indicate, then, that Venus has about as much as the earth, wouldn't it?"
remembering how the home planet had looked when they left it.

The doctor nodded. "There are other factors; but undoubtedly we are
approaching a world which is a great deal like our own. Venus is nearly
as large as the earth, has about nine-tenths the surface, and a gravity
almost as strong. The main difference is that she's only two-thirds as
far from the sun as we are."

"How long is her day?" Smith wanted to know.

"Can't say. Some observers claim to have seen her clearly enough to
announce a day of the same length as ours. Others calculate that she's
like Mercury; always the same face toward the sun. If so, her day is
also her year--two hundred and twenty-five of our days."

Van Emmon looked disappointed. "In that case she would be blistering hot
on one side and freezing cold on the other; except," remembering
Mercury, "except for the 'twilight zone,' where the climate would be
neither one nor the other, but temperate." He pointed to the line down
the middle of the disk before them, the line which divided the lighted
from the unlighted, the day from the night.

The four looked more intently. It should be remembered that the very
brilliance of Venus has always hindered the astronomers; the planet as a
whole is always very conspicuous but its very glare makes it impossible
to see any details. The surface has always seemed to be covered by a
veil of hazy, faintly streaked vapor.

Smith gave a queer exclamation. For a moment or two he stared hard at