[151] See Winchell's "Sketches of Creation," chap. xxxvi.
[152] Proctor, "Other Worlds than Ours," p. 193. "More likely these have been totally absorbed by the lunar rocks."—Dr. Winchell.
[153] "Correlation and Conservation of forces," p. 245.
[154] North American Review, Oct., 1861, pp. 372-3.
[155] Mitchell's "Planetary and Stellar Worlds," p. 143.
[156] Tyndall, "Fragments of Science," p. 135.
[157] Quoted by Mayer, "Celestial Dynamics: Correlation and Conservation of Forces," p. 271.
[158] "Outlines of Astronomy," p. 308.
[159] Thomson and Tait, "Natural Philosophy," vol. i. p. 191.
[160] Thomson and Tait, "Natural Philosophy," vol. i. p. 191. Balfour Stewart, "Treatise on Heat," p. 372.