Still, my own EDITH, wife, consoler, friend!
For thee I strive, for thee I toil to win
The laurels of a contest with the world;
For thee seek fortune, honors and renown.
But, after many months, again will smile

The golden Summer through his ripening sheaves,
And we will tread these leafy haunts again.
And though we cannot see red Autumn light
His fiery torches on these stately trees;
And though we cannot see the ermine robes
That Winter next will heap upon these banks,
Nor watch the feathers from his spotless doves
Fall in thick showers upon these mossy roofs;
Nor view the violets of the Spring unveil
Their moist, blue, bashful eyes beneath the soft,
Green, growing veil of verdure, ere it spreads
And deepens to a carpet for the ground;
Still will we, by our fireside's cheerful blaze,
Talk of such sights, and picture what they are.
Then take, sweet EVE, one last and lingering look
Of thy dear Eden, and go forth with me,

With this to cheer thee that no angel bars
Thy glad return, but that all lovely things
Will bid thee welcome in harmonious songs.

As early as the year 1612, the nebula in Andromeda was described by Simon Marius; but, from the writings of Ismael Bouillaud, a writer of the seventeenth century, it appears that this nebula was discovered much earlier than that period. It is probable, says a distinguished astronomer, that it was recognized at least six hundred years before the invention of the telescope. It excited much attention at the time, and has since become one of the most important nebulous appearances in the heavens. Another remarkable nebula, that in the sword of Orion, was discovered and described by Huygens, in 1657. This new discovery contributed to increase the interest and curiosity which its elder brother had excited. It was, however, reserved for Messier, an astronomer of the eighteenth century, to extend the catalogue of these mysterious bodies, and to lay the foundation for speculations of a most exciting character, which, while they threatened to unsettle established theories and cherished beliefs, have greatly increased our obligations to the science itself, and have led to those glorious achievements of the mind which dignify and ennoble mankind.

While this distinguished astronomer was engaged in observing comets, to which he devoted much of his time, he discovered one hundred and three objects, or nebulous islands, of a light hazy appearance, irregularly scattered through space. Under moderate telescopic power, these objects appeared as self-luminous islands of vapor; but, when examined with refractors of larger aperture and greater focal length, it was ascertained that many of them consisted entirely of stars, so closely crowded together, that their light blended in a single blaze at the centre. A few of these

bodies, however, were not so easily disposed of; among which, those in Andromeda and Orion are the principals: they defied the space-penetrating power of the finest instruments, and remained, until recently, wholly irresolvable.

The great variety of forms, and the difference in the appearance of these bodies, excited the curiosity, and engaged the time and attention, of successive astronomers, for nearly two centuries; but more especially that of Sir William Herschel, to whom the world is so largely indebted. After much laborious observation, he was enabled, in 1802, to present to the Royal Society a catalogue of two thousand newly-discovered nebulæ, which he had arranged in appropriate classes. These bodies were as irregular in their figures as they were in their distribution. They are,' says Sir John Herschel, of all degrees of eccentricity, from moderately oval forms to ellipses so elongated as to be almost linear. They varied in their ance, from that which seemed to be the irregular aggregation, merely, of self-luminous vapor, or 'star-dust,' to the oval island, in which the outlines of stellar bodies were clearly distinguishable.

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In Sir William's catalogue, these bodies were divided into globular and irregular clusters; resolvable nebulæ, or such as he believed would yield to increased optical power; nebulæ proper, in which there was no appearance of stars; planetary nebulæ, and nebulous stars. In some instances, the nebulæ presented the appearance of a faint luminous atmosphere, of a

circular form, and of large extent, surrounding a star of considerable brilliancy. These were considered, in the speculations which followed the discoveries, and to which we will soon invite the reader's attention, the oldest, or advanced stages of the nebulous matter; and were called stars with burrs, from the fact that their light increased from the borders to the centre. It was soon ascertained that the globular or oval nebulæ yielded readily to increased optical power; and that their appearance was the effect of their great distance from us. The irregular or elliptical clusters were less condensed at the centre; and although some of them, as the one in the girdle of Andromeda, could be seen with the unaided eye, they steadily maintained their nebulous appearance. It was thought, however, that they changed their appearance from time to time; but this was owing to the imperfect sketches taken of them, and the difference in the space-penetrating power of the telescopes used at the various periods.

It was these remarkable and distant bodies, appearing more or less distinct, according to their distance, which led Sir William Herschel to speculate on the gradual subsidence and condensation of the gaseous or elementary sidereal matter, which, it was thought, was dispersed through the regions of space. Assuming that in the progress of this subsidence, local centres of condensation, subordinate to the general tendency, would not be wanting, he conceived that in this way solid nuclei might arise, whose local gravitation still farther condensing, and so absorbing the nebulous matter, each in its immediate neighborhood might ultimately become stars, and the whole nebula finally take on the state of a cluster of stars. Among the multitude of nebulæ revealed by his telescopes, every stage of this process might be considered as displayed to our eyes, and in every modification of form to which the general principle might be conceived to apply. The more or less advanced stages of a nebula toward its aggregation into discrete stars, and these stars themselves towards a denser nucleus, would thus be in some sort indications of age.'

The lowest order, or rudimental nebulæ, were variable, both in their figures and degree of brightness. These, it was thought, represented the first stage of aggregation. The more advanced were distinguished from stars by the faint light only by which they were surrounded. It was not these appearances, however, which first aroused the active and vigilant mind of the elder Herschel. He felt fully persuaded that these bodies were simply congeries of stars, so far removed from us as to blend their light, and thus present these nebulous appearances; and that they were not caused by any inherent distinction. He was anxious, however, to become more intimately acquainted with these mysterious bodies, and therefore labored to apply some more certain and reliable test to them. He was gratified, as he supposed, in this desire; for while sweeping the heavens with his telescope, he discovered stars, shining, or appearing to shine, through floating clouds of this highly attenuated matter. These he thought to be 'stars enveloped in circular halos;' affording him an opportunity to contrast the true star with the nebulous matter surrounding it. It is difficult to imagine the anxiety and intense interest which agitated the mind of that great man, at this period of his glorious career. An opportunity to prove or disprove the suspicions which had perplexed his mind so long, now presented itself; and, believing the result of his observations to be of the

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greatest importance, he must have undertaken the task with feelings of
the most trying character. We will give the history of that observation
in his own language: In the first place,' he says, 'if the nebulosity
consist of stars that are very remote, which appear nebulous on account
of the small angles their mutual distance subtends to the
eye, whereby
they will not only, as it were, run into one another, but also appear ex-
tremely faint and diluted; then what must be the enormous size of the
central point, which outshines all the rest in so superlative a degree as to
admit of no comparison! In the next place, if the star be no bigger than
common, how very small and compressed must be those other lumi-
nous points, that are the occasion of the nebulosity which surrounds the
central one! As by the former supposition, the luminous central point
must far exceed the standard of what we call a star, so, in the latter, that
shining matter about the centre will be much too small to come under
this denomination: we therefore either have a central body which is not
a star, or have a star which is involved in a shining fluid of a nature
totally unknown to us. I can adopt no other sentiment than the latter,
since the probability is certainly not for the existence of so enormous a
body as would be required to shine like a star of the eighth magnitude,
at a distance sufficiently great to cause a vast system of stars to put on
the appearance of a very diluted milky nebulosity.' Thus we find one
great astronomer laying the foundation for conjectures and theories, which
have interested, and will continue to interest mankind, so long as there is
any doubt about these bodies, or so long as there is any outward twilight
into which the inquiring mind can penetrate. Sir William had wandered
into the dim distance, until lost mid the shadows and darkness of unexplored
regions, and was forced to adopt the course which appeared to be supported
by the strongest probabilities. One of the positions increased his bewil-
derment; while the other pointed out the way of return, but left him
standing astounded by his own discoveries, and the startling deductions to
which they must inevitably lead.

There were other phenomena, however, which greatly contributed to establish the idea of a phosphorescent vapor, or elementary form of luminous sidereal matter; the most important of which is known as the zodiacal light, which is seen after sunset during the spring months, and before sunrise during the fall. It is a cone of lenticularly-shaped light, extending from the horizon obliquely upward, following generally the course of the ecliptic, or rather that of the sun's equator. This was then thought to be a residuum of the nebulous matter, or star-dust, collected around the sun. An acceleration discovered in the motion of the moon, which, it was supposed, resulted from the resistance of an ethereal medium in which the heavenly bodies revolved, also united with the various concurring phenomena to establish the belief in the existence of this highly attenuated vapor, out of which Nature elaborated her suns and planetary systems by the powers of attraction and gravitation. This belief was favored by the crepuscular theory of light. It was supposed that the waste of the celestial bodies, by the perpetual diffusion of their light, was compensated by this collecting and condensing process, and the balance of the system restored by the formation of new planets and stars. And not only these; it was also supported by the general harmony that pre

vailed throughout the mechanism of the whole system. This harmony, so delightful to the astronomer, could be most satisfactorily accounted for by supposing the planets to have been thrown off by the sun, while the great luminary was contracting his dimensions under the influence of radiation, or by centrifugal force, as the mighty primary swept around with incalculable speed. It was contended that the dimensions of the nebulous matter, which extended beyond the orbit of the most distant planet, were contracted by loss of heat through radiation; and that rotary motion was produced by the force of the outward particles rushing to the centre.

These speculations of the elder Herschel, concerning the possible aggregation of the self-luminous particles, and their condensation into planets, were followed by the Nebular Hypothesis' of La Place, a philosopher whose varied and profound attainments enabled him to systematize the speculations of others, and to erect a glorious temple in honor of man, out of the rich material which the learned and great of all preceding ages had scattered around his feet. It was suggested, in his celebrated hypothesis, that the stars and planets were originally the same as the supposed nebulous bodies, and that they had passed regularly through the various stages of advancement or growth necessary to prepare them for the habitation of animate matter; and that when, in the course of this natural process, they were fitted for the great offices of life, they were left under the influence of certain arbitrary physical laws, to perform their part in the innumerable and brilliant sisterhood.

The first motion of this infant world of attenuated vapor, thrown off by laws originally stamped on matter itself, strikes the student with astonishment, barely sufficient to prepare him for the future revelations of which these early evidences of life are but feeble intimations. Innumerable centuries of time shall witness the changes now commenced, divided only by the immeasurable periods required for the birth of new planets or planetary systems. The first and eldest of the sisterhood, sweeping around the outward horizon, will be lost in darkness long before the junior members are prepared to cheer it with the warmth and gladness of the parent light.

The existence of the nebulous matter appeared to be satisfactorily proved by these phenomena. Nothing now remained to perplex the minds of astronomers. But other questions presented themselves equally interesting; indeed it was these subsequent questions which gave the first so much importance. How far did the great primary nebula extend? From whence did it come, and what is its destiny? The nebular hypothesis begins by supposing it to have originally extended beyond the orbit of the most distant planet, and that by loss of heat, through radiation, it contracted its dimensions; and that it was thrown into rotary motion by the force of the inward rushing of the outward particles to the centre. This motion gave birth to centrifugal force, which depends on rotary motion for its existence. This centrifugal force continued to increase, until it threw off the external particles into a separate zone or ring, as the rings of Saturn. These were broken up by some imaginary influence, and the particles again drawn together by the attractive power of a central point, which became the nucleus of the new-born planet. This planet in its turn is thrown into motion by the same forces, and throws off other rings,