revolve around them; for the Creator and Governor of the universe must be considered, in all his arrangements, as acting in perfect consistency with those perfections of his nature with which he is eternally and essentially invested. But to suppose the innumerable host of stars to be only so many vast insulated globes, hung up to irradiate the void spaces of infinitude, would be repugnant to all the conceptions which reason and revelation lead us to form of a Being of infinite perfection. If, then, the fixed stars are the centres of light and influence to surrounding worlds, how immense must that empire be over which the moral government of the Almighty extends! how expansive the range, and how diversified the order of planetary systems! how numerous, beyond calculation, the worlds which incessantly roll throughout the immensity of space! What countless legions of intellectual beings of every rank and capacity must crowd the boundless dominions of the King eternal, immortal, and invisible! and how glorious and incomprehensible must He be whose word caused this vast fabric to start into existence, and who superintends every moment the immensity of beings with which it is replenished! In attempting to grasp such scenes the human mind is bewildered and overwhelmed, and can only exclaim, "GREAT AND MARVELLOUS ARE THY WORKS, LORD GOD ALMIGHTY!"

"Seest thou those orbs that numerous roll above?
Those lamps that nightly greet thy visual powers
Are each a bright capacious sun like ours.
The telescopic tube will still descry
Myriads behind that 'scape the naked eye,
And farther on a new discovery trace

Through the deep regions of encompassed space.
If each bright star so many suns are found,
With planetary systems circled round,
What vast infinitude of worlds may grace,
What beings people the stupendous space?
Whatever race possess the ethereal plain,

What orbs they people, or what ranks maintain?
Though the deep secret Heaven conceal below,
One truth of universal scope we know:
Our nobler part, the same ethereal mind,
Relates our earth to all their reasoning kind,
One Deity, one sole creating cause,

Qur active cares and joint devotion draws."

CHAPTER XV.

ON UNKNOWN CELESTIAL BODIES-ON METEORIC PHENOMENA AND ON SHOOTING STARS.

We are not to imagine that we have yet discovered the greater part of the bodies which exist in those spaces whose range lies within the reach of our telescopes. All the discoveries which have hitherto been made in the heavens have been owing to the light emitted by very distant orbs having been concentrated on the eye by the magnifying and space-penetrating power of the telescope; but it is not improbable that there are numerous bodies within the circuit of the visible heavens which send forth no rays of light susceptible of being refracted or reflected to the eye by our finest instruments. Some of the largest bodies in the universe may either be opaque globes, or so slightly illuminated that no traces of their existence can ever be perceived from the region we now occupy. The greater part, if not the whole, of the orbs which have been descried in the firmament, with the exception of the planets and comets of our system, are globes which shine with their own inherent lustre, without which their existence would have been to us for ever unknown. We are not warranted to call in question the existence of any class of bodies merely because our limited organs of perception and our situation in the universe prevent us from perceiving them. We have never yet beheld the planets which doubtless circulate around other suns, although there can be no question that such bodies really exist; and there may be opaque globes of a size incomparably larger than either planets or suns, which may serve as the centres of certain systems, or for some other important purposes to us unknown; for all that we have yet explored of the distant regions of creation is but the mere outskirts of that boundless empire which stretches out on every hand towards infinity. It is not unreasonable to believe that the number of magnificent bodies imperceptible to our organs of vision may far exceed all that we have hitherto discovered either by the naked eye or the telescope, even within the compass of that region which lies open to human inspection.

It has been remarked by La Place, that "a luminous star of the same density as the earth, and whose diameter should be two hundred and fifty times larger than that of the sun, would not, in consequence of its attraction, allow any of its rays to arrive at us." "A star which, without being of this magnitude, should yet considerably surpass the sun, would perceptibly weaken the velocity of its light, and thus augment the extent of its aberration." It is therefore possible that the largest luminous bodies in the universe, if their internal structure be composed of dense materials, would be invisible to us, in consequence of their great attractive power preventing their light from reaching the system to which we belong. In Chapter XII. I have given a brief view of the ideas entertained by Lambert respecting the arrangement of the universe into distinct systems of stars, which have a more immediate connexion with one another in consequence of the law of mutual gravitation, and whose views have been partly confirmed by the discoveries of Herschel. This illustrious mathematician and astronomer endeavours to prove, by an induction of facts and reasonings, that, in order to the stability of those systems, it is necessary, on the principles of universal gravitation, that there be a large central body around which all the individuals which compose the system revolve. There is no necessity that such a central body should possess original or underived light. The fixed stars do not stand in need of it; and as for itself, if it require illumination, it will receive it from the suns that are more immediately adjacent. As to the magnitude of such a centre, Lambert estimates that the central body of the system to which we belong must have a diameter at least equal to the whole circumference of the orbit of Saturn. "The magnitude of those bodies," he says, "ought not to alarm us; for, in the first place, we have nothing to do with their bulk, but with their density or quantity of matter by which the law of gravitation is regulated. We have no idea of the density of matter that is not porous; perhaps gold, the most dense of terrestrial substances, would be found a mere sponge compared with such a central body. Besides, nothing is great or small in immensity; and since on the wing of light we can traverse the vast regions of the heavens, matter and volumes ought no longer to excite our astonishment. Beginning with the satellites, even suns are but bodies of the first magnitude; the centres of the fixed

stars, of the fourth; those of groups of systems, of the fifth, and so of the rest.

Lambert supposes that, since such bodies must be of an enormous bulk, and illuminated besides by one or more fixed stars, it might be possible to perceive the one which belongs to our own system, either in whole or in part, with the help of the telescope; that its apparent diameter may be very considerable; that, however weak its reflected light, it may not be enfeebled to such a degree as to be rendered imperceptible; that, being enlightened by one or more suns, it ought to present phases analogous to those of the moon; that such a central body ought to extend its influence even to the extremities of its system, and, consequently, ought to appear under a sensible diameter, or at least be visible by the telescope; and that, as the attractive force of a body decreases as the square of the sine of its apparent semi-diameter, so this apparent semi-diameter cannot be invisible in any place to which its attractive force and its sphere of activity extend. Without sanctioning all the opinions which this ingenious mathematician has thrown out on this point, we may admit that the subject is worthy of special attention, and might be kept in view when we are exploring the heavens with our best telescopes. What if some of the planetary nebulæ be bodies of a nature similar to those to which we have now alluded?

If opaque globes of a prodigious size exist throughout the regions of the firmament, as there is reason to believe, they would afford us a clew for unravelling certain phenomena which have hitherto remained in some degree inexplicable. Stars have appeared all at once, and, after having shone for a year or more with a brilliant light, have gradually disappeared. Certain stars are found to pass through regular variations of lustre, and for a certain period entirely disappear; but, after a lapse of a certain number of months or days, reappear and resume their former brightness. On the supposition that opaque bodies exist nearly in the direction of such stars, some of these phenomena would admit of an easy explanation. Their appearing and disappearing might be nothing more than an occultation or an eclipse, caused by the interposition of the opaque globe between our eye and the star. This would, indeed, suppose motion to exist either in the opaque body, or in the star, or in the eye of the observer; and perhaps the annual motion of the earth, or the motion of the sun in absolute

space, might contribute, in a certain degree, to produce the effect. Motion of some kind or other must necessarily be supposed, in order to account for the phenomena of variable stars, whatever hypothesis we may adopt for their explanation; but, as nothing decisive can be stated on this subject, in the mean time I shall proceed to the consideration of some meteoric phenomena which are now supposed to have a connexion with certain moving bodies in the heavens.

Meteoric Phenomena and Shooting Stars,

In my volume entitled “Celestial Scenery," when describing the small planets Vesta, Juno, Ceres, and Pallas, I have given a detail of certain facts respecting the fall of large masses of solid matter from the higher regions of the atmosphere, usually denominated meteoric stones, which, there is every reason to believe, descend from regions at a considerable distance, and even beyond the sphere of the moon. Such phenomena seem to indicate the probability that certain opaque bodies of different dimensions are revolving through space in certain regions within the limits of our system. "Nor is this," says Mrs. Somerville, "an unwarranted presumption; many such do come within the sphere of the earth's attraction, are ignited by the velocity with which they pass through the atmosphere, and are precipitated with great violence upon the earth. The fall of meteoric stones is much more frequent than is generally believed. Hardly a year passes without some instances occurring; and if it be considered that only a small part of the earth is inhabited, it may be presumed that numbers fall in the ocean, or on the uninhabited part of the land, unseen by man. They are sometimes of great magnitude; the volume of several has exceeded that of a body of seventy miles in diameter. One which passed within twenty-five miles of us was estimated to weigh about 600,000 tons, and to move with a velocity of about twenty miles in a second; a fragment of it alone reached the earth. The obliquity of the descent of meteorites, the peculiar substances they are composed of, and the explosion accompanying their fall, show that they are foreign to our system."

But, without resuming the consideration of this particular phenomenon, there is another which of late years has excited