or we would be delayed longer."

"Still two weeks is quite a while," suggested Mark. "Perhaps there'll
be no diamonds left on the moon when we get there, Jack," and he smiled
jokingly.

"Oh, I fancy there will. The article in the paper from Mars says there
was a whole field of them."

"This brings up another matter," said Professor Henderson. "What will
happen if we bring back bushels and bushels of diamonds?--which, in
view of what the paper says, may be possible. We will swamp the market,
and the value of diamonds will drop."

"Then we must not throw them upon the market," decided Professor
Roumann. "The scarcity of an article determines its value. If we do
find plenty of diamonds, it will give me a chance to conduct some
experiments I have long postponed because of a lack of the precious
stones. We can use them for laboratory purposes, and need not sell
them. In fact, with the Cardite we brought back from Mars, we have no
lack of money, so we really do not need the diamonds."

It was decided, in view of the shock and upset caused by the explosion,
that no further work would be done that day, and so, after carefully
locking the shed, and posting Andy on guard with his gun, the boys and
the professor went into the house to discuss matters, and plan for work
the next day.

"Mark," said Jack in a low voice, as they followed the two scientists,
"I think it's up to us to try to find that mysterious man who sent the