VOL. LXXXV.] PHILOSOPHICAL TRANSACTIONS. 489 



not to be capable of any excessive affection from its own rays; and indeed this 

 seems to be proved by the copious emission of them ; for if the elastic fluids of 

 the atmosphere, or the matter contained on the surface of the sun, were of such 

 a nature as to admit of an easy chemical combination with its rays, their emis- 

 sion would be 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 considerable time, though its power of exciting combustion, when proper 

 bodies are exposed, should be sufficient to fuse the most refractory substances. 

 It will not be necessary to mention other objections, as I can think of none that 

 may be made, but what a proper consideration of the foregoing observations will 

 easily remove; such as maybe urged from the dissimilarity between the luminous 

 atmosphere of the sun and that of our globe will be touched on hereafter, when 

 I consider the objections that may be assigned against the moon's being an inha- 

 bitable satellite. 



I shall now endeavour, by analogical reasonings, to support the ideas I have 

 suggested concerning the construction and purposes of the sun; in order to 

 which, it will be necessary to begin with such arguments as the nature of the 

 case will admit, to show that our moon is probably inhabited. This satellite is 

 of all the heavenly bodies the nearest, and therefore most within the reach of 

 our telescopes. Accordingly we find, by repeated inspection, that we can with 

 perfect confidence give the following account of it. It is a secondary planet, of 

 a considerable size; the surface of which is diversified, like that of the earth, by 

 mountains and valleys. 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 will appear to be a very 

 capital satellite; undergoing the same regular changes of illuminations as the 

 moon does to the earth. The sun, the 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 only to be wanting, in order 

 to complete the analogy, that it should be inhabited like the earth. 



To this it may be objected, that we perceive no large seas in the moon; that 

 its atmosphere, the existence of which has even been doubted by manv, is ex- 

 tremely rare, and unfit for the purposes of animal life; that its climates, its sea- 

 sons, and the length of its days, totally differ from ours; that without dense 

 clouds, which the moon has not, there can be no rain; perhaps no rivers, no 

 lakes. In short, that notwithstanding the similarity which has been pointed out, 

 there seems to be a decided difference in the two planets we have compared. My 

 answer to this will be, that that very difference which is now objected, will rather 

 strengthen the force of my argument, than lessen its value: we find, even on 



VOL. XVII. 3 R r 



