cold of the lunar night would transcend that
known in the bleakest regions of our earth. The amount of heat radiated
to us by the moon has been investigated by Lord Rosse, and more recently
by Professor Langley. Though every point on the moon's surface is
exposed to the sunlight for a fortnight without any interruption, the
actual temperature to which the soil is raised cannot be a high one. The
moon does not, like the earth, possess a warm blanket, in the shape of
an atmosphere, which can keep in and accumulate the heat received.

Even our largest telescopes can tell nothing directly as to whether life
can exist on the moon. The mammoth trees of California might be growing
on the lunar mountains, and elephants might be walking about on the
plains, but our telescopes could not show them. The smallest object that
we can see on the moon must be about as large as a good-sized cathedral,
so that organised beings resembling in size any that we are familiar
with, if they existed, could not make themselves visible as telescopic
objects.

We are therefore compelled to resort to indirect evidence as to whether
life would be possible on the moon. We may say at once that astronomers
believe that life, as we know it, could not exist. Among the necessary
conditions of life, water is one of the first. Take every form of
vegetable life, from the lichen which grows on the rock to the giant
tree of the forest, and we find the substance of every plant contains
water, and could not exist without it. Nor is water less necessary to
the existence of animal life. Deprived of this element, all organic
life, the life of man himself, would be inconceivable.

Unless, therefore, water be present in the moon, we shall be bound to
conclude that life, as we know it, is impossible. If anyone stationed on
the moon were to look at the earth through a telescope, would he be able
to see any water here? Most undoubtedly he would. He would see the
clouds and he would notice their incessant changes, and the clouds alone
would be almost conclusive evidence of the existence of water. An
astronomer on the moon would also see our oceans as coloured surfaces,
remarkably contrasted with the land, and he would perhaps frequently see
an image of the sun, like a brilliant star, reflected from some smooth
portion of the sea. In fact, considering that much more than half of our
globe is covered with oceans, and that most of the remainder is liable
to be obscured by c