far above that of boiling water."

"Boiling water!" ejaculated Mark. "Wow! That won't be very nice. I
don't want to be boiled like a lobster!"

"Wait a moment," cautioned Mr. Roumann, with a smile. "Later, Lord
Rosse's own investigations, and those of Langley, threw some doubts on
this. There is said to be no air blanket about the moon, as there is
about the earth, so that the moon loses heat as fast as it receives it;
and it now seems more probable that the temperature never rises above
the freezing point of water, just as is the case on our highest
mountains."

"That's better," came from Jack. "We can stand a low temperature more
easily than we can to be boiled; eh, Jack?"

"Sure. But I don't want to be frozen or boiled either, if I can help
it. Guess I'll wear my fur suit that we brought back from the North
Pole with us."

"I agree with you, Professor Roumann, about the temperature," announced
Mr. Henderson, "so we must make up our minds to shiver, rather than
melt. But we are prepared for that."

"What about there being no air on the moon?" asked Jack.

"Oh, we can manufacture our own oxygen," said Mark. "We can walk around
with an air tank on our shoulders, as we did when we went beneath the
surface of the ocean. Now, I guess----"