looked up at the mighty field of stars that arched over his head to be
lost on either horizon. A wonderful night!

"Where shall we go first, Dick?" asked Wade softly as he gazed out at
the far-off suns of space, his voice unconsciously hushed by the
grandeur of the spectacle.

"I've thought of that for the last four months, and now that we are
definitely going to go, we'll have to make a decision. Actually, it
won't be too hard to decide. Of course we can't leave the solar system.
And the outer planets are so far away that I think we had better wait
till later trips. That leaves the choice really between Mars, Venus, and
Mercury. Mercury isn't practical since it's so close to the sun. We know
a fair bit about Mars from telescopic observation, while Venus, wrapped
in perpetual cloud, is a mystery. What do you vote?"

"Well," said Morey, "it seems to me it's more fun to explore a
completely unknown planet than one that can be observed telescopically.
I vote Venus." Each of the others agreed with Morey that Venus was the
logical choice.

By this time the machine had sunk to the roof of their apartment, and
the men disembarked and entered. The next day they were to start the
actual work of designing the space ship.

II

"When we start this work," Arcot began next morning, "we obviously want
to design the ship for the conditions we expect to meet, and for maximum
convenience and safety. I believe I've thought about this trip longer
than the rest of you, so I'll present my ideas first.

"We don't actually _know_ anything about conditions on Venus, since no
one has actually been there. Venus is probably a younger planet than
Earth. It's far nearer the sun than we are, and it gets twice the heat
we do. In the long-gone time when the planets were cooling I believe
Venus required far longer than Earth, for the inpouring heat would
retard its cooling. The surface temperature is probably about 150
degrees Fahrenheit.

"There is little land, probably, for with the cloud-mass covering Venus
as it does, it's logical to visualize tremendous seas. What life has
developed must be largely aquatic, and the land is probably far behind
us in evolution. Of course, Venus is the planet of mystery--we don't
know; we can only guess. But we do know what things we are going to need
to cross space.

"Obviously, the main driving force will be the power units. These will
get their energy from the rays of the sun by absorbing them in