BY D. W. BELISLE.

LEO.—This is one of the most clearly defined and brilliant constellations in the winter hemisphere, containing an unusual number of very bright stars. It is situated east of Cancer, and comes to the meridian the sixth of this month. This constellation contains ninety-five stars visible to the naked eye.

Five very bright stars in this constellation are grouped in the form of a sickle. Regulus, in the shoulder of Leo, is the lowest of this group, and forms the end of the handle in the sickle. It is the brightest star in the cluster, and is of great use to nautical men in determining their longitude at sea. Eta, a small glittering star, marks the other end of the handle, while Al Gieba Adhafera, Ras al Asad, and Lambda form the blade. Two small stars, at an equal distance from Lambda, form a small right-angled triangle. Denebola, in the brush of the tail, is a star of the first magnitude, and, with Zozma in the back, and Theta in the thigh, form a triangle whose vertex is Denebola.

According to Greek mythology, the Lion was one of the formidable animals killed by Hercules in the forests of NemÆa, and was placed by Jupiter in the heavens to commemorate the event. Egyptian mythologists claim the honor of having placed it there, asserting it was placed in the heavens to commemorate the haunting of the banks of the Nile during the heat of summer by these monsters, the river then being at its highest elevation.

LEO MINOR.—This constellation is of modern origin, occupying the space between Ursa Major and Leo Major. The stars in the cluster are of the third and fourth magnitude, with no particular interest attached to them. It comes to the meridian the 6th of April.

SEXTANT.—This is a small constellation south of Leo, and contains forty-one stars, all very small and unimportant, and comes to the meridian the 6th of April. This constellation is sometimes called Urania's Sextant, in honor of one of the muses who presided over Astronomy. Urania was daughter of Jupiter and Mnemosyne.

HYDRA.—This is an extraordinary constellation, winding through a vast space from east to west for more than one hundred degrees. It lies south of Cancer, Leo, and Virgo, and reaches from Canis Minor to Libra. It contains sixty stars, principally of the second, third, and fourth magnitudes. The head of Hydra may readily be distinguished by four bright stars south of Acubens, in the Crab. They form a rhomboidal figure. The three upper stars form a beautiful curve, and are too distinct and conspicuous to be forgotten when once seen. Alphard, twenty-three degrees south south-west of Regulus, is a very brilliant star of the second magnitude, and is in the heart of Hydra, and comes to the meridian twenty minutes before nine o'clock on the 1st of April. When the head of the Hydra is on the meridian, its other extremity is many degrees below the horizon, so that its whole length cannot be traced out in the heavens until its centre is on the meridian.

According to mythology, the Hydra was a terrible monster that infested the Lake of Lerna, in the Peloponnesus. It was reported to have had a hundred heads, and, as soon as one of these was cut off, two grew in its place, unless the wound was stopped by fire.

The formidable monster was at last destroyed by Hercules, with the assistance of Iolaus, and who afterwards, dipping his arrows in the gall of the Hydra, rendered every wound inflicted by them incurable and mortal.

THE CUP.—This small constellation lies south of the Lion, and rests upon the Hydra. Six of the principal stars form a crescent or semi-circle, opening to the west. The crescent of the Cup is so striking and clearly defined, when the moon is absent, that no description is necessary to point it out, as it is the only one of the kind in that part of the heavens.

COMETS.—These objects of extraordinary interest form a part in the economy of the solar system. Since the time when the presence of a comet was considered by nations to be the sure precursor of war, famine, and pestilence, up to the present period, these visitors have created much speculation and excitement; and, no longer ago than the fall of 1853, it was predicted by an eminent "professor" that one of these waifs in the heavens would come in collision with the earth, and destroy a portion of China. This, however, like many other pieces of mischief which had been predicted it would accomplish, failed, and the professor has retired from observation covered with the laurels won by his research.

A comet, so brilliant that it could be seen at noonday, made its appearance seventy-three years before the birth of our Saviour. This date was just after the death of Julius CÆsar, and by the Romans the comet was believed to be his metamorphosed soul, armed with fire and vengeance. This comet appeared again in 1106, and then resembled the sun in brightness, being of great size, and having an immense trail.

In 1456, a large comet made its appearance. The terror it created extended through all classes, and the belief was universal that the day of judgment was at hand. At this time, the Turks, with their victorious armies, seemed destined to overrun all Europe. This added to the gloom and terror. The people became regardless of the present, and anxious only for the future. To prepare the world for its expected doom, Pope Callixtus III. ordered the Ave Maria to be repeated three times instead of twice a day, and to it was added, "Lord, save us from the Devil, the Turk, and the Comet!" and thrice each day these obnoxious personages suffered excommunication. At length, the comet began to retire from eyes in which it found no favor, and the Turks retired to their own dominions.

The comet of 1680 was of the largest size, having a trail ninety-six millions of miles in length. Dawning science, however, robbed it of its terrors, assisted by the signal failure of its illustrious predecessor.

Such are many of the fantasies which these peculiar visitors have called up. The beautiful comet of 1811, the most splendid of modern times, was considered, even by many intelligent persons, as the harbinger of the war which was declared the spring following; and the remembrance will be fresh in the minds of many of an indefinite apprehension of some dreadful catastrophe, which pervaded both continents, in anticipation of Bela's comet in 1832.

Comets, unlike the planets, observe no one direction in their orbits, but approach to and recede from their great centre of attraction in every possible direction. Some seem to come up from immeasurable depths below the ecliptic, and, having doubled the heaven's mighty cape, again plunged downward with their fiery trains,

"On the long travel of a thousand years."

Again, they seem to come from the zenith of the universe, and, after doubling their perihelion about the sun, reascend far above human vision. Others, again, seem to be dashing through the solar system in every conceivable direction, apparently in an undisturbed path; others are known, however, to obey laws like those which regulate planets. Nothing is known with certainty as to the composition of these bodies, although it is certain they contain very little matter, for they produce little or no effect on the motions of planets when passing near those bodies. Upon what errands they come, what regions they visit when they pass from view, what is the difference between them, the sun, and planets, and what is their mission in the economy of the universe, are questions often pondered over, but the solution of which is beyond the limited powers of human understanding.