Is Mars habitable? A critical examination of Professor Percival Lowell's book "Mars and its canals," with an alternative explanation

by Alfred Russel Wallace

Incidentally, also, I have been led to an explanation of the highly volcanic nature of the moon's surface. This seems to me absolutely to require some such origin as Sir George Darwin has given it, and thus furnishes corroborative proof of the accuracy of the hypothesis that our moon has had an unique origin among the known satellites, in having been thrown off from the earth itself.

I am indebted to Professor J. H. Poynting, of the University of Birmingham, for valuable suggestions on some of the more difficult points of mathematical physics here discussed, and also for the critical note (at the end of Chapter V.) on Professor Lowell's estimate of the temperature of Mars.

BROADSTONE, DORSET, October 1907.

TABLE OF CONTENTS.

CHAPTER I.

EARLY OBSERVERS OF MARS,
—Mars the only planet the surface of which is
distinctly visible
—Early observation of the snow-caps and seas
—The 'canals' seen by Schiaparelli in 1877
—Double canals first seen in 1881
—Round spots at intersection of canals seen
by Pickering in 1892
—Confirmed by Lowell in 1894
—Changes of colour seen in 1892 and 1894
—Existence of seas doubted by Pickering and
Barnard in 1894.

CHAPTER II.

MR. LOWELL'S DISCOVERIES AND THEORIES,
—Observatory at Flagstaff, Arizona
—Illustrated book on his observations of
Mars
—Volume on Mars and its canals, 1906
—Non-natural features
—The canals as irrigation works of an intelligent
race
—A challenge to the thinking world
—The canals as described and mapped by Mr. Lowell
—The double canals
—Dimensions of the canals
—They cross the supposed seas
—Circular black spots termed oases
—An interesting volume.

CHAPTER III.

THE CLIMATE AND PHYSIOGRAPHY OF MARS,
—No permanent water on Mars
—Rarely any clouds and no rain
—Snow-caps the only source of water
—No mountains, hills, or valleys on Mars
—Two-thirds of the surface a desert
—Water from the snow-caps too scanty to supply
the canals
—Miss Clerke's views as to the water-supply
—Description of some of the chief canals
—Mr. Lowell on the purpose of the canals
—Remarks on the same
—Mr. Lowell on relation of canals to oases and
snow-caps
—Critical remarks on the same.