THE SUN AS A DWELLING-PLACE.

IN the physics of the universe, as in the customs of human societies, there are many serious qualifications to the advan- tages of a central situation. Sir William Armstrong suggested,

in his inaugural address last week to the British Association, that that curiously mottled appearance of the sun's bright atmosphere when seen through a telescope, which has given rise to Mr. Nasmyth's expression about the solar "willow-leaves," might be due to " organized " forms of matter ; and that the constant supply of heat which warms the whole solar system may, as previous astronomers have suggested, be due to the constant con- cussion of falling bodies rushing into the centre of our system, and heating it just as his own cannon-balls or shells heat the great targets at Shoeburyness. Both these suggestions are, of course, mere guesses, though the latter, at least, is as probable as any other mere conjecture concerning the source of the solar heat,; but both of them suggest so many marvels and inconveniences which would attend its possible inhabitants, if it could be the habitation of beings in any way resembling the inhabitants of this earth, that if astronomers were to acquiesce in them, or, at least, in the latter of them, the sun would probably be given up as rapidly as the moon to that desolating theory of Dr. lirhewelfs, which refuses to give rational animals a foothold anywhere in the universe except upon our little planet. Certainly, one would not choose for a dwelling-place a sphere, however majestic, eternally bombarded from all parts of the celestial spaces,—a world into which minute planets, that had been travelling from infinite dis- tances with a constantly accelerating speed, should be constantly crashing home, where the annexation of a comet would be an every-day event. Sebastopol or Vicksburg under siege would be a sort of heaven to such a life as that, besides that, they at least had the satisfaction of returning the fire, which would be impos- sible for the sun, seeing that the force which would keep up the bombardment would be of no alien origin, but inseparable from its own existence. The big salamanders, 100,000 miles in area, which Sir W. Armstrong pictured as floating in the solar atmosphere, and this heavy celestial artillery, are alike matters of conjecture ; but of the sun as a dwelling-place for embodied crea- tures we can form a few notions based on more trustworthy facts. Indeed, the elder Herschel, who was one of the earliest theorists about the sun's spots, always held that the sun might be inhabited ; —that its solid nucleus, that is, need not be so hot as to prevent the existence of beings organized more or leas as we are. It is, at least, worth while to consider what sorts and degrees of differ- ence such a life, if it be possible, would imply, even without an atmosphere of gigantic salamanders, and a converging fire of innumerable meteors and planetoids, or a lashing by cometary tails a few millions of miles in length.

In the first place, there is, no doubt, room enough for a very considerable immigration there, as the surface of the sun would accommodate in mere extent the population of 12,000 earths. In other words, if the earth had been fully peopled during 12,000 generations, and all its population transferred to the sun, the sun would only then become fully peopled, supposing its surface to be in the same proportion susceptible of cultivation. Unfortunately, however, the muscular power needed for walking on the sun would have to be twenty-eight times as great, for a man of the same size, as the muscular power needed for walking on the earth. The sun is very much less dense than the earth,—not much, indeed, above the density of water,—but its enormous size increases the gravi- tation there to twenty-eight times its power on earth. Every man, therefore, suddenly transferred to the surface of the sun,—if he could live there at all,—would appear to himself to have an accumulation of twenty-seven other men upon his back—a weight under which it is needless to observe that no human muscles could stagger. However, swimming upon such a surface, in any fluid as light as water (and the bulk of the sun appears to be made up of fluid at least as light as this) would be far easier than it is here ; for all weights being multiplied by about twenty-eight, the difference between the weight of the water dis- placed and of the human body, —which measures the supporting force,—would also be multiplied by twenty-eight; and just in pro- portion, therefore, as the difficulty of walking is increased there, that of swimming (in such a fluid as our water) would be dimi- nished.

But these differences are trifling compared with the differences arising from the central position of the sun. To inhabitants of that globe there would be no such phenomena as day and night, but a perpetual and uniform blaze, like the light with which the roofs of the Houses of Parliament are nightly lighted up, though infinitely intense, would be always blazing above that semi-transparent cloudy screen which Sir William Herschel thought might temper the light and of the heat solar world. Most of our best astronomers believe that the sun has three strata of atmosphere. The highest stratum is a genuine atmosphere like our own, the existence of which is betrayed by the red beads of the solar eclipse, due to the same atmospheric cause as the red light of sunset, and also by the comparative paleness of the edges of the solar disc (whose obliquer light would travel to us through much more of this atmosphere than the light from the centre).

The middle is the phosphorescent atmosphere in which the light (and perhaps heat) of the sun is situated. The lowest one, again, is an atmosphere full of thick cloud, which is seen by us only when one of the cavities opens in the outer atmosphere which we call " spots " on the sun. At all events, it is quite certain that the illuminating power of the sun is quite external to its principal mass,—for it is proved that the spots are cavities in the illumi- nating surface showing a much darker world beneath. Sir David Brewster, indeed, believes that though the light of the sun is derived from the higher strata of its atmosphere, its heat comes from the body of the sun itself, and urges, we believe, in confirma- tion, that those years are hottest when there are most of these dark spots on the sun, instead of when there are fewest. This, however, is an exceedingly doubtful fact, and probably there are as yet no data for deciding it either way. In the mean time, it is natural to suppose that the light and heat are derived from the same source, and that since we have at times glimpses into the recesses of a darker sphere, that darker sphere would also be a cooler sphere than we usually connect with our visible sun. Indeed, if inhabitable at all, it would need to be. The temperature of the sun's heated surface is calculated to be seven times as hot as the hottest known blast fur- nace. "It would require the combustion of more than 130,0001bs., or nearly sixty tons of coal per hour, on each square foot of the sun's surface, to produce a heat equal to that radiated from the solar orb." We can easily imagine how very thick a stratum of cloud and air it would need to protect the solar inhabitants, if such there are, from a heat and light so intense and so constant, where there is no periodic night to lower the temperature and rest the eye after the heat and glare of the day. This heat and light would have to shine through a most effectively protecting roof of cloud to be in any way consistent with human or quasi-human organisms. At the same time, it may be reasonably argued that the heat we picture to ourselves must at some point or other be tempered, if only towards the very centre of the solar globe, since it would otherwise reduce the whole globe to gas, while the sun has, in fact, an average density greater than water ; and this being so, there must be a limit at which this enormous heat is reduced—though, of course, the nearest approach to solidity might be seas of molten iron. Still the probability of some deep cloudy stratum of atmosphere enveloping a cooler world seems considerable.

But even if this be so, the vast difference between the physi- cal situation of the Sunites and that of our race would scarcely be much diminished. With a sufficiently thick sea of cloud be- tween them and the intolerable light and heat, they might manage to exist, like the fabled mermen who, living on the ocean floor, saw sunlight only through the unfathomable depths of the sea. But then, though living in the centre of our aye- tern, they could never know that there was a system at all beyond- ' this centre. They could not even know that their own sun revolves in about twenty-five and a half of our days on its own axis.

For no celestial phenomena at all could be accessible to them. The constant and uniform light would shut them in far more effectually than any darkness; and the cloud which would be essential to soften that constant and uniform light would be a second screen. We could never know that our own earth revolved on its axis if a blaze stronger than the strongest noon always shut out the night. And the solar inhabitants certainly would be far more effectually cut off from astronomy, both by their light and by the internal screen which would interrupt the light, than by any darkness. The planet Neptune would have a better chance of good astronomers than the sun. The absence of anything like night and dew, and of all the consequent periodic changes in the vege- table and animal world, would certainly revolutionize the whole character of the agriculture, and natural history. Sleep might perhaps exist without night, but both plants and animals must have a different structure in order to secure it. Then, too, there could be no change of the seasons, and even mountains instead of rising into a colder zone would probably rise into a hotter. The

equator of the sun, indeed, would, Sir John Herschel thinks, be hotter than its poles, owing to the greater accumulation of the third or external atmosphere around its central belt (just as water set spinning gets heaped up round the middle and flattened at both ends), so keeping the heat in more at the equator than at the poles. And to this Sir John Herschel ascribes the spots which appear and disappear in two belts—corresponding to the belts of our trade-winds—on the sun's surface. He thinks these

are apertures caused by the external atmosphere breaking through the fiery atmosphere, in eddies like water-spouts,—for reasons analogous to those which restrict circular whirlwinds and water-

spouts even on our earth to the regions of the trade-winds. The notion is confirmed by the fact that these spots on the sun have been observed to spin round on some axis of their own, before

closing in, just as if they were of the nature of monstrous

eddies But even these tornadoes, 'which in certain latitudes of the sun, perhaps break through as far as the lower envelope of clowl, can scarcely open to the Suuites a tunnel through which they could see the stars,—for if it really penetrate the inner veil of cloud, it would probably carry fire and destruction with it.

In a word, the Suuites must in all probability pay for their central position by being quite ignorant of it, and of thousands of other phenomena to which the alternation of night and day, summer and winter, are absolutely essential. "A glorious privacy of light" is theirs, if glorious it be. Illumined by a mighty spheri- cal chandelier, rather than a sun, which they can never turn down, which roofs in their universe and roofs out the infinitude of worlds, they might, if they had any suspicion of the truth, say, with the poet :—

" Oh! who could tell such darkness lay concealed Beneath thy beams, oh Sun ? Or who could find, When fly, and leaf, and insect lay revealed, That to such countless orbs thou mad'st us blind ?"

—nay, to more than countless worlds outside them,—for to the varieties of torrid and frigid zone, of spring-time and harvest, of morning and evening,—probably even of work and rest,—and to a large proportion of that which makes countless worlds of thought and reflection within, the same dreadful uniformity of splendour would equally blind them. Then, too, shadow would be as rare there as it is frequent here,—for the light always flowing equally from North, South, East, and West, it would be only at a door, window, or a cavern's mouth, where the other quarters were protected from the light, that shadow would be seen. Imagine all the intellectual fruits of such varieties struck out of our literature and history, and what would the human mind be ? The sun may be a dwelling-place for beings whose inner world has begun to develop itself regularly without the stimulus of outward variety and change, but scarcely for any natures less advanced. That which knows "no variableness nor shadow

of turning" must either be God or nothing,—the highest life or the most absolute nonentity. If we did live there, we should

soon, perhaps, prefer being bombarded by fragments of planet rushing sunwards, even at the risk of annihilation, to the hot changeless uniformity of such an orb. We almost wonder no one has suggested the sun as the physical locality of the place of tor- ture. That it would make evil the root and centre of our system, would only be an additional recommendation to a very popular form of modern theology.