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world, and seem to observe a kind of equilibrium, like a balance.
When, however, it is said that the vernal and autumna equinoxes are in Aries, and Libra, and the tropics in Cancer and Capricorn, it must be remembered that the signs Aries and Libra, Cancer and Capricorn, and not the constellations of these names are meant; for the equinoxes are now in the constellations Pisces and Virgo, and the tropics in Gemini and Sagittarius; each constellation having gone forward one sign in the ecliptic.
About 22 centuries ago, the constellation Libra coincided with the sign Libra; but having advanced 30° or more in the ecliptic, it is now in the sign Scorpio, and the constellation Scorpio is in the sign Sagittarius, and so on.
While Aries is now advanced a whole sign above the equinoctial point into north declination, Libra has descended as far below it into south declination.
Libra contains fifty-one stars, including two of the 2d magnitude, two of the 3d, and twelve of the 4th. Its mean declination is 8° south, and its mean right ascension 226°. Its centre is therefore on the meridian about the 22d of June.
It may be known by means of its four principal stars, forming a quadrilateral figure, lying northeast and southwest, and having its upper and lower corners nearly in a line running north and south. The two stars which form the N. E. side of the square, are situated about 7° apart, and distinguish the Northern Scale. The two stars which form the S. W. side of the square, are situated about 6° apart, and distinguish the Southern Scale.
Zubeneschamali, in the Southern Scale, about 21° E. of Spica, and 8° E. of Lambda Virginis, is a star of the 2d magnitude, and is situated very near the ecliptic, about 4210 E. of the autumnal equinox. The distance from this star down to Theta Centauri, is about 23°, with which, and Spica Virginis, it forms a large triangle, on the right.
Zubenelgemabi, the uppermost star in the Northern Scale, is also of the 2d magnitude, 910 above Zubeneschamali, towards the northeast, and it comes to the meridian about twenty-six minutes after it, on the 23d of June. Zubenelge. mabi is the northernmost of the four bright stars in this figure, and is exactly opposite the lower one, which is 11° south of it.
Zubenhakrabi, is a star of the 3d magnitude in the Northern Scale, 7° S. E. of Zubenelgemabi, and nearly opposite to Zubeneschamali, at the distance of 11° on the east. These two make the diagonal of the square east and west.
Iota, is a star of the 3d magnitude, and constitutes the southernmost corner of
When it is said that the vernal and autumnal equinoxes are in Aries and Libra, and the tropics in Cancer and Capricorn, what is meant? In what constellations, then, are the equinoxes and the tropics situated? When did the constellation of Libra coincide with the sign of that name? In what sign is the constellation Libra now situated What are the number and magnitude of the stars in Libra? What are its right ascension and declination? When is its centre on the meridian? How may this constellation be known? What figure do the three upper stars in this figure form? What stars distinguish the Northern Scale? What the Southern? Describe Zubeneschamali. With what other stars does it form a large triangle? Describe the principal star in the Northern Scale. Describe the position of Zubenhakrabi. Describe the position of Iota.
the square. It is about 60 S. E. of Zubeneschamali, and 11° S. of Zubenelge. mabi, with which it forms the other diagonal north and south.
Zelenelgubi, is a star of the 3d magnitude, situated below the Southern Scale, at the distance of 6° from Iota, and marks the southern limit of the Zodiac. It is situated in a right line with, and nearly midway between, Spica Virginis and Beta Scorpionis; and comes to the meridian nearly at the same moment with Nekkar, in the head of Bootes.
The remaining stars in this constellation are too small to engage attention.
The scholar, in tracing out this constellation in the heavens, will perceive that Lambda and Mu, which lie in the feet of Virgo on the west, form, with Zubenes. chamali and Zubenelgemabi, almost as handsome and perfect a figure, as the other two stars in the Balance do on the east.
HISTORY.-The Libra of the Zodiac, says Maurice, in his Indian Antiquities, is perpetually seen upon all the hieroglyphics of Egypt; which is at once an argument of the great antiquity of this asterism, and of the probability of its having been originally fabricated by the astronomical sons of Misraim. In some few zodiacs, Astræa, or the virgin who holds the balance in her hand as an emblem of equal justice, is not drawn. Such are the zodiacs of Estne and Dendera. Humboldt is of opinion, that although the Romans introduced this constellation into their zodiac in the reign of Julius Cesar, still it might have been used by the Egyptians and other nations of very remote antiquity
It is generally supposed that the figure of the balance has been used by all nations to denote the equality of the days and nights, at the period of the sun's arriving at this sign. It has also been observed, that at this season there is a greater uniformity in the temperature of the air all over the earth's surface.
Others affirm, that the beam only of the balance was at first placed among the stars, and that the Egyptians thus honoured it as their Nilometer, or instrument by which they measured the inundations of the Nile. To this custom of measuring the waters of the Nile, it is thought the prophet alludes, when he describes the Almighty as measuring the waters in the hollow of his hand.—Isa. xl. 12. The ancient husbandmen, according to Virgil, were wont to regard this sign as indicating the proper time for sowing their winter grain:
"But when Astræa's balance, hung on high,
The Greeks declare that the balance was placed among the stars to perpetuate the memory of Mochus, the inventor of weights and measures.
Those who refer the constellations of the Zodiac to the twelve tribes of Israel, ascribe the Balance to Asher.
THE SERPENT.-There are no less than four kinds of serpents placed among the constellations. The first is the Hydra, which is situated south of the Zodiac, below Cancer, Leo and Virgo; the second is Hydrus, which is situated near the south pole; the third is Draco, which is situated about the north pole; and the fourth is the Serpent, called Serpens Ophiuchi, and is situated chiefly between Libra and Corona Borealis. A large part of this constellation, however, is so blended with Ophiuchus, the Serpent-Bearer, who grasps it in both hands, that the concluding description of it will be deferred until we come to that constellation.
"The Serpens Ophiuchi winds his spire
What star in this constellation marks the southern limit of the Zodiac? How many kinds of serpents have been placed among the constellations? Mention them, and their situations. With what is a large part of this constellation blended 1
One of the second rank; ten shun the sight;
Those stars which lie scattered along for about 25°, in a serpentine direction between Libra and the Crown, mark the body and head of the Serpent.
About 10° directly S. of the Crown there are three stars of the 3d magnitude, which, with several smaller ones, distinguish the head.
Unuk, of the 2d magnitude, is the principal star in this constellation. It is situated in the heart, about 10° below those in the head, and may be known by its being in a line with, and between, two stars of the 3d magnitude-the lower one, marked Epsilon, being 210, and the upper one, marked Delta, about 50 from it. The direction of this line is N. N. W. and S. S. E. Unuk may otherwise be known by means of a small star, just above it, marked Lambda.
In that part of the Serpent which lies between Corona Borealis and the Scales, about a dozen stars may be counted, of which five or six are conspicuous.
For the remainder of this constellation, the student is referred to Serpentarius.
"Vast as the starry Serpent, that on high
Tracks the clear ether, and divides the sky,
And southward winding from the Northern Wain,
Shoots to remoter spheres its glittering train."-Statius.
HISTORY.-The Hivites, of the Old Testament, were worshippers of the Serpent, and were called Ophites. The idolatry of these Ophites was extremely ancient, and was connected with Tsabaism, or the worship of the host of heaven. The heresy of the Ophites, mentioned by Mosheim in his Ecclesiastical History, originated, perhaps, in the admission into the Christian church of some remnant of the ancient and popular sect of Tsabaists, who adored the celestial Serpent. According to ancient tradition, Ophiuchus is the celebrated physician Escu lapius, son of Apollo, who was instructed in the healing art by Chiron the Centaur; and the serpent, which is here placed in his hands, is understood by some to be an emblem of his sagacity and prudence; while others suppose it was designed to denote his skill in healing the bite of this reptile. Biblical critics imagine that this constellation is alluded to in the following passage of the book of Job:
"By his spirit He hath garnished the heavens; his hand hath formed the crooked serpent." Mr. Green supposes, however, that the inspired writer here refers to Draco, because it is a more obvious constellation, being nearer the pole where the constellations were more universally noticed; and moreover, because it is a more ancient constellation than the Serpent, and the hieroglyphic by which the Egyptians usually represented the heavens.
THE NORTHERN CROWN.-This beautiful constellation may be easily known by means of its six principal stars, which are so placed as to form a circular figure, very much resem
What stars mark the head and body of, the Serpent? Describe the principal star in How this constellation. How may it be known? What stars distinguish the head? many stars may be counted in that part of the constellation which lies between Corona Borealis and the Scales? How may Corona Borealis be easily known?
bling a wreath or crown. It is situated directly north of the Serpent's head, between Bootes on the west and Hercules on the east.
This asterism was known to the Hebrews by the name of Ataroth, and by this name the stars in Corona Borealis are called, in the East, to this day.
Alphacca, of the 3d magnitude, is the brightest and middle star in the diadem, and about 110 E. of Mirac, in Bootes. It is very readily distinguished from the others both on account of its position and superior brilliancy. Alphacca, Arcturus, and Seginus, form nearly an isosceles triangle, the vertex of which is at Arcturus.
This constellation contains twenty-one stars, of which only six or eight are conspicuous; and most of these are not larger than the 3d magnitude. Its mean declination is 30° north, and its mean right ascension 235°; its centre is therefore on the meridian about the last of June, and the first of July.
"And, near to Helice, effulgent rays
Beam, Ariadne, from thy starry crown:
HISTORY.-This beautiful little cluster of stars is said to be in commemoration of a crown presented by Bacchus to Ariadne, the daughter of Minos, second king of Crete. Theseus, king of Athens, (1235 B. C.,) was shut up in the celebrated labyrinth of Crete, to be devoured by the ferocious Minotaur which was confined in that place, and which usually fed upon the chosen young men and maidens exacted from the Athenians as a yearly tribute to the tyranny of Minos, but Theseus slew the monster, and being furnished with a clue of thread by Ariadne, who was passionately enamoured of him, he extricated himself from the difficult windings of his confinement.
He afterwards married the beautiful Ariadne, according to promise, and carried her away; but when he arrived at the island of Naxos, he deserted her, notwithstanding he had received from her the most honourable evidence of attachment and endearing tenderness. Ariadne was so disconsolate upon being abandoned by Theseus, that, as some say, she hanged herself; but Plutarch says that she lived many years after, and was espoused to Bacchus, who loved her with much tenderness, and gave her a crown of seven stars, which, after her death, was placed among the stars.
"Resolves, for this the dear engaging dame
The golden circlet mounts; and, as it flies,
There, in their pristine form, the gemmy rays
Manilius, in the first book of his Astronomicon, thus speaks of the Crown. "Near to Bootes the bright crown is view'd
And shines with stars of different magnitude:
Where is it situated? Describe the principal star in the group. What geometrical figure is formed by the stars in this neighbourhood? What are the number and magnitude of the stars in this constellation? What are its mean declination and right ascension? When is it on cur meridian?
Or placed in front above the rest displays
THE LITTLE BEAR.-This constellation, though not remarkable in its appearance, and containing but few conspicuous stars, is, nevertheless, justly distinguished from all others for the peculiar advantages which its position in the neavens is well known to afford to nautical astronomy, and especially to navigation and surveying.
The stars in this group being situated near the celestial pole, appear to revolve about it, very slowly, and in circles so small as never to descend below the horizon.
In all ages of the world, this constellation has been more universally observed, and more carefully noticed than any other, on account of the importance which mankind early attached to the position of its principal star.
This star which is so near the true pole of the heavens, has, from time immemorial, been denominated the NORTH POLAR STAR. By the Greeks it is called Cynosyre; by the Romans, Cynosura, and by other nations, Alruccabah.
It is of the 3d magnitude, or between the 2d and 3d, and situated a little more than a degree and a half from the true pole of the heavens, on that side of it which is towards Cassiopeia, and opposite to Ursa Major. Its position is pointed out by the direction of the two Pointers, Merak and Dubhe, which lie in the square of Ursa Major. A line joining Beta Cassiopeia, which lies at the distance of 32° on one side, and Megrez, which lies at the same distance on the other, will pass through the polar star.
So general is the popular notion, that the North Polar Star is the true pole of the world, that even surveyors and navigators, who have acquired considerable dexterity in the use of the compass and the quadrant, are not aware that it ever had any deviation, and consequently never make allowance for any. All calculations derived from the observed position of this star, which are founded upon the idea that its bearing is always due north of any place, are necessarily erroneous, since it is in this position only twice in twenty-four hours; once when above, and once when below the pole.
What renders Ursa Minor an important constellation? What is its situation with respect to the North Pole, and how do its stars appear to revolve around this pole? Why has this constellation been more universally observed, in all ages of the world, than any other? What is this star denominated? What are its magnitude and position? How is its position pointed out? How is it situated with respect to Megrez and Beta Cassiopefæ? Is it generally considered to be the north pole of the heavens ? Are calculations founded upon this notion correct?