Page:Is Mars habitable - Wallace 1907.djvu/18

 —Mr. Lowell's investigation of the problem—Abstract of Mr. Lowell's paper—Critical remarks on Mr. Lowell's paper.

CHAPTER VI.


 * Langley's determination of lunar heat—Rapid loss of heat by radiation on the earth—Rapid loss of heat on moon daring 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.


 * 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.