“We’re not liable to have any accidents with the professor in charge,” Jack answered. “Didn’t he bring us safe out of some pretty tight holes when we went to the north pole in the airship, and again when we found the south pole in the submarine?”
“Yes, but this is different,” objected Mark.
“Well, I’m not worrying,” Jack went on. “It doesn’t do any good, and only makes you lie awake nights. By the way, I wonder what time it is getting to be.”
He looked at his watch and found it was close on to eight o’clock in the evening. So late had dinner been served, and so varied were the happenings of the last few hours, that time had passed quickly.
“Why it’s almost bed-time,” said Jack. “I wonder if we are to go on dropping into the depths of nowhere all night.”
At that moment the professor entered the room where the boys were. He seemed quite pleased over something, and was smiling.
“Everything is going along famously,” he said. “I have just tested the air and find it is rich in oxygen. We shall suffer nothing on that score. The heat too, seems to have decreased. On the whole, everything favors us.”
“Are we going on down?” asked Mark.
“As far as we can,” Mr. Henderson answered. “Let me see how far we are below now.”
He went to the gage that indicated the vertical position of the ship. Because of the changed conditions, the craft now sinking below the surface of the earth instead of rising above it, as was its wont, some calculations were necessary. These the scientist made as quickly as he could.