their immediate superior," as any other arrangement would be utterly incompatible with the conditions necessary for the existence of their inhabitants. In opposition to this fine observation, our author asserts that Sir John Herschel "in making this provision, has overlooked that it may not be possible to keep them (the planets) in permanent orbits so near to the selected centre; their sun may be a vast sphere of luminous vapour; and the planets plunged into this atmosphere may, instead of describing regular orbits, plough their way in spiral paths through the nebulous abyss to its central nucleus !"

Having obtained "but little promise of inhabitants from clustered and double stars," our author "turns his attention to the single stars as the most hopeful," and in asking "what is the kind of proof which we have" of their being "the centres of planetary systems," he replies, that "the only proof resides in the assumption that these stars are like the sun;-resemble him in their quality and nature." He then proceeds to shew that the stars are not like the sun, but by statements so little precise and so difficult to meet by direct argument, that we may reply to them in the most convincing manner by shewing that the fixed stars are like our sun.

1. The sun and stars shine by direct and not by borrowed light.

2. The spectra of the sun and stars have numbers of definite dark lines which do not exist in artificial light. Some of these lines have the same place in each of the spectra."

3. The stars of alpha centauri and 61 cygni have the same law of gravity as our sun.

4. Some stars have a motion round their axis as indicated by the variable light of some, and the periodical disappearance of others.

5. Several stars are of variable brightness. The brightness of our sun varies to a small extent, according to the number and size of the spots on its surface, and to other systems its light must be still more variable when it is obscured by the semiopaque and widely spread tails of comets during their passage through our system.

In opposition to these marked points of resemblance, the author brings forward the following points of dissimilarity :

1. "No small number of the stars undergo changes of brightness, not periodical but progressive."-The sun of course does not.

Our author erroneously states that "there is no obvious distinction between the original light of the stars, and the reflected light of the planets." The difference is such that we can tell which is star and which is planet by the character of their spectra.

Similarity of the Fixed Stars to our Sun.

31

2. Sirius has changed from red to white. Eta Argus from yellow to red.-The sun is unchangedly white.*

3. Some stars have perished-the Lost Pleiad for examplethe sun has not perished.

4. The star of 1572 existed only seventeen months, and that of 1604 a still shorter time.-The birth and death of the sun have not yet been recorded.

5. Stars really periodical are proved not to be like but unlike

our sun.

Admitting, as we may well do, for the sake of argument, all these points of dissimilarity, and making to him a present of double the number, let us endeavour to convey to our less scientific readers a distinct idea of the nature and force of his reasonings.

London, we shall suppose, is illuminated with one large electric light from the top of St. Paul's, and an aeronaut from that city while travelling in his balloon over France, sees a thousand lights of exactly the same colour and character as that of his native city. He never doubts that these are electric lights intended to illuminate a number of villages, or the different parts of a city; but upon a more attentive study of the lights, he finds one or two red and blue, one flickering, one going out, one appearing where he saw none before,-would these different conditions of ten out of a thousand of the electric lights induce him to change his opinion that the electric lights which he had been studying were different from the large electric light on St. Paul's, and that all the thousand were intended to illuminate the locality on which they are placed? If our sun is unlike a few coloured, variable, and temporary stars, he is precisely the magnified image of all the million that stud the heavens.

Our readers must have already seen that our author's opinions are degrading to astronomy, and subversive of its grandest truths. The nebula are reduced to gas or to comets' tails-the stars dwindle into luminous vapour that may fill the whole of the earth's annual orbit, and the binary systems sustained by the law of gravity are unfit for inhabitants, because their planets would be whirled in spirals to the central nucleus. But the tendency of his opinions to bring astronomical truths into contempt is peculiarly shewn in the cursory and unwilling reference which he makes to the "proper motion of the stars." We have already stated it as a strong argument for a plurality of worlds, that the sun and the whole planetary system is advancing in space, and revolving round some distant and yet invisible centre. This grand cosmical truth, the grandest in astronomy, and forming the only

* See this Journal, vol. vi. pp. 235-238.

link which peculiarly connects us with the sidereal universe, has been deduced by the most distinguished astronomers of all nations, by a rigorous induction, from the proper motions of the fixed stars. Every living astronomer has adopted the great truth, but it has been contemptuously rejected by our author because it bears so strongly against his views. He enumerates it among the conjectures of astronomers, "which he need not notice, as they do not appear to have any bearing on our subject. Such," he continues, "are the proper motions of the stars, and the explanation which has been suggested by some of them; that they arise from the stars revolving round other stars which are dark and therefore invisible.* Such again is the attempt to shew that the sun carrying with it the whole solar system, is in motion; and the further attempt to shew the direction of this motion; and again the hypothesis that the sun itself revolves round some distant body in space."

Having shunned the consideration of truths like these, and failed entirely in bringing forward a single scientific argument against the doctrine of a plurality of worlds, he next addresses himself to the plainest capacities, by one of those illustrations of which he is a great master, but which, when well examined, is found to be a double tool with its sharpest edge turned against its author. In referring to a simple illustration of Fontenelle's,t which he considers as not fair, he gives the following modification of it as "representing his own argument more fairly."

"Let it be supposed," he says, "that we inhabit an island, from which innumerable other islands are visible, but the art of navigation being quite unknown, we are ignorant whether any of them are inhabited. In some of these islands are seen masses more or less resembling churches, and some of our neighbours assert that these are churches; that churches must be surrounded by houses, and that houses must have inhabitants; others hold that the seeming churches are only peculiar forms of rocks: in this state of the debate everything depends upon the degree of resemblance to churches which the forms exhibit. But suppose that telescopes are invented and employed with diligence on the questionable shapes. In a long course of careful and skilful examination, no house is seen, and the rocks do not at all become more like churches, rather the contrary. So far, it would seem, the probability of inhabitants in the islands is lessened. But there are other reasons brought into view. Our island is a long extinct volcano, with a tranquil and fertile soil, but the other islands

* Our Author here alludes to the fine speculation of the illustrious Bessel, that single stars such as Sirius and Procyon must be parts of smaller systems, and, therefore, must revolve round non-luminous and centrical bodies not far from the star itself. See this Journal, vol. ii. p. 197; vol. v. p. 231; and vol. vi. p. 238. + Eutres, tom. ii. p. 47. Second Soir. Edit. 1758.

Erroneous Illustration used by the Author.

33

are apparently somewhat different. Some of them are active volcanoes, the volcanic operations covering, so far as we can discern, the whole island; others undergo changes, such as weather or earthquakes may produce; but in none of them can we discover such changes as shew the hand of man. For these islands, it would seem, the probability of inhabitants is further lessened. And so long as we have no better evidence than these for forming a judgment, it would surely be accounted rash to assert that the islands in general are inhabited; and unreasonable to blame those who deny or doubt it. Nor would such blame be justified by adducing theological or a priori arguments; as that the analogy of islands with islands makes the assumption allowable; or that it is inconsistent with the plan of the Creator of islands to leave them uninhabited. For we know that many islands are or were long uninhabited. And if ours were an island occupied by a numerous, well-governed, moral, and religious race, of which the history was known, and of which the relation to the Creator was connected with its history; the assumption of a history, more or less similar to ours, for the inhabitants of the other islands, whose existence was utterly unproved, would, probably, be generally deemed a fitter field for the romance writer than for the philosopher. It could not, at best, rise above the region of vague conjecture."-Pp. 158, 159.

When we admit that our author has proved by his illustration that there is no reasonable ground for believing that any one of his innumerable islands is inhabited, we pass the severest censure upon the fairness with which he professes to illustrate his views. He has had recourse to a clever illustration, not for the purpose of instructing, but of misleading his readers. In support of this allegation we may state, in the first place, that no illustration is fair, or can be successful, unless it relates to separate and independent works of God, from the state of one of which we draw inferences by analogy, relative to the state of the rest. The parallel between islands and planets is unjust, because there ought to have been certain properties or conditions of the peopled island necessary for its inhabitants, which should have been possessed by the other islands. The inhabited island, too, should have been made as insignificant in reference to the rest, as the Earth is to Jupiter, Saturn, and other planets. The observation of volcanoes, active and extinct, and of rocks like churches, as made by the telescope, has no parallel in the analogy of the planets. The argument from analogy, indeed, in reference to the Earth, with its oblate form, its moon, its day and night, and seasons, is so simple and clear that no illustration can make it clearer. But, however this may be, every attempted illustration should be founded on the axiomatic truth admitted by every philosopher, and easily appreciated by the most ordinary minds, that, in the works of God, VOL. XXI. NO. XLI.

C

as studied upon our own globe, whether they be the structures of man and animals, or of plants and inorganic bodies, economy of power is universally displayed. Nothing is made in vain,-nothing by a complex process that could be made by a simple one; and it has often been remarked that the infinite wisdom of the Creator is more strikingly displayed in the economy than in the manifestation of power. It is certainly possible that the Almighty Architect of the universe may have had other purposes in view, incomprehensible to us, than that of supporting animal and intellectual life on the magnificent spheres of matter which fill the immensity of space; but we, the inhabitants of one of the least of these globes, which has for millions of years been in possession of animal, if not of intellectual life, and that obviously with the design of preparing it for man,—we who must be guided by our knowledge, however limited, never can comprehend, (and never will believe it possible,) that planets the same as our own, have not been destined for the same rational and noble purpose,-destined, doubtless, for an intellectual race, and destined probably for a previous and lengthened occupation by the lower animals, in order that beings "made after God's image and likeness," may study on the tombstones of the past the miraculous processes of growth and decay,—of destruction and renovation, by which he has provided for his children so noble an inheritance.*

In the ninth chapter, upon the Planets, our author begins with disqualifying Neptune from the privilege of being inhabited

* Our author concludes his chapter on the fixed stars by a speculation, in a note, so calculated to throw contempt upon Astronomy, and to ridicule the very subject of his own work, that we cannot pass it by without grave reproof. He had previously made statements indicating "that our seeing a star was evidence, not that it exists now, but that it existed, it may be many thousands of years ago," and as he thinks that such a statement "may seem to throw doubt upon the reasonings he has employed," he concludes his note with the following observations :"It may be said that a star which was a mere chaos, when the light by which we see it, set out from it, may, in the thousands of years which have since elapsed, have grown into an orderly world. To which bare possibility we may oppose another supposition, at least equally possible, that the distant stars were sparks struck off in the formation of the solar system, which are really long since extinct, and survive in appearance only by the light which they at first emitted!" Without laying any stress on the circumstance that the bare possibility here referred to, that a star may have passed from the state of chaos into that of an orderly world, is the actual fact with regard to our own Earth, we ask our reader's attention to the equally possible supposition of our author, that the distant stars may be sparks struck off the planets of our system. A spark in our system, how struck off we cannot tell, unless by Vulcan when moulding the planets upon his anvil, wending its way out of the spheres of attraction of the planets, passing through the infinitely wide void between Neptune and the distant stars, and fixing itself in space, is a supposition from which we may fairly estimate the value of our author's other speculations. Sidereal Astronomy is, then, the Study of Sparks, struck off in the formation of the Solar system!