through the remoter parts of its orbit. In computing the periodic time of the comet of 1811, Lemaur assigned 775 years to the half of the ellipse nearest the sun, and 3462 to the more distant half. The appearance of this comet was strikingly ornamental to the evening sky. Many a reaper late in the harvest field stayed his hand, and many a peasant homeward-bound stopped in the way, to gaze upon the celestial novelty as it grew into distinctness with the declining day. The Ettrick shepherd has left a memorial of his impressions in the well-known lines:

"Stranger of heaven, I bid thee hail!

Shred from the pall of glory riven,
That flashest in celestial gale -

Broad pennon of the King of Heaven

"Whate'er portends thy front of fire,

And streaming locks so lovely pale;
Or peace to man, or judgments dire,
Stranger of heaven, I bid thee hail !"

NEBULA.-Far more astonishing than any of the details upon which we have hitherto dwelt, are those relating to the class of celestial objects we have now to consider, the investigation of which is at present the highest branch of practical astronomy. In directing our attention to Nebulæ, we leave what may comparatively be called home regions, strange as the phrase appears, when we recollect the distance intervening between us and the nearest of the stars. But such language is strictly appropriate with reference to the stars visible to the naked eye, and reached by ordinary telescopic aid. They form our firmament or cluster, near the centre of which the solar system is supposed to be situate, the Milky Way being apparently its outward boundary. Yet besides this province with which we are connected, incalculably vast as it is, perfectly inestimable both in length, breadth, depth, and height, there are other provinces within view, equally as capacious, distinct firmaments of clusters,

scattered through those territories of the universe that are accessible to our gaze; and could we be removed to any of them, the whole of that great scheme of existence circumscribed by the Milky Way, might seem compressed into a small globular patch in space, the aspect presented by the nebula to ourselves. The term nebula, signifying a cloud or mist, is a denomination given to spots of pale light, which are sprinkled in the heavens, a few of which may be detected by the unaided eye. They vary considerably in shape, size, and luminosity; and occur in numbers, which every improvement of the telescope increases.

It was one of the great tasks of Sir William Herschel to gauge the heavens, and to ascertain the relative distances of the resolved and resolvable clusters; and, as many of those views which were deemed wild and visionary by his compeers, have, since his day, been triumphantly established, his inquiries and conclusions in general are entitled to attention and confidence. To the centres of the easily resolved spherical nebulæ of the largest diameter, he assigned a remoteness 400 times that of Sirius. Those of half their diameter, whose stars appear to be more closely wedged, he supposed to be double the distance of the former; and at four times their distance, or 2400 times more remote than Sirius, he placed those clusters which plainly indicate resolvability, but whose components are not with our present means apprehensible. In the last case we have an extent of space equal to at least 45,000,000,000,000,000, or forty-five thousand billions of miles. The dumb-bell nebula is certainly not within that range, and probably much farther off. Light, which comes to us from the sun in eight minutes-flashing along at the immense rate of 190,000 miles in a second of time, or nearly twelve millions of miles in a minute, would require upwards of seven thousand years to perform its passage across the gulf! But Herschel went to a still more tremendous depth in space-that of 35,175 times the

distance of Sirius- as the site of some clusters;- a comparison with which the distance of the stars themselves from us, mighty as it appears, shrinks into insignificance. Such is Creation! or at least that part of it with which we have some acquaintance. These are views which render the language of Coleridge not chargeable with extravagance: "It is surely not impossible," said that highly gifted man, "that to some infinitely superior Being the whole universe may be as one plain-the distance between planet and planet being only as the pores in a grain of sand, and the spaces between system and system no greater than the intervals between one grain and a grain adjacent !”

Upon com

The dimensions of one of these nebula alone is so enormous, that it subtends an angle of nearly 10', and supposing it at the distance of a star of the eighth magnitude, its size must be at least 3,208,600,000,000,000,000, or more than three trillions of times that of our sun. paring the present appearance of this great nebula with former drawings of it, it appears to have undergone some marked changes, at least if the older representations are to be depended upon. The following memorandum was made by Herschel when he viewed it in 1774: "Its shape is not like that which Dr. Smith has delineated in his 'Optics,' though somewhat resembling it; from this we may infer that there are undoubtedly changes among the regions of the fixed stars; and perhaps, from a careful observation of this lucid spot, something may be concluded concerning the nature of it." What this immense looming mass portends, we know not, but the surmise is not improbable, that here we have the germ of systems of worlds to be evolved in future ages, where Life, Beauty, and Intelligence are destined to play their various phases.

An object of the same class appears in the girdle of Andromeda, called the "transcendently beautiful Queen of the nebulæ," the oldest known nebula, supposed also to be one of

the nearest. It is visible to the naked eye in the absence of the moon, and has often been mistaken for a comet. A notice of it occurs as early as the commencement of the tenth century. The first telescopic view was obtained by Simon Marius, December 15, 1612, who compared it to a candle shining through a horn, that is, a diluted light increasing in density towards a centre. This nebula is of an oval or lenticular shape, and forms nearly a right-angled triangle with Almaach Mirach, the two chief stars of Andromeda. A good eye may pick it up on a favorable night, by projecting a line from Sheratan, the second star in Aries, through Mirach to about 43° beyond. It is about half a degree long, and from 15' to 20' broad. Herschel, who deemed this one of the nearest nebula in the heavens, remarks: "The brightest part of it approaches to the resolvable nebulosity, and begins to show a faint red color; which from many observations on the magnitude and color of nebulæ, I believe to be an indication that its distance in the colored part does not exceed 2000 times the distance of Sirius." This is the rather extensive interval of 38,000,000,000,000,000, of miles, a space which light will require more than 6000 years to traverse, so that a ray that now meets the eye must have started from its source before the creation of man, and a ray that is now leaving it will not accomplish the distance till the world is six thousand years older.

Those who have treated the nebulæ hypothesis with ridicule have strangely forgotten what is daily passing before their eyes-forgotten the uniform plan of Providence with reference to the world in which we live. What is man full-grown, active, intellectual man-as he appears in the maturity of his powers, the noontide of his day, but an example of ascension from a crude to a higher condition? By gradual and slow degrees, he acquires his vigor of frame, fluency of speech, agility of movement, and furniture of mind. We have no more occasion to stumble at the idea that

our world dates its origin from a few primordial elements, endowed with properties to complete the structure, than a colony of ants, at a tree root, would have cause to start at the fact, could they be made cognizant of it, that leaves, branches, and trunk proceeded from a single seed. The law that unites the atoms that compose the earth, forms every rain-drop, and moulds the tear that trickles down the cheek of sorrow—in prevailing operation millions of leagues away from our terrestrial residence, binding together in spherical masses whole sidereal systems. Such a fact, however, commonly suggests no farther remarks than that the laws of nature every where prevail, and with this, thought in general ends. But "what," says Paley, "do we mean by the laws of nature, or by any law? Effects are produced by power, and not by laws. A law cannot execute itself. A law refers us to an agent." An irresistible conviction is forced upon us, of the universal agency, and, consequently, the omnipresence of one Lawgiver, by the universal presence and execution of kindred laws; and confessedly incomprehensible as is the modus of His operation, it would be not more irreligious to stumble at this than unphilosophical, considering the immense amount of things of which we have certain evidence that they are, without having any glimpse as to how they are. We cannot at all understand the physical agency of the Deity; but paying deference to the strong facts of nature, we are led to the conclusion that He

"Lives through all life, extends through all extent
Spreads undivided, operates unspent."

However it may savor of the gigantesque, it is sufficiently evidenced that an area of the heavens not exceeding

of the lunar diameter, contains a system of stars rivalling in number those which constitute our firmament, and appearing only as a single faint luminosity to us. Yet there are thousands of areas so occupied. It follows,