grand chemical laboratory are generally what is loft by the emiffion of light; at work, act upon them; we may therefore admit that in the very extenfive atmosphere of the fun, from caufes of the fame nature, fimilar phænomena will take place; but with this difference, that the continual and very extenfive decompofitions of the elaftic fluids of the fun, are of a phosphoric nature, and attended with lucid appearances, by giving out light. If it fhould be objected, that fuch violent and unremitting decompofitions would exhaust the fun, we may recur again to our analogy, which will furnish us with the following reflections. The extent of our own atmosphere, we fee, is still preserved, notwithstanding the copious decompofitions of its fluids, in clouds and falling rain; in flashes of lightning, in meteors, and other luminous phænomena; because there are fresh fupplies of elastic vapours, continually afcending to make good the wafte oceafioned by thofe decompofitions. But it may be urged, that the cafe with the decompofition of the elaftic fluids in the folar atmosphere would be very different, fince light is emitted, and does not return to the fun, as clouds do to the earth when they defcend in fhowers of rain. To which I anfwer, that in the decomposition of phosphoric fluids every other ingredient but light may also return to the body of the fun. And that the emiffion of light must waste the fun, is not a difficulty that can be oppofed to our hypothefis. For as it is an evident fact that the fun does emit light, the fame objection, if it could be one, would equally militate against every other affignable way to account for the phænomenon. There are moreover confiderations that may leffen the preffure of this alleged difficulty. We know the exceeding fubtility of light to be fuch, that in ages of time its emanation from the fun cannot very fenfibly leffen the fize of this great body. To this may be added, that, very poffibly, there may alfo be ways of restoration to compenfate for though the manner in which this can be brought about should not appear to us. Many of the operations of nature are carried on in her great laboratory, which we cannot comprehend; but now and then we see some of the tools with which fhe is at work. We need not wonder that their conftruction fhould be fo fingular as to induce us to confefs our ignorance of the method of employing them, but we may rest affured that they are not a mere lufus naturæ. I allude to the great number of fmall telescope comets that have been obferved; and to the far greater number still that are probably much too fmall for being noticed by our most diligent fearchers after them. Thofe fix, for inftance, which my fifter has difcovered, I can from examination affirm, had not the least appearance of any folid nucleus, and seemed to be mere collections of vapours condensed about a centre. Five more, that I have alfo obferved, were nearly of the fame nature. This throws & mystery over their destination, which feems to place them in the allegorical view of tools, probably defigned for fome falutary purposes to be wrought by them; and, whether the restoration of what is loft to the fun by the emiffion of light, the poffibility of which we have been mentioning above, may not be one of these purposes, fhall not prefume to determine. The motion of the comet discovered by M. Meffier, in June 1770, plainly indicated how much its orbit was liable to be changed, by the perturbations of the planets; from which, and the little agreement that can be found between the elements of the orbits of all the comets that have been obferved, it appears clearly that they may be directed to carry their falutary influence to any part of the heavens. My hypothefis, however, as before obferved, does not lay me under any obligation to explain how the fun can fuftain the wafte of light, nor to shew that it will fuftain it for ever; and I should also remark that, as in the ana logy logy of generating cloulds I merely alJude to their production as owing to a decompofition of fome of the elaftic fluids of our atmosphere, that analogy, which firmly refts upon the fact, will not be lefs to my purpose to whatever cause thefe clouds may owe their origin. It is the fame with the lucid clouds, if I may fo call them, of the fun. They plainly exift, because we fee them; the manner of their being generated may remain an hypothefis; and mine, till a better can be propofed, may stand good; but, whether it does or not, the confequences 1 am going to draw from what has been faid will not be affected by it. Before I proceed, I fhall only point out, that according to the above theory, a dark spot in the fun is a place in its aumofphere which happens to be free from luminous decompofitions; and that faculæ are, on the contrary, more copious mixtures of fuch fluids as decompofe each other. The penumbra which attends the fpots, being generally depreffed more or lefs to about half way between the folid body of the fun and the upper part of thofe regions in which luminous decompofitions take place, must of course be fainter than other parts. No fpot favourable for taking measures having lately been on the fun, I can only judge, from former appearances, that the regions in which the luminous folar clouds are formed, adding thereto the elevation of the faculæ, cannot be less than 1843, nor much more than 2765 miles in depth. It is true that in our atmosphere the extent of the clouds is limited to a very narrow compass; but we ought rather to compare the folar ones to the luminous decompofitions which take place in Our aurora borealis, or luminous arches, which extend much farther than the cloudy regions. The density of the luminous folar clouds, though very great, may not be exceedingly more fo than that of our aurora borealis. For, if we confider what would be the brilliancy of a space two or three thousand miles deep, filled with such corrufcations as we fee now and then in our atmofphere, their apparant intenfity, when viewed at the distance of the fun, might not be much inferior to that of the lucid folar fluid. From the luminous atmosphere of the fun I proceed to its opaque body, which, by calculation from the power it exerts upon the planets, we know to be of great folidity; and from the phanomena of the dark spots, many of which, probably on account of their high fituations, have been repeatedly seen, and otherwife denote inequalities in their level, we furmife that its furface is deverfified with mountains and vallies. What has been faid enables us to come to fome very important conclufions, by remarking, that this way of confidering the fun and its atmosphere, removes the great diffimilarity we have hitherto been ufed to find between its condition and that of the rest of the great bodies of the folar fyftem, The fun, viewed in this light, appears to be nothing else than a very eminent, large, and lucid planet, evidently the first, or, in ftrictness of speaking, the only primary one of our fyftem; all others being truly fecondary to it. Its fimilarity to the other globes of the folar fyftem with regard to its folidity, its atmosphere, and its deverfified surface; the rotation upon its axis, and the fall of heavy bodies, leads us on to fuppofe that it is moft probably alfo inhabited, like the rest of the planets, by beings whofe organs are adapted to the peculiar circumftances of that vaft globe. Whatever fanciful poets might fay, in making the fun the abode of bleffed fpirits, or angry moralifts devise, in pointing it out as a fit place for the punishment of the wicked, it does not appear that they had any other foundation for their affertions than mere opinion and vague furmife; but now I think myfelf authorised, upon aftronomical principles, to propofe the fun as an inhabitable world, and am perfuaded that the foregoing obfervations, with the conclufions I have drawn from them, 4 0 2 are are fully fufficient to answer every objec- of an eafy, chemical combination with tion that may be made against it. its rays, their emiffion would be much impeded. It may, however, not be amifs to remove a certain difficulty, which arifes from the effect of the fun's rays upon our globe. The heat which is here, at the distance of 95 millions of miles, produced by thefe rays, is fo confiderable, that it may be objected, that the furface of the globe of the fun itself must be fcorched up beyond all conception. This may be very fubftantially anfwered by many proofs drawn from`natural philofophy, which fhew that heat is produced by the fun's rays only when they act upon a calorific medium; they are the cause of the production of heat, by uniting with the matter of fire, which is contained in the fubftances that are heated as the collifion of flint and ftel will inflame a magazine of gunpowder, by putting all the latent fire it contained into action. But an inftance or two of the manner in which the folar rays produce their effect, will bring this home to our most common experi ence. On the top of mountains of a fufficient height, at an altitude where clouds can very feldom reach, to fhelter them from the direct rays of the fun, we always find regions of ice and fnow. Now if the folar rays themselves conveyed all the heat we find on this globe, it ought to be hoteft where their courfe is leaft interrupted. Again, our aeronauts all confirm the coldnefs of the upper regions of the atmosphere; and fince, therefore, even on our earth the heat of any fituation depends upon the aptnefs of the medium to yield to the impreffion of the folar rays, we have only to admit, that on the fun itfelf, the elaftic fluids compofing it atmosphere, and the matter on its furface, are of fuch a nature as not to be capable of any exceffive affection from its own rays; and, indeed, this feems to be proved by the copious emiffion of them; for if the elaftic fluids of the atmosphere, or the matter contained on the furface of the fun, were of fuch a nature as to admit Another well known fact is, that the folar focus of the largeft lens, thrown into the air, will occafion no fenfible heat in the place where it has been kept for a confiderable time, although its power of exciting combuftion, when proper bodies are expofed, fhould be fufficient to fuse the most refractory subftances*. It will not be neceffary to mention other objections, as I can think of none that may be made, but what a proper confideration of the foregoing obfervations will eafily remove; fuch as may be urged from the diffimilarity between the luminous atmosphere of the fun and that of our globe will be touched' upon hereafter, when I confider the objections that may be affigned against the moon's being an inhabitable fatellite. I fhall now endeavour, by analogical reafonings, to fupport the ideas I have fuggefted concerning the conftruction and purposes of the fun; in order to which, it will be neceffary to begin with fuch arguments as the nature of the cafe will admit, to fhew that our moon is probably inhabited. This fatellite is of all the heavenly bodies the nearest, and therefore moft within the reach of our telescopes. Accordingly we find, by repeated infpection, that we can, with perfect confidence, give the following account of it. It is a fecondary planet, of a confiderable fize; the furface of which is diverfified, like that of the earth, by mountains and vallies. Its fituation, with refpect to the fun, is much like that of the earth; and, by a rotation on its axis, it enjoys an agreeable variety of feasons, and of day and night. *The fubject of light and heat has been very ably difcuffed by M. de Luc, in his excellent work, Idées fur la Météorologie, Tome Feu; and Tome II, part 3, chap. 6, section 2, I, part 2, chap. 2, fection 2, De la Nature du Des Rapports de la Lumière avec la Chaleur dans l'Atmosphère. To 1 To the moon, our globe will appear that our earth is inhabited, were to give To this it may be objected, that we perceive no large feas in the moon; that its atmosphere (the existence of which has even been doubted by many) is extremely rare, and unfit for the purpofes of animal life; that its climates, its feafons, and the length of its days, totally differ from ours; that without dente clouds (which the moon has not) there can be no rain; perhaps no rivers, no lakes. In thort, that, notwithflai ding the fimilarity which has been pointed out, there feems to be a decided dif. ference in the two planets we have compared. My answer to this will be, that that very difference which is now objected, will rather ftrengthen the force of my argument than leffen its value: we find, even upon our globe, that there is the moft ftriking difference in the fituation of the creatures that live upon it. While man walks upc n the ground, the birds fly in the air, and fishes fwin in water; we can certainly not object to the conveniencies afforded by the moon, if thofe that are to inhabit its regions are fitted to their conditions as well as we on this globe are to ours. An abfolute, or total fameness, fecms rather to denote imperfections, fuch as nature never expofes to our view; and, on this ac count, I believe the analogies that have been mentioned fully fufficient to eftablish the high probability of the moon's being inhabited like the earth. To proceed, we will now fuppofe an inhabitant of the moon, who has not properly confidered fuch analogical reafonings as might induce him to furmife Thefe confiderations ought to make the inhabitants of the planets wifer than we have fuppofed thofe of their fatellites to be. We furely ought not, like them, to fay "the fun (that immenfe globe, whofe body would much more than fill the whole orbit of the moon) is merely an attractive centre to us.' From experience we can affirm, that the performance of the moft falutary offices to inferior planets, is not inconfiftent with the dignity of fuperior purpofes; and, in confequence of fuch analogical reasonings, affifted by telescopic views, which plainly favour the fame opinion, we need not hesitate to admit that the fun is richly stored with inhabitants. This way of confidering the fun is of the utmolt importance in its confequences. That ftars are funs can hard ly ly admit of a doubt. Their immenfe very close together, that, notwithstand-` distance would perfectly exclude them ing the great diftance at which we from our view, if the light they fend may suppose the cluster itself to be, it us were not of the folar kind. Befides, will hardly be poffible to affign any fufthe analogy may be traced much farther. ficient mutual distance to the stars comThe fun turns on its axis. So does the pofing the cluster, to leave room for ftar Algol. So do the ftars 6 Lyra, à crowding in thofe planets, for whofe Cephei, Antinoi, o Ceti, and many fupport thefe ftars have been, or might more; most probably all. From what be, fuppofed to exist. It fhould feem, other caufe can we fo probably account therefore, highly probable that they exfor their periodical changes? Again, ift for themselves; and are, in fact, onour fun has fpots on its furface. So has ly very capital, lucid, primary planets, the ftar Algol; and fo have the ftars connected together in one great system already named; and probably every ftar of mutual fupport. in the heavens. On our fun thefe fpots are changeable. So they are on the ftar o Ceti, as evidently appears from the irregularity of its changeable luftre, which is often broken in upon by accidental changes, while the general pe-, riod continues unaltered. The fame little deviations have been observed in other periodical stars, and ought to be afcribed to the fame cause. But if the ftars are funs, and funs are inhabitable, we fee at once what an extenfive field for animation opens itself to our view. It is true that analogy may induce us to conclude, that fince stars appear to be funs, and funs, according to the common opinion, are bodies that ferve to enlighten, warm, and fuftain a fyf. tem of planets, we may have an idea of numberless globes that ferve for the habitation of living creatures. But if thefe funs themselves are primary planets, we may fee fome thoufands of them with our own eyes, and millions by the help of telescopes; when, at the fame time, the fame analogical reafoning ftill remains in full force, with regard to the planets which thefe funs may fupport. In this place I may, however, take notice that, from other confiderations, the idea of funs or ftars being merely the fupporters of fyftems of planets, is not abfolutely to be admitted as a general one. Among the great number of very compreffed clusters of stars, 1 have given in my catalogues, there are fome which open a different view of the heavens to us. The stars in them are fo As in this argument I do not proceed upon conjectures, but have actual obfervations in view, I fhall mention an inftance in the clusters, No 26, 28, and 35, VI. clafs, of my catalogue of nebulæ, and clufters of ftars. (See Phil. Tranf. Vol. LXXIX. Part II. page 251.) The stars in them are so crowded, that I cannot conjecture them to be at a greater apparent distance from each other than five feconds; even after a proper allowance for fuch stars, as on a fuppofition of a globular form of the clufter, will interfere with one another, has been made. Now, if we would leave as much room between each of these ftars as there is between the fun and Sirius, we must place these clusters 42,104 times as far from us as that star is from the fun. But, in order to bring down the luftre of Sirius to that of an equal ftar placed at fuch a distance, I ought to reduce the aperture of my twenty feet telescope to lefs than the two-and-twenty hundredth part of an inch; when certainly I could no longer expect to fee any star at all. The fame remark may be made, with regard to the number of very clofe double ftars, whose apparent diameters being alike, and not very fmall, do not indicate any very great mutual distance. From which, however, must be deducted all thofe where the different diftances may be compenfated by the real difference in their refpective magnitudes. To what has been faid may be added, that in fome parts of the milky way, |