"Go to Mars!" exclaimed Mark.

"Thirty-five million miles!" exclaimed Jack with awe in his
tones. "How can we ever cover that distance? No airship ever
made would do it."

"Not an airship, perhaps," said Mr. Roumann, "but something
else. I will tell you how--"

"Perhaps I had better explain from the beginning," interrupted
Mr. Henderson.

"Maybe it will be better," assented the other.

"Boys, be seated," spoke their guardian, and Jack and Mark took
chairs. "Mr. Santell Roumann is an inventor, like myself," went
on Mr. Henderson. "I have known him for several years, but I had
not seen him in a long time, until he called on me the other day
with his strange proposition. We used to attend the same
college, but since his graduation he has been experimenting in
Germany."

"Where I discovered the secret of the wonderful power that will
take us to Mars," added Mr. Roumann.

"That is one point on which we differ," continued Mr. Henderson.
"Mr. Roumann believes we can get to the red planet, which, as he
correctly says, is nearer to us now than it will be again in many
years. I do not see how we can get there through the intervening