a compressive resistance almost equal to that
of armor steel. Although so thick, they are crystal clear, and a speck
of dust on the outer surface is easily seen. We have water enough in
tanks to last us three months, or indefinitely if we should have to be
careful, as we can automatically distill and purify all our waste water,
recovering absolutely pure H2O. We have compressed air, also in tanks,
but we need very little, as the air is constantly being purified. Also,
we have oxygen-generating apparatus aboard, in case we should run short.
As to keeping warm, we have electric heating coils, run by the
practically inexhaustible power of a small metal bar. If we get too near
the sun and get too warm, we have a refrigerating machine to cool us
off. Anything else?"

"You'd better give up, Dad," laughingly advised his daughter. "You've
thought of everything, haven't you, Dick?"

"Mart has, I think. This is all his doing, you know. I wouldn't have
thought of a tenth of it, myself."

"I must remind you young folks," said the older man, glancing at his
watch, "that it is very late and high time for Dottie and me to be going
home. We would like to stay and see the rest of it, but you know we must
be away from here before daylight."

* * * * *

As they went into the house Vaneman asked:

"What does the other side of the moon look like? I have always been
curious about it."

"We were not able to see much," replied Crane "It was too dark and we
did not take the time to explore it, but from what we could see by means
of our searchlights it is very much like this side--the most barren and
desolate place imaginable. After we go to Mars, we intend to explore the
moon thoroughly."

"Mars, then, is your first goal? When do you intend to start?"

"We haven't decided definitely. Probably in a day or two. Everything is
ready now."

As the Vanemans had come out in the street car, in order to attract as
little attention as possible, Seaton volunteered to take them home in
one of Crane's cars. As they bade Crane goodnight after enjoying Shiro's
"suitable refreshment" the lawyer took the chauffeur's seat, motioning
his daughter and Seaton into the closed body of the car. As soon as they
had started Dorothy turned in the embrace of her lover's arm.

"Dick," she said fiercely. "I would have been worried sick if I had
known that you were way off there?"

"I knew it, sweetheart. That's why I didn't tell