H. F. Walling

“ At present it is well understood that all terrestrial motive power is derived from this source with the single unimportant exception of that obtained from the tides, at the expense of the earth's energy of rotation. Among the more obvious processes of conversion of the sun's molecular into terrestrial molar motion, are the expansion and contraction of the atmosphere, the evaporation and condensation of water, and the less direct method by restoration of potential chemical energy accomplished in vegetation, whence are produced food and fuel. ”

“ And so we may suppose combination to follow combination, until, finally, perhaps at a time when the planets, freighted with their living inhabitants, have begun to arrive at the sun's surface, long after the fires of the last combustion have expired, it has itself become a habitable globe, lighted and heated or served by other molecular forces from distant orbs where new conditions cause new chemical combinations, and conversions of newly-developed potential energies. ”

“ Thus the moon may be gradually elongated into a closed ring which will slowly contract upon the earth as the energy of angular velocity is gradually dissipated by the friction of the medium. In any event there seems to be no good reason to suppose that there will be such a sudden leap in the final osculation or embrace as would result in a catastrophe.
The same considerations apply to the gravitational relations between planets and suns. Other very important relations between these bodies, however, with which organic life is more especially concerned, require attention. ”

“ Finally, giving play to the imagination, may we not suppose further, that, in a universe extended throughout infinite space, processes of concentration similar to those supposed in the nebular hypothesis and supplemented by processes like those here indicated will go on forever, evolving worlds of continually-increasing magnificence, perhaps inhabited by living occupants of inconceivably transcendent and ever-expanding faculties? ”

“ Accordingly, the power to produce mechanical motion, exerted by the heat of the sun, which is being lavished with such prodigious prodigality, can only last while the sun continues to be hotter than the other bodies in space. ”

“ It may be added that molecular energy, existing mainly in the form called heat, tends to equalization of dynamic equilibrium, after the attainment of which it is powerless to produce molar or mechanical motion, a reconversion from the condition of equilibrium being impossible. ”

“ The integrity of cosmical evolution in relation to organic life, accordingly, seems to require the maintenance of great central laboratories where molecular disturbances of sufficient intensity and quantity can be continually generated, and their effects distributed throughout the universe. ”

“ The investigations of Hopkins, Thomson, and recently of Barnard, in regard to tidal and precessional influences, indicate that, even at the present distance of the moon, they must cause elongations and contractions of the solid materials of the earth, which are quite appreciable. A considerable diminution of the distance between the earth and moon would give rise to changes in the form of the earth, and hence to bendings to and fro of its external shell even if the earth were solid throughout. ”

“ But it is supposed that the sun will finally grow cold, and that the resistance of the ethereal medium, the evidence of whose existence is found in the demonstration of the undulatory theory of light, will cause satellites to fall into planets, planets into suns, and suns into one common centre, after which, unless by special interposition of divine power, darkness, silence, and death, will forever prevail. ”

“ Notwithstanding the enormous expenditure of heat by the sun, its temperature is supposed to have been maintained about the same as at present for a very long period of time in the past, and no reason is manifest why this fixed temperature will not continue for a very long time in the future. Doubtless, operations are going on in the sun which it would be impossible to imitate in terrestrial laboratories. ”

“ The only practical evidence which has been adduced to prove the resistance of a medium, namely, a very slight diminution in the period of that nearly evanescent body, Encke's Comet, is very far from being definite and satisfactory. The mass of the moon being enormously greater, it is probable that many millions of years will pass before a diminution of her orbital period from this cause will be perceptible. ”

“ The immense periods of time attributed to the past processes of geological evolution, and to the supposed metamorphoses of organic life, are therefore very brief when compared with those required for the returns of satellites to their parent orbs, admitting, as theoretical considerations seem to require, that such returns are ultimately inevitable. ”

“ The determination of these forms is a problem for the mathematicians. In the absence of analysis, no reason is manifest for supposing that the forms of equilibrium would be materially different just before and just after contact. ”