CHAPTER IV.
IS ANIMAL LIFE POSSIBLE ON MARS?
—Water and air essential for animal life
—Atmosphere of Mars assumed to be like ours
—Blue tint near melting snow the only evidence
of water
—Fallacy of this argument
—Dr. Johnstone Stoney's proof that water-vapour
cannot exist on Mars
—Spectroscope gives no evidence of water.
CHAPTER V.
TEMPERATURE OF MARS—MR. LOWELL'S ESTIMATE,
—Problem of terrestrial temperature
—Ice under recent lava
—Tropical oceans ice-cold at bottom
—Earth's surface-heat all from the sun
—Absolute zero of temperature
—Complex problem of planetary temperatures
—Mr. Lowell's investigation of the problem
—Abstract of Mr. Lowell's paper
—Critical remarks on Mr. Lowell's paper.
CHAPTER VI.
A NEW ESTIMATE OF THE TEMPERATURE OF MARS,
—Langley's determination of lunar heat
—Rapid loss of heat by radiation on the
earth
—Rapid loss of heat on moon during eclipse
—Sir George Darwin's theory of the moon's origin
—Very's researches on the moon's temperature
—Application of these results to the case of Mars
—Cause of great difference of temperatures of earth
and moon
—Special features of Mars influencing its
temperature
—Further criticism of Mr. Lowell's article
—Very low temperature of arctic regions on Mars.
CHAPTER VII.
A SUGGESTION AS TO THE 'CANALS' OF MARS,
—Special features of the canals
—Mr. Pickering's suggested explanation
—The meteoritic hypotheses of origin of planets
—Probable mode of origin of Mars
—Structural straight lines on the earth
—Probable origin of the surface-features of Mars
—Symmetry of basaltic columns
—How this applies to Mars
—Suggested explanation of the oases
—Probable function of the great fissures
—Suggested origin of blue patches adjacent to snow-caps
—The double canals
—Concluding remarks on the canals.
CHAPTER VIII.
PAGE SUMMARY AND CONCLUSION,
—The canals the origin of Mr. Lowell's theory
—Best explained as natural features
—Evaporation difficulty not met by Mr. Lowell
—How did Martians live without the canals
—Radiation due to scanty atmosphere not taken account
of
—Three independent proofs of low temperature and
uninhabitability of Mars
—Conclusion.