surface we see an immense number of lines geometrically arranged, with
a system of symmetrical intersections where the lines expand into
circular and oval areas -- and all connected with the annual melting
of the polar snows in a way which irresistibly suggests the
interference of intelligence directed to a definite end. Why, with so
many concurrent circumstances to support the hypothesis, should we not
regard Mars as an inhabited globe?

But the differences between Mars and the earth are in many ways as
striking as their resemblances. Mars is relatively small; it gets less
than half as much light and heat as we receive; its atmosphere is so
rare that it would be distressing to us, even if we could survive in
it at all; it has no lakes, rivers, or seas; its surface is an endless
prairie. and its ``canals'' are phenomena utterly unlike anything on
the earth. Yet it is precisely upon these divergences between the
earth and Mars, this repudiation of terrestrial standards, that the
theory of ``life on Mars,'' for which Mr Lowell is mainly responsible,
is based. Because Mars is smaller than the earth, we are told it must
necessarily be more advanced in planetary evolution, the underlying
cause of which is the gradual cooling and contraction of the planet's
mass. Mars has parted with its internal heat more rapidly than the
earth; consequently its waters and its atmosphere have been mostly
withdrawn by chemical combinations, but enough of both yet remain to
render life still possible on its surface. As the globe of Mars is
evolutionally older than that of the earth, so its forms of organic
life may be proportionally further advanced, and its inhabitants may
have attained a degree of cultivated intelligence much superior to
what at present exists upon the earth. Understanding the nature and
the causes of the desiccation of their planet, and possessing
engineering science and capabilities far in advance of ours, they may