Dr. Herschel, in another paper, sup poses that the spots in the sun are moun tains on its surface, which, considering the great attraction exerted by the sun upon bodies placed at its surface, and the slow revolution it has about its axis, he thinks may be more than 300 miles high, and yet stand very firmly. He says, that in August 1792, be examined the sun with several powers, from 90 to 500. And it evidently appeared that the black spots are the opaque ground or body of the sun; and that the luminous part is an atmosphere, which, being intercepted or broken, gives us a glimpse of the sun it self Hence he concludes that the sun has a very extensive atmosphere, which con sists of elastic fluids that are more or less lucid and transparent ; and of which the lucid ones furnish us with light. This at mosphere he thinks is not less than 1843 nor more than 2765 miles in height and be supposes that the density of the lumi nous solar clouds need not b e exceedingly more than that of our aurora borealis, in order to produce the effects with which we are acquainted.
The sun,then, appears to be a very emi nent, large, and lucid planet, evidently the first and only primary one belonging to our system. Its similarity to the other globes of the solar system, with regard to Its solidity; its atmosphere ; its surface diversified with mountains and vallies ; its rotation on its exis ; and the fall of heavy bodies on its surface ; leads us to suppose that it is most probably inhabited, like the rest of the planets, by beings whose organs are adapted to the peculiar cir cumstances of that vast globe. if it be objected that, from the effects produced at the distance of 95,000,000 miles, we may infer that every thing must be scorched up at its surface ; we reply, that there are many facts in natural phi losophy, which show that heat is pro duced by the sun's rays only when they act on a calorific medium : they are the oause of the production of heat, by unit ing. with the matter of fire which is con tained in the substances that are heated ; as the collision of the flint and steel will inflame a magazine of gunpowder, by putting all the latent fire which it con tains into action. On the tops of moun tains of sufficient height, at the altitude where clouds can seldom reach to shelter them from the direct rays of the sun, we always find regions of ice and snow. Now, if the solar rays themselves convey ed all the heat we find on this globe, it ought to be hottest where their course is the least interrupted. Again, our aeronauts all confirm the coldness of the upper regions of the atmosphere ; and since, therefore, even on our earth, the heat of the situation depends upon the readiness of the medium to yield to the impression of the solar rays, we have on ly to admit, that on the sun itself the elastic fluids competing its atmosphere, and the matter on its surface, are of such a nature as not to be capable of any ex tensive affection of its own rays ; and this seems to be proved by the copious emis sion of them ; for if the elastic fluids of the atmosphere, or of the matter contain ed on the surface of the sun, were of such a nature as to admit of an easy chemical combination with its rays, their emission would be very much impeded. Another
well known fact is, that the solar focus of the largest lens thrown into the air will occasion no sensible heat in the place where it has been kept for a consider able time, although its power of exciting combustion, when proper bodies are ex posed, should be sufficient to fuse the most refractory substances.
It is by analogical reasoning that we con sider the moon as inhabited. For it is a se condary planet of considerable size, its surface is diversified like that of the earth with hills and Its situation with respect to the sun is much like that of the earth ; and by a rotation on its axis it enjoys an agreeable variety of seasons, and of day and night. To the moon our globe would appear • capital satellite, un dergoing the same changes of illumina tion as the moon does to the earth. The sun, planets, and the starry constellations of the heavens, will rise and set there as they do here : and heavy bodies will fall on the moon as they do on the earth. There seems, then, only to be wanting, in order to complete the analogy, that it should be inhabited like the earth. It may be objected, that, in the moon, there are no large seas ; and its atmosphere (the existence of which is doubted by many) is extremely rare, and unfit for the pur. poses of animal life ; that its climates, its seasons, and the length of its days and nights, totally differ from ours; that with. out dense clouds, which the moon has not, there can be no rain, perhaps no ri vers and lakes. In answer to this it may be observed, that the very difference be. tween the two planets strengthens the argument. We find, even on our own globe, that there is a most striking dissi milarity in the situation of the creatures that live upon it. While man walks on the ground, the birds fly in the air, and the fishes swim in the water. We cannot surely object to the conveniencies afford ed by the moon, if those that are to in habit its regions are fitted to their con ditions as well as we on this globe of ours. The analogy already mentioned esta blishes a high probability that the moon is inhabited.