“What do you mean?”

But Frank put an end to the jar quickly.

“Tut, tut!” he cried. “Don’t let me hear anything of that kind. This is a poor time for quarreling!”

“I am sure,” said Von Bulow; “I think we are well fixed for the emergency before us.”

“So do I,” said Frank; “the chances for our own escape are very good.”

“About one in a million,” said Bell, sarcastically.

“At least we can preserve life for a good long period aboard the Dart,” said Von Bulow. “We have provisions enough for a year, eh, Frank?”

“I think so,” agreed the young inventor. “And much longer if we economize.”

“But we could never live a year in these close quarters on this artificial air,” growled Bell.

This was the real horror of their situation. It was not at all unlikely that the chemicals would give out before many weeks.