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behold, in one point of view, within a space little more than that of the one fifth of the apparent size of the moon, nearly a hundred resplendent suns emitting their effulgence from regions immeasurably distant, and arranged in beautiful symmetry and order; a scene of creating power surpassing in grandeur ten thousand worlds such as ours, and in which our whole planetary system would appear only as the smallest twinkling star. Such telescopic views of the nocturnal heavens have a tendency to expand the capacity of the soul, to inspire it with magnificent conceptions, and to raise its affections above the low ambition and paltry concerns of this transitory scene to the distant and more magnificent scenes of the Divine empire. To the devout and contemplative philosopher the following lines of the poet may be applied:

"Not to this evanescent speck of earth

Poorly confined-the radiant tracks on high
Are his exalted range; intent to gaze
Creation through, and from that full complex
Of never-ending wonders to conceive

Of the sole Being right, who spoke the word,

And nature moved complete."-THOMSON'S Summer.

Sir W. Herschel makes a distinction between groups and clusters of stars. A group is a collection of stars closely and almost equally compressed, and of any figure or outline. There is no particular condensation of the stars to indicate the existence of a central force, and the groups are sufficiently separated from neighbouring stars to show that they form peculiar systems of their own. According to this definition, the congeries of stars I have pointed out above are to be considered as belonging to the class of groups. Clusters of stars differ from groups in their beautiful and artificial arrangement. Their form is generally round, and their condensation is such as to produce a mottled lustre somewhat resembling a nucleus. The whole appearance of a cluster indicates the existence of a central force, residing either in a central body or in the centre of gravity of the whole system. The stars of which it is composed appear more and more accumulated towards the

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tails; but when these objects are examined with telescopes of great power, "they are then," as Sir J. Herschel remarks, "for the most part, perceived to consist entirely of stars crowded together so as to occupy almost a definite outline, and to run up to a blaze of light in the centre, where their condensation is usually the greatest." Many of them, indeed, are of an exactly round figure, and convey the complete idea of a globular space filled full of stars, insulated in the heavens, and constituting in itself a family or society apart from the rest, and subject to its own internal laws. It would be a vain task to attempt to count the stars in one of these globular clusters. They are not to be reckoned by hundreds; and on a rough calculation, grounded on the apparent intervals between them at the borders (where they are seen not projected on each other) and the angular diameter of the whole group, it would appear that many clusters of this description must contain at least ten or twenty thousand stars, compacted and wedged together in a round space, whose angular diame ter does not exceed eight or ten minutes; that is to say, in an area not more than a tenth part of that covered by the moon." The stars composing such clusters appear to form a system of a peculiar and definite character. "Their round figure clearly indicates the existence of some general bond of union in the nature of an attractive force, and in many of them there is an evident acceleration in the rate of condensation as we approach the centre, which is not referable to a merely uniform distribution of equidistant stars through a globular space, but marks an intrinsic density in their state of aggregation, greater at the centre than at the surface of the mass."

Let the reader pause for a moment on the object now described, and consider the glimpse it affords us of the immensity of the universe, and of the innumerable globes of light with which it is replenished. A point in the firmament, scarcely perceptible to the unassisted eye, which a common telescope shows only as a small, dim, round speck, yet is found by powerful instruments to consist entirely of stars to the number of ten or twenty thousand! At what a distance must such a cluster be when its stars appear to be blended and projected one upon another, hundreds of them appearing only like a lucid point! and yet the distance between any two of them is perhaps ten thousand times greater than that of Saturn from our globe. From such a region even light itself must take

many thousands of years ere it can reach our world. In this almost invisible point, which not one out of fifty thousand, or even one out of a million of earth's inhabitants has yet perceived, what a scene of grandeur and beneficence may be displayed; and what a confluence of suns, and systems, and worlds, and intelligences of various orders, may exist, displaying the power, and wisdom, and goodness of the great Father of all! Every circumstance connected with such an object shows that its distance must be immeasurably great, and, consequently, the luminaries of which it is composed immense in magnitude. But suns of such size and splendour cannot be supposed to be thrown together at random through the regions of infinity, without any ultimate design worthy of the Creator, or without relation to the enjoyments of intelligent existence; and therefore we may reasonably conclude, that ten thousand times ten thousands, and myriads of myriads of exalted intelligences exist in that far-distant region, compared with the number of which all the inhabitants of our globe are but " as the drop of a bucket, or as the small dust of the balance."

In short, in this dim and almost imperceptible speck we have concentrated a confluence of suns and worlds, at least ten times surpassing in size and splendour the sun, moon, and planets, and all the stars visible to the naked eye throughout all the spaces of our firmament! What, then, must be the number and magnitude of all the other clusters which the telescope has brought to view? what the number of those which lie beyond the limits of human vision in the unexplored regions of immensity? and what must the UNIVERSE itself be, of which all those numerous starry systems are but an inconsiderable part? Here the human faculties are completely lost amid the immensity of matter, magnitude, motion, and intelligent existence, and we can only exclaim, "Great and marvellous are thy works, Lord God Almighty!"

Figure 41 represents a view of one of the clusters alluded to above, as seen in the twenty-feet reflector at Slough. Sir J. Herschel, who has given a delineation of it in his "Treatise on Astronomy," says, "it represents, somewhat rudely, the thirteenth nebula of Messier's list, described by him as nebuleuse sans etoiles." Its right ascension is 16h 36', and its north declination 36° 46'; by which its place may easily be found on a celestial globe. It is situated in the constellation Hercules, between the stars 7 and . These stars are of the third

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magnitude, and lie north and south of each other, at the distance of seven degrees and a third; they come to the meridian about the middle of July, at nine o'clock in the evening, but of course may be seen at many other periods of the year, particularly in the spring and autumn. The star 7 lies about twenty-two degrees nearly due west from the bright star Vega or a Lyra. In the map of the stars on Plate II. it is marked with the letter a, and the star below it with the letter b. The cluster is somewhat nearer to 7, or the upper star, than to the other. It is just perceptible to the naked eye, and with a telescope of small power, such as a common "night and day telescope," it appears like a small round comet.

The following is a list of the places of six of the principal clusters of this description, which may be considered as specimens of these remarkable objects:

1. Right ascension, 15h 10'; north declination, 2° 44'. This cluster lies about eight degrees southwest from Unuk, the principal star in the Serpent, and comes to the meridian about the middle of June, at nine o'clock in the evening.

2. Right ascension, 13h 34'; north declination, 29° 15'; between the tail of Chara and the thigh of Bootes, about twelve degrees northwest of Arcturus, nearly on a line between that star and Cor Caroli, but nearer Arcturus.

3. Right ascension, 13h 5'; north declination, 19°5'; in Coma Berenices, fourteen degrees west by south of Arcturus. A line drawn from Arcturus through 7 Bootes meets this cluster at somewhat more than double the distance of these two stars.

4. Right ascension, 17h 29'; south declination, 3° 8'; between the stars y and μ of Serpentarius, but nearer to the latter.

5. Right ascension, 21h 25'; south declination, 1° 34'; in Aquarius, about five degrees north of 7 in the west shoulder, nearly in a line with & Pegasi, or Enif.

6. Right ascension, 21h 22'; north declination, 11° 26'. This cluster lies north from No. 5, at the distance of thirteen degrees, and about three or four degrees northwest of the star Enif, or e Pegasi.

Such are a few specimens of compressed clusters of stars. Sir W. Herschel has given a catalogue of more than a hundred of such clusters dispersed over different parts of the heavens, many of which require powerful telescopes to resolve

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them into stars. These clusters may be considered as so many distinct firmaments, distributed throughout the spaces of immensity, each of them comprising within itself an assemblage of stars far more numerous than what appears to the vulgar eye throughout the whole face of our nocturnal sky. To those intelligences that reside near the centre of such clusters, the stars connected with their own cluster or system will be those which they will chiefly behold in their sky; and in those clusters which are of a globular form, the stars will appear nearly equally dispersed over the face of their firmament. In those starry assemblages which show a great compression about the centre, an immense number of stars of the first magnitude will decorate their sky, and render it far more resplendent than that with which we are surrounded; another instance of that variety which distinguishes all the scenes of creation. Scarcely any other stars will be visible except those which belong to their own system. If the magnificent system of stars with which our sun is connected be at all visible, it will only appear like a dim and inconsiderable speck in the remote regions of immensity, or as a small cluster or nebula, such as those we perceive with difficulty through our telescopes. Such are the grand, the diversified, and wonderful plans of the Creator throughout his vast and boundless uni

verse.

CHAPTER XII.

ON THE DIFFERENT ORDERS OF THE NEBULE.

SECTION I.-General Remarks on the Subject of Nebula.

THE farther we proceed in our researches into the sidereal heavens, the scene of Creating Power and Wisdom becomes more expansive and magnificent. At every step of our progress the prospect enlarges far beyond what we had previously conceived; the multitude and variety of its objects are indefinitely increased; new suns and new firmaments open to view on every hand, overwhelming the mind with astonishment and wonder at the immensity of Creation, and leaving it no room

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