Page:The fairy tales of science.djvu/220

essential analogies between our own and the other planets before our mind, how can we doubt but that those other “celestial structures” have been made, provided, and fitted by God to be the abodes of sentient beings kindred to the denizens of our earth? As direct evidence of the fact, however, remains as yet still denied us, attempts have not been, and even now are not wanting to throw doubt on the correctness of this inference from our analogical reasoning. But most of the “arguments” adduced against the supposition of the planets being inhabitable globes like our earth are of too flimsy and futile a nature to be deserving even of a passing allusion; others have been convincingly refuted. Thus, to give an instance, it has been advanced that Jupiter, Saturn, Uranus, and Neptune, being severally five, nine, eighteen, and twenty-eight times farther removed from the sun than our earth, the heating and illuminating power of the solar rays must be in these large planets respectively 25, 81, 324, and 784 times less than on our globe, which would preclude the possibility of the existence on them of beings organized like the denizens of earth. The simple consideration, however, that a mere enlargement of the pupil of the eye in the ratio of the diminution of the apparent superficial magnitude of the sun’s disk as respectively beheld from these planets, or a proportionally increased sensibility of the retina, would leave the illuminating power of the sun the same as at the earth; and that in like manner the diminished calorific power of the solar rays