to accomplish a revolution in 24 hours. The with the rapidity with which the fixed stars must move though sufficiently startling, are nothing when compared

distance

The 12 primary planets are distinguished by the annexed characters, viz. Mercury. Venus. The Earth. Mars. Vesta. Juno. Ceres. Pallas. Jupiter. h Saturn. The Georgium Sidus or Herschel. Neptune. The diagram shows the relative magnitudes of eight of these planets. The line in the margin on the left hand is the sun's semi-diameter on the same scale. The two circles in the centre show the comparative size of the earth and moon. The lines on the right exhibit the inclination of the orbits of the planets, with their mean distances from the sun.

in a second, to enable a body to pass over it in 24 hours. motion considerably greater than a thousand millions of miles 20,000,000,000,000 miles,-a space which would require a of the nearest of these suns (for suns they are) is at least

This certainly is a velocity far beyond what we are accustomed to conceive; and yet the velocity of the majority of the fixed stars would be infinitely greater than this. If you consider, therefore, the simplicity of the means employed, and the saving of labour effected by the rotation of the earth on its axis, instead of the revolution of the whole heavens, you can hardly fail to conclude the former to be the true theory of the celestial motions.

This conclusion must appear still more probable, if you attend to the bulks of these different bodies. Of the planets, three greatly exceed the earth in size-Jupiter being nearly 1500 times, Saturn 900 times, and Herschel 80 times larger. The sun is considerably more than a million times the size of the earth; and each of the fixed stars is probably as large as the sun. Such being the magnitude of these bodies, how inconsistent is it with every idea of order to suppose that such immeasurable masses are daily revolving round our comparatively insignificant globe!

But the most satisfactory proof of the earth's motion is derived from the form of the earth itself, and from certain variations in the force of gravity, observed at different parts of its surface. It is found that a clock goes considerably slower at the equator than towards the poles, so that it is necessary, for example, at the equator, to shorten the pendulum 4th of an inch in order to make the time correspond with that of London. How is this to be accounted for? It is not the heat of the climate, though that has the effect of lengthening metallic pendulums; for at Quito, which is covered with snow, the retardation of the clock is the same as at Cayenne. Nor is it the diminution of gravity at the equator, which necessarily causes the pendulum to move more slowly (as the pendulum is an index of the force of gravity);* for, after allowance is made for this, there still remains a considerable retardation to be accounted for.

*The earth has been determined by actual measurement to be an oblate spheroid, flattened towards the poles and protuberant at the equator; and the force of gravity decreases as we pass from the poles to the equator, its action being always from the centre of the earth.

The rotation of the earth alone affords a complete solution of the difficulty. By revolving on its axis, the earth acquires what is called a centrifugal force, which has the effect of diminishing the force of gravity at its surface. But the degree of rotation might be such as entirely to destroy the force of gravity, and even to sweep the waters from the earth's surface, as we see the water fly off from a wet mop in twirling it round with the hand;—or the motion might be so slow as scarcely to prevent the waters from quitting the elevated land at the equator, and flowing towards the lower land at the poles. It is a subject of calculation, therefore, what degree of rotation is necessary to keep the waters uniformly spread out over the whole surface, and, at the same time, to produce that degree of diminution in the action of gravity which is indicated by the retardation of the clock. Now the result of this calculation shows that a rotation of about 24 hours is precisely the degree of velocity requisite for producing these effects.

Compiled.

THE MOON AND STARS: A FABLE.

Ar the close of the fourth day of creation, when the sun, after a glorious but solitary course, had gone down, and darkness had begun to gather over the face of the yet uninhabited earth, a star-a single star and beautiful-stept forth in the firmament. Trembling with wonder and delight in new-found existence, she looked abroad, and beheld nothing in heaven nor on earth resembling herself. But she was not long alone. Now one, then another, then a third resplendent companion joined her, till, in the lapse of an hour, the whole hemisphere was bespangled with planets and fixed stars, and with a superb comet which flamed in the zenith.

These orbs for a while contemplated themselves and each other; and every one, from the largest to the least, imagined herself the central luminary of the whole universe. Nor were they undeceived regarding themselves, though all saw their associates in their relative proportions-self-knowledge

being the last knowledge acquired in the sky or below ittill, bending over the ocean, they beheld their individual forms reflected beneath, according to their places and configurations above. By an attentive self-inspection in that mirror, they slowly learned humility-all, except the comet, who, having a long train of brightness streaming sunward, continued to regard herself as the Queen of the hemisphere.

While thus examining themselves and each other, their attention was attracted by a slender thread of light, which shone out for a little above the horizon, and then vanished. This was the moon,-the first new moon. Timidly she looked upon the glittering multitude; and as she perceived how mean her scanty and unshapen form appeared in presence of their perfect symmetry, she seemed glad to hide herself from their glances in the friendly bosom of the ocean. When she was gone, the stars looked one at another with inquisitive surprise, as much as to say, "What a figure!" and they soon began to talk freely concerning her. But while they were ridiculing her crooked shape and her shyness, a sudden sense of their own fading splendour came over them. The east began to dawn; and, to their consternation, they all felt themselves fainting into invisibility, and, as they feared, into nothingness.

The next evening, the vanished celestials awoke gradually, and, on opening their eyes, were rejoiced to perceive that not one was wanting of last night's levee. The little gleaming horn, too, was again discerned, bending backward over the western hills; but, though somewhat brighter than on the former occasion, she again sunk early beneath the horizon, leaving the comet in proud possession of the sky.

On the third evening, the moon was so obviously increased in size and splendour, and stood so much higher in the firmament than at first, though she still hastened out of sight, that she was the sole subject of conversation on both sides of the galaxy, till the breeze, that awakened newly created man from his first slumber in Paradise, warned the stars to retire, and the sun, with a pomp never witnessed in our degenerate days, ushered in the first Sabbath of creation. The following night, the moon took her station still higher, and

looked brighter than before, insomuch that it was remarked of the lesser stars in her vicinity, that many of them were paler, and some no longer visible. As their associates knew not how to account for this, they naturally enough presumed that her light was fed by the absorption of theirs; and the alarm became general that she would thus continue to thrive by consuming her neighbours, till she had incorporated them all with herself.

Though thus growing larger and lovelier every night, the moon preserved her humility, till her crescent swelled into a gibbous form. Then, however, she began to feel proud of her preferment. Her rays, too, became so dazzling, that fewer and fewer of the stars could endure her presence: even the comet became wan before her. On the night of her fulness, she triumphed gloriously in mid-heaven, and arrayed the earth in softer day. Over the ocean she hung, enamoured of her own beauty, reflected in the abyss. And the few stars that still continued to sparkle in the firmament shrunk into bluer depths of ether, to gaze at a safe distance upon her all-conquering resplendence.

The moon herself was not a little puzzled to imagine to what size and splendour she might grow. Her vanity suggested that, although she had reached her full form, she had not reached her full size. Might she not go on increasing till man and his companion, woman, looking upward from the bowers of Eden, would see the heaven all moon? But, in the midst of this self-pleasing illusion, a film crept upon her, which spread from her utmost verge athwart her centre, till it completely eclipsed her visage, and made her a blot on the tablet of the heavens. In the progress of this disaster, the stars, which were hid in her pomp, stole forth to witness her humiliation. But their transport and her shame lasted not long the shadow retired gradually as it had advanced, leaving her fairer, by contrast, than before.

Another day went, and another night came; and she rose, as usual, a little later. Even while she travelled above the land, she was haunted with the idea that her lustre was rather feebler than it had been; but when she beheld her face in the sea, she could no longer overlook the