Astronomers divide the heavens into three parts, called the northern and southern hemispheres, and the Zodiac. In the northern hemisphere, astronomers usually reckon thirty-four constellations; in the Zodiac twelve, and in the southern hemisphere forty-seven; making, in all, ninety-three. Besides these, there are a few of inferior note, recently formed, which are not considered sufficiently important to be particularly described.

About the year 1603, John Bayer, a native of Germany, invented the convenient system of denoting the stars in each constellation by the letters of the Greek alphabet, applying to the largest star the first letter of the alphabet; to the next largest the second letter, and so on to the last. Where there are more stars in the constellation than there are Greek letters, the remainder are denoted by the letters of the Roman alphabet, and sometimes by figures. By this system of notation, it is now as easy to refer to any particular star in the heavens, as to any particular house in a populous city, by its street and number.

Before this practice was adopted, it was customary to denote the stars by referring them to their respective situations in the figure of the constellation to which they severally belonged, as the head, the arm, the foot, &c.

It is hardly necessary to remark that these figures, which are all very curiously depicted upon artificial globes and maps, are, purely, a fanciful invention-answering many convenient ends, however, for purposes of reference and classification, as they enable us to designate with facility any particular star, or cluster of stars; though these clusters very rarely, if ever, represent the real figures of the object whose names they bear. And yet it is somewhat remarkable that the name of "Great Bear," for instance, should have been given to the very same constellation by a nation of American aborigines, (the Iroquois,) and by the most ancient Arabs of Asia, when there never had been any communication between them! Among other nations, also, between whom there exists no evidence of any intercourse, we find the Zodiac divided into the same number of constellations, and these distinguished by nearly the same names, representing the twelve months, or seasons of the year.

The history of this whimsical personification of the stars carries us back to the earliest times, and introduces us, as we have seen, to the languages and customs, the religion and

How do astronomers usually divide the heavens, and what is the number of constellations in each division? What convenient system of notation has been invented for denoting the stars in each constellation? Who invented this system? Before this method was introduced, what was the practice?

poetry, the sciences and arts, the tastes, talents, and peculiar genius, of the early nations of the earth. The ancient Atlautides and Ethiopians, the Egyptian priests, the magi of Persia, the shepherds of Chaldea, the Bramins of India, the mandarins of China, the Phoenician navigators, the philosophers of Greece, and the wandering Arabs, have all added more or less to these curious absurdities and ingenious inventions, and have thus registered among the stars, as in a sort of album, some memorial of themselves and of the times in which they lived. The constellations, or the uncouth figures by which they are represented, are a faithful picture of the ruder stages of civilization. They ascend to times of which no other record exists; and are destined to remain when all others shall be lost. Fragments of history, curious dates and documents relating to chronology, geography, and languages, are here preserved in imperishable characters. The adventures of the gods, and the inventions of men, the exploits of heroes, and the fancies of poets, are here spread out in the heavens, and perpetually celebrated before all nations. The Seven stars, and Orion, present themselves to us, as they appeared to Amos and Homer: as they appeared to Job, more than 3000 years ago, when the Almighty demanded of him"Knowest thou the ordinances of heaven? Canst thou bind the sweet influences of the PLEIADES, or loose the bands of ORION? Canst thou bring forth MAZZAROTH in his season, or canst thou guide ARCTURUS with his sons ?" Here, too, are consecrated the lyre of Orpheus, and the ship of the Argonauts; and, in the same firmament, glitter the mariner's compass and the telescope of Herschel.

CHAPTER XIV.

NUMBER, DISTANCE, AND ECONOMY OF THE STARS.

THE first conjecture in relation to the distance of the fixed stars, is, that they are all placed at an equal distance from the observer, upon the visible surface of an immense concave vault, which rests upon the circular boundary of the world, and which we call the Firmament.

We can with the unassisted eye, form no estimate of their respective distances; nor has the telescope yet enabled us to arrive at any exact results on this subject, although it has revealed to us many millions of stars that are as far removed

What is the first conjecture which we form in relation to the distances of the fixed stars? What means have we for ascertaining their number and distance?

beyond those which are barely visible to the naked eye, as these are from us. Viewed through the telescope, the heavens become quite another spectacle-not only to the understanding, but to the senses. New worlds burst upon the sight, and old ones expand to a thousand times their former dimensions. Several of those little stars which but feebly twinkle on the unassisted eye, become immense globes, with land and water, mountains and valleys, encompassed by atmospheres, enlightened by moons, and diversified by day and night, summer and winter.

Beyond these are other suns, giving light and life to other systems, not a thousand, or two thousand merely, but multiplied without end, and ranged all around us, at immense distances from each other, attended by ten thousand times ten thousand worlds, all in rapid motion; yet calm, regular and harmonious-all space seems to be illuminated, and every particle of light a world.

It has been computed that one hundred millions of stars which cannot be discerned by the naked eye, are now visible through the telescope. And yet all this vast assemblage of suns and worlds may bear no greater proportion to what lies heyond the utmost boundaries of human vision, than a drop of water to the ocean; and, if stricken out of being, would be no more missed, to an eye that could take in the universe, than the fall of a single leaf from the forest.

We should therefore learn, (says an eminent divine of the present century,*) not to look on our earth as the universe of God, but as a single, insignificant atom of it; that it is only one of the many mansions which the Supreme Being has created for the accommodation of his worshippers; and that he may now be at work in regions more distant than geometry ever measured, creating worlds more manifold than numbers ever reckoned, displaying his goodness, and spreading over all, the intimate visitations of his care.

The immense distance at which the nearest stars are known to be placed, proves that they are bodies of a prodigious size, not inferior to our sun, and that they shine, not by reflected rays, but by their own native light. It is therefore concluded, with good reason, that every fixed star is a sun, no less spacious than ours, surrounded by a retinue of planetary worlds, which

* Chalmers.

How do the heavens appear through the telescope? What are beyond those little stars which are scarcely visible to the naked eye? How many stars are visible through the telescope? What proportion may this vast assemblage of suns and worlds bear to what lies beyond the utmost boundaries of human vision? How should we learn from this to regard our own earth? What does the immense distance of the stars prove in regard to their magnitude and light?

revolve around it as a centre, and derive from it light and heat, and the agreeable vicissitudes of day and night.

These vast globes of light, then, could never have been designed merely to diversify the voids of infinite space, nor to shed a few glimmering rays on our far distant world, for the amusement of a few astronomers, who, but for the most powerful telescopes, had never seen the ten thousandth part of them. We may therefore rationally conclude, that wherever the All-wise Creator has exerted his creative power, there also he has placed intelligent beings to adore his goodness.

Hipparchus, the father of astronomy, first made a catalogue of the fixed stars. It contained 1022. The accuracy with which the places of these were recorded, has conferred essential benefit upon the science, and has enabled us to solve many celestial phenomena and problems of chronology, which other. wise had been difficult.

During the 18th century, upwards of 100,000 were catalogued by the various astronomers of Europe, and their position in the heavens determined with_an exactness that seldom varied a second from the truth; insomuch that it has been justly remarked, that "there is scarcely a star to be seen in the heavens, whose place and situation is not better known than that of most cities and towns upon the earth."

But the stargazers of our times are not idle. Professor Bessell of Konigsberg, observed in three years, it is asserted, between 30,000 and 40,000 stars, comprehended within a zone of 150 on each side of the equator; but even this great number is but a small portion of the whole number which lie within the limit of the zone which he examined. To procure a more complete survey, the academy of Berlin proposed that this same zone should be parcelled out among twenty-four observers, and that each should confine himself to an hour of right ascension, and examine it in minute detail. This plan was adopted; and the 18th hour was confided to Professor Inghirami, of Fiorence, and examined with so much care, that the positions of 75.000 stars in it, have been determined. Professor M. Struve, of the Dorpat university, has examined in person, 120,000 stars, of which 800 (double ones) were before unknown to science.

The labours of Sir Wm. Herschel were chiefly devoted to exploring the systems of nebula and double stars that lie, for the most part, beyond the reach of ordinary telescopes. No fewer than two thousand five hundred nebulæ were observed by this indefatigable astronomer, whose places have been computed from his observations, reduced to a common epoch, and arranged into a catalogue in order of their right ascension, by his sister MISS CAROLINE HERSCHEL, a lady so justly celebrated in Europe for her astronomical knowledge and dis coveries, but whose name, strange as it is, is seldom mentioned in this country. Be it remembered, nevertheless, for her fame, that she discovered two of the satellites of the planet which bears her brother's name, besides a multitude of

comets.

The greatest possible ingenuity and pains have been taken by astronomers to determine, at least, the approximate distance of the nearest fixed stars. If they have hitherto been unable to arrive at any satisfactory result, they have at least, established a limit beyond which the stars must necessarily be placed. If they have failed to calculate their true distances from the earth, it is because they have not the requisite data. The solution of the problem, if they had the data, would not be more difficult than to compute the relative dis

What conclusion may be drawn from this fact as to their great design? What pains have astronomers taken to find the distance of the stars, and what result have they come to? For what reason have they failed to calculate their distance? Is the problem a difficult one?

tances of the planets-a thing which any school-boy can do. In estimating so great a distance as the nearest fixed star, it is necessary that we employ the longest measure which astronomy can use. Accordingly, we take the whole diameter of the earth's orbit, which, in round numbers, is 190 millions of miles, and endeavour, by a simple process in mathematics, to ascertain how many measures of this length are contained in the mighty interval which separates us from the stars.

The method of doing this can be explained to the apprehension of the pupil, if he does not shrink from the illustration, through an idle fear that it is beyond his capacity.

For example; suppose that, with an instrument constructed for the purpose, we should this night take the precise bearing or angular direction from us of some star in the northern hemisphere, and note it down with the most perfect exactness, and, having waited just six months, when the earth shall have arrived at the opposite point of its orbit, 190 millions of miles east of the place which we now occupy, we should then repeat our observation upon the same star, and see how much it had changed its position by our travelling so great a distance one side of it. Now it is evident, that if it changes its apparent position at all, the quantity of the change will bear some proportion to the distance gone over; that is, the nearer the star, the greater the angle; and the more remote the star, the less the angle. It is to be observed, that the angle thus found, is called the star's Annual Parallax.

But it is found by the most eminent astronomers of the age, and the most perfect instruments ever made, that this parallax does not exceed the four thousandth part of a degree, or a single second; so that, if the whole great orbit of the earth were lighted up into a globe of fire 600 millions of miles in circumference, it would be seen from the nearest star only as a twinkling atom; and to an observer placed at this distance, our sun, with its whole retinue of planetary worlds, would occupy a space scarcely exceeding the thickness of a spider's web.* If the nearest of the fixed stars are placed at

* A just idea of the import of this term, will impart a force and sublimity to an expression of St. James, which no power of words could improve. It is said, Chapter I. verse 17., of Him from whom cometh down every good and perfect gift, that there is (6 ουκ ενι παραλλαγη η τροπης αποσκίασμα. "Literally, There is "neither parallar nor shadow of change:" As if the apostle had said-Peradventure, that in travelling millions and millions of miles through the regions of immensity, there may be a sensible parallax to some of the fixed stars; yet, as to the Father of Lights, view him from whatever point of his Empire we may, he is without parallax or shadow of change!

What measure is employed in estimating the distances of the fixed stars? How is it used? What is the angle thus found called? What is the greatest magnitude of the annual parallax?