house.

There, consulting big charts of the heavens, and by making some
intricate calculations, which the boys partly understood, the German
and Mr. Henderson were able to locate the exact position of the moon,
though that body was not then in sight, being behind the earth.

"That ought to bring us there inside of a week," announced Mr.
Henderson, as he fastened the automatic steering apparatus in place.
"The projectile will now be held on a straight course, and I hope we
shall not have to change it."

"Could anything cause us to swerve to one side?" asked Jack.

"Sure," replied Mark. "Don't you remember how, in the trip to Mars, we
nearly collided with the comet? If we are in danger of hitting another
one of those things, or even a meteor, we'll steer out of the way,
won't we?"

"Of course. I forgot about that," admitted Jack.

"Yes," declared Professor Roumann, "we'll have to be on the lookout for
wandering meteors or other stray heavenly bodies. But our instruments
will give us timely warning of them. Now, I think we can leave the
projectile to herself while I make sure that all the machinery is
running smoothly. You boys may stay here if you like, though there
isn't much to see."

There wasn't. It was totally unlike taking a trip on earth, where the
ever-varying scenery makes a journey pleasant. There was no landscape