and nodded his head as if satisfied.
"Is the beef tea ready?" asked the old man, after a half hour had passed.
"It am, Perfessor."
"Then turn down the flame a bit so it will keep the stuff warm, and come back into the work shop with me. I want to get that last bolt in the engine."
"Are dem young gen'men all hunky-dory?"
"They are coming on nicely," was the old man's reply. "They will recover consciousness in half an hour and we can feed them, and give them some medicine. Come along, Washington."
The two passed out through the much-locked door behind the bed, the undoing of the fastenings taking some time. As the portal swung open it disclosed a long shed which seemed to be occupied with a big, strange object.
The old professor and the negro had not been gone more than five minutes before Jack opened his eyes. He turned over on one side. As he did so Mark slowly lifted his head.
"Hello!" cried Jack, faintly.