in advance of the
inhabitants of our much younger, and therefore less developed, world!

The lessons to be learned from this, and from the physical conditions
now prevailing on the planet, are very similar.

Mars, gradually, but inevitably, becoming a vast desert, and with the
end of all things certain to arrive in a comparatively near future,
pictures to us what must as inevitably be the fate of our own world ages
hence, unless it come to an untimely end by some catastrophe.

As Professor Lowell has pointed out, we know we have an abundant supply
of water at the present time, but we also know that, ages ago, the area
of our world covered with water was immensely greater than it is now.
From the very beginning of our world's existence the process of
diminution of the water area has always gone on, and it will still go
on--slowly, surely, and continually.

As an inevitable result of this decrease of water, and other natural
conditions, vast areas of land on both sides of our tropical zones have
become deserts; and it is a scientific certainty that this process of
desertism will, and must continue, until it covers the whole world.

But, I think, the end will long be delayed, for the loss by desertism
will, as it seems to me, for ages be compensated by the new and
habitable land arising from areas now covered by water. The old sea-beds
upon Mars are now the most fertile areas upon that planet.

As the desertism increases conditions similar to those of Mars will
arise; the earth will become more level, polar glaciation will cease,
the atmosphere become thinner, and water vapour, instead of falling as
rain, will be carried by circulatory currents to the poles, and there be
deposited as snow. What the Martians have accomplished has shown us how
to stave off the water difficulty, and also how a highly civilised and
intelligent people can bravely and calmly face the end which they
clearly foresee!

This is the lesson from the present physical condition of Mars.

On the other hand, the continual progress of civilisation upon Mars, and
the very high development attained there, coupled with what we know of
our own progress during the ages past, give certainty to the hope that
our own civilisation will continue to develop, slowly indeed, but
surely; and also to the belief that, compared to what it will be in the
future, our present stage of civilisation is merely savagery.

Development will lead to progress in everything