factory, it will be possible to see lines on
the planet which are not more than one mile in width.

As regards the surface characteristics of Mars, we found that it is
generally very flat, and that only here and there one comes across
slight undulations, whilst hills and mountains are very few indeed.
There are, in fact, no high mountains anywhere; the highest altitudes
rarely approach 2000 feet, and such heights as these are quite
exceptional.

This was quite in accordance with our expectations, because no mountains
have ever been seen upon Mars, though they have been carefully searched
for by our observers. If there were any elevations much exceeding 2000
feet in height they would have been visible sometimes when the planet
was passing under the careful scrutiny of our observers, and they could
not have entirely escaped observation.

In all probability Mars never at any time possessed mountains whose
height would be at all comparable with that of our mountains; for,
according to scientific calculation and reasoning, the planet's internal
heat was never sufficient to have caused the formation of such high
elevations on its crust.

As the planet advanced stage after stage in its development it became
colder and colder; all upheavals ceased, and the height of any elevated
parts upon its surface would thenceforward be gradually and continuously
reduced by weathering and erosion in the same way as has happened in
many places on our own world. We have no very high mountains in the
British Isles at the present time, but geology and physical geography
teach us that many of the low elevations now existing are merely the
basic wrecks and remains of mountains which, in ages past, must have
been of considerable altitude. As the world ages and becomes colder its
surface will tend to become more and more level, and the rivers will
become straighter in consequence.

As regards animals, we discovered that the larger varieties have become
extinct, and that there are at present no animals which can properly be
termed wild or fierce, for they cannot exist in the deserts without
water or vegetation. Numerous animals, however, frequent the irrigated
parts where there is vegetation, and, though in a complete state of
freedom, have for such an extremely long period been in constant contact
with the people that they have become quite tame. The people always
treat animals with kindness, and these free creatures are entirely
without fear