"Good! Now, when can you begin? As I told you, Mars is already
beginning to move away from us at the rate of twenty-eight
millions of miles a year. That is over two millions of miles a
month, and every day counts."

"We will start at once," promised Mr. Henderson. "That is, if
Jack and Mark decide they want to go. I will let them choose.
Boys, do you want to try to go to Mars, or go back to college?"

"Mars! Every time!" cried Jack. "I want to begin to weigh
less."

"I'll go wherever Jack goes," said Mark.

"Very well, then," assented the professor. "But you must
remember, Mr. Roumann, that I am still unconvinced that you
possess the secret of a power that will project a heavy object
through space to Mars--thirty-five millions of miles away. I do
not say it can't be done, only I want to be shown. I will aid
you all I can, and I will accompany you. But I fear we shall
never get to Mars."

"And I tell you we will!" insisted the other. "Come, I will
prove it to you by mathematics, and by illustrating some of the
force of my new secret power. Let us go to the laboratory."

The professor took from a valise, which sat in a corner of the
room, a bundle of papers. Then, followed by the professor and
the boys, he started for the private laboratory of Mr. Henderson.