"I guess that crazy Axtell fellow was only joking when he said we'd
never reach the moon," ventured Jack. "Nothing has happened yet."

"Only the meteor," said Mark, "and he couldn't know about that. I guess
he didn't get a chance to damage any of the machinery."

"No, we seem to be making good time," went on his chum. "I think I'll
go and----"

Jack did not finish his sentence. Instead he stared at one of the
instruments hanging from the walls of the engine room. It was a sort of
barometer to tell their distance from the earth, and it swung to and
fro like a pendulum. Now the instrument was swinging out away from the
wall to which it was attached. Further and further over it inclined.
Jack felt a curious sensation. Mark put his hand to his head.

"I feel--feel dizzy!" he exclaimed. "What is the matter?"

"Something has happened," cried Jack.

The instrument swung over still more. Some tools fell from a work
bench, and landed on the steel floor with a crash. The boys were
staggering about the engine room, unable to maintain their balance.

There came cries of fear from the galley, where Washington White was
rattling away amid his pots and pans. Andy Sudds was calling to some
one, and from the pilot-house came the excited exclamations of
Professors Henderson and Roumann.

"We're turning turtle!" suddenly yelled Jack. "The projectile is