of all. If we look at her even with the naked eye, we can see
that she is elongated or drawn out, but her brilliance prevents us from
seeing her shape exactly; to do this we must use a telescope.

[Illustration: DIFFERENT PHASES OF VENUS.]

It is a curious fact that some planets shine much more brightly than
others, without regard to their size--that is to say, the surface on
which the sun's rays strike is of greater reflecting power in some than
in others. One of the brightest things in Nature that we can imagine is
a bank of snow in sunlight; it is so dazzling that we have to look away
or wink hard at the sight; and the reflective power of the surface of
Venus is as dazzling as if she were made of snow. This is probably
because the light strikes on the upper surface of the clouds which
surround her. In great contrast to this is the surface of Mercury, which
reflects as dully as a mass of lead. Our own moon has not a high
reflecting power, as will be easily understood if we imagine what the
world would be if condemned to perpetual moonlight only. It would,
indeed, be a sad deprivation if the mournful cold light of the moon,
welcome enough as a change from sunlight, were to take the place of
sunlight in the daytime.

For a very long time astronomers could not discover what time Venus took
in rotating on her own axis--that is to say, what the length of her day
was. She is difficult to observe, and in order to find out the rotation
it is necessary to note some fixed object on the surface which turns
round with the planet and comes back to the same place again, so that
the time it takes in its journey can be measured. But the surface of
Venus is always changing, so that it is impossible to judge at all
certainly. Opinions differ greatly, some astronomers holding that
Venus's day is not much longer than an earthly day, while others believe
that the planet's day is equal to her year, just as in the case of
Mercury. Venus's year is 225 days, or about seven and a half of our
months, and if, indeed, her day and year are the same length, very
peculiar effects would follow. For instance, terrible heat would be
absorbed by the side of the planet facing the sun in the perpetual
summer; and the cold which would be felt in the dreary winter's night
would far exceed our bitterest Arctic climate. We cannot but fancy that
any beings who might live on a planet of this kind must be different
altogether from ourselves. Then, there is ano