to colour: Herschel I. even found the nucleus of the same comet (1811) pale ruddy, the envelope greenish or bluish green and a similar contrast was noted by Struve I. in Halley's comet in 1835, and by Winnecke in 1862. That the Sun induces in them a polar force superior to that of gravitationthe hypothesis, in the main, of Olbers-is most probable from the form of the envelope and tail, as if repelled alike from the nucleus and Sun: and that a certain portion of the rarer material is dissipated during the perihelion passage is evident from the very aspect of a tail such as that of 1858, whose restoration to the rapidly advancing nucleus is, to our apprehension, an impossibility. And in this, and in the destructive resistance which one comet (that of Encke) is known, and all may be presumed, to suffer, from the denser æther around the Sun, we find a striking indication that our system was not made to be eternal. The perfect balance of its construction might at first lead to another impression, and seem to countenance the old objection, that 'all things continue as they were from the beginning of the creation.' But here is evidence to the contrary—a slight but decisive symptom that—' they all shall wax old as doth a garment '—that 'they shall be changed,' A similar cause has probably been acting upon the comet of Biela; whose separation into two parts is one of the marvels of modern astronomy.† Single in all previous observed returns, (those of 1772, 1805, 1826, 1832,) in 1846 it became elongated, and then threw off a portion which increased till it rivalled and even for a short time surpassed its parent, each * This comes out well chemically. The 'Donati' was photographed : with Comet II., 1861, it was found impossible, even by De La Rue.

Liais at Olinda saw a second smaller and fainter nebulosity on several nights by the side of Comet I. 1860, previous to its disappearAstr. Nachr. 1248.

ance.

having at one period a starry nucleus and short tail, while they were connected by faint streams of light: and thus they continued in sight for more than three months, keeping a distance of something more than 150,000 miles, the companion being the first to vanish. When next seen by Secchi, in 1852, the distance was more than eight times greater, being 2TM in RA, and 30' in Declination, as though they were becoming independent bodies: their next favourable return (1866) was looked for with no common interest; but they were not seen, and probably will never again be seen by mortal eye. Nor has the larger comet of De-Vico, discovered by him in 1844, with an apparent period of 5 years, ever shewn itself again -it has

'wandered away alone,

No man knows whither.'

The identity of the orbits of two comets (II, 1862; and I, 1866, believed to be the same as that of 1366) with the paths of the meteor-showers in August and November is one of the most remarkable of modern discoveries, for which Schiaparelli has recently received the Gold Medal of the Royal Astronomical Society. It is however needless, in a treatise like the present, to make more than a passing allusion to a subject of this nature.

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PART III.

THE STARRY HEAVENS.

Lift up your eyes on high, and behold Who hath created these things, that bringeth out their host by number: He calleth them all by names by the greatness of His might, for that He is strong in power; not one faileth. ISAIAH, xl. 26.

IF the Solar System had comprised in itself the whole material creation, it would alone have abundantly sufficed to declare the glory of GoD, and in our brief review of its greatness and its wonder we have seen enough to awaken the most impressive thoughts of His power and wisdom. But that system is but as a single drop in the ocean. What boundary may be set to creation we know not, but we can trace it sufficiently to perceive that, as far as our senses are concerned, it cannot be distinguished from absolute infinity: and in leaving our Sun and his attendants in the background, we are only approaching more amazing regions, and fresh scenes will open upon us of inexpressible and awful grandeur. We are now to contemplate not one Sun, but thousands and myriads :-not a planetary system of subordinate globes, but aggregations of Suns;-pairs, groups, galaxies of Suns-'the host of heaven,'-all independent in unborrowed splendour, yet many evidently, and all by clear implication, bound together by the same universal law which keeps the pebble in its place upon the surface of the earth, and guides the falling drop of the

shower, or the mist of the cataract. Many of these Suns may probably be smaller or dimmer than our own, yet others unquestionably far surpass his splendour; while as to distance, their remoteness is so inconceivable that light itself, flying with a speed which would encircle the Earth nearly 8 times in one second, only shews them to us as they formerly were, -some, years, others, centuries,-others perhaps whole ages back, even in the first dawn of creation. Here is indeed a field where enterprise cannot be thrown away, nor perseverance fail of its reward.

We must, however, remember that, though they are Suns which we are contemplating, and though the mere aspect of some of them in a large telescope well bears out the assertion,* yet a great proportion are diminished by distance to the minutest points of light, and can only be distinctly seen under favourable circumstances. We cannot therefore expect uniform success; in fact, the more delicate objects of stellar astronomy are not only among the severest tests of the telescope and the eye, but are peculiarly liable to be affected by atmospheric indistinctness, and require the most propitious skies. The cautions suggested in Part I. will be especially applicable here.

An original investigation of all the objects worthy of notice, even in a popular sense, in the starry heavens, would have been the attempt of a lifetime, rather than of such occasional hours of leisure as I could command: an unverified selection, on paper, from a standard list formed with a very different design, would have been an easy, but not a satisfactory task:

*The approach of Sirius to the field of H.'s 40 f. reflector is said to have been ushered in by a dawning light, and its actual entrance to have been almost intolerable to the eye: yet the 4 f. mirror was far from good. What must be the blaze of this star in the Earl of Rosse's telescope, with a speculum of 6 f., of much higher reflective power!

a middle course has therefore been preferred. All such of the 850 Double Stars and Nebula of Vice-Admiral Smyth's Bedford Catalogue as my 37 in. of aperture could be expected to reach, were examined in succession, and those only retained for our purpose which seemed to possess sufficient general as well as scientific interest, and might serve as specimens of the universal profusion: and as in such a review a number of other objects, beautiful to the popular eye, though unimportant perhaps to the professed astronomer, presented themselves unsought, many of these have been added to the list, as well as many from Struve's 'Mensuræ Micrometricæ,' of which those examined by me are distinguished by brackets [ ]; the rest, included in parentheses (), are selected without personal observation, chiefly from Struve, either as obviously suitable for our purpose, or as instances of the many hundred similar objects in that great work. To these, the attentive student will be continually gathering fresh groups and combinations, especially from the crowded fields of the Galaxy;-a very little experience will convince him of the unspeakable richness of the firmament.

From a pressure of other employments, the interval since the first appearance of this little work has not added much original matter to the following catalogue. But it is to be hoped that some zealous lover of this great display of the glory of the Creator will carry out the author's idea, and study the whole visible heavens from what might be termed a picturesque point of view. This would involve nothing more than a sufficiency of optical power, of leisure, and of patience bringing with it its abundant reward. By a suitably arranged plan, every part of the sky might be swept over in succession, and the principal instances of intensity of colour, or elegance