2. 6 CANIS MINURIS (Gomelsa)-A wide TRIPLE STAR in theneck; R. A. Th. 18m. 28s Dec. N. 8' 86' 4". A 3, white; B 12, orange; C 10, flushed-the last coarsely double with one of the same magnitude. Other stars in the field. 3. A close DOUBLE STAR, in a fine vicinity in the loins; R. A. 7h. 81m. 87s.; Dec. N. 5° 85' 7". A 7, white; B 8, ash-colored, with a minute blue star 2' distant. 4. A WIDE TRIPLE STAR, 6° S. E. of Procyon; R. A. 7h. 50m. 03s.; Dec. N. 2" 88' 8". A 6, pale white; B 8, bluish; C 9, blue. MONOCEROS (THE UNICORN).—MAP III. 101. This is a modern constellation, made out of the unformed stars of the ancients that lay scattered over a large space of the heavens between the two Dogs. It extends a considerable distance on each side of the equinoctial, and its centre is on the same meridian with Procyon. 102. It contains 31 small stars, of which the seven principal ones are of only the 4th magnitude. Three of these are situated in the head, 3° or 4° apart, forming a straight line N. E. and S. W. about 9° E. of Betelguese in Orion's shoulder, and about the same distance S. of Albena in the foot of the twins. The remaining stars in this constellation are scattered over a large space, and being very small, are unworthy of particular notice. HISTORY. The Monoceros is a species of the Unicorn or Rhinoceros. It is about the size of a horse, with one white horn growing out of the middle of its forehead. It is said to exist in the wilds of Ethiopia, and to be very formidable. Naturalists say that, when pursued by the hunters, it precipitates itself from the tops of the highest rocks, and pitches upon its horn, which sustains the whole force of its fall, so that it receives no damage thereby. Sparmann informs us, that the figure of the unicorn, described by some of the ancients, has been found delineated on the surface of a rock in Caffraria; and thence conjectures that such an animal, instead of being fabulous, as some suppose, did once actually exist in Africa. Lobo affirms that he has seen it. The rhinoceros, which is akin to it, is found in Bengal, Siam, Cochin China, part of China Proper, and the isles of Java and Sumatra. TELESCOPIC OBJECTS. 1. A most delicate DOUBLE STAR (ƒ), in the Unicorn's eye; R. A. 6h. 26m. 06s.; Dec. N. 7° 41′ 05′′. A 6, yellowish white: B 16, dusky. A difficult object. 2. A neat DOUBLE STAR (b), in the nostril, 7° east of Betelguese; R. A. 6h. 15m. 17s.; Dec. N. 4° 40' 01". A 5%, golden yellow; B 8, lilac. 3. A fine TRIPLE STAR in the right fore-leg; R. A. 6h. 21m. 04s.; Dec. S. 6° 56′ 01′′. A 6%, white; B7, and C 8, both pale white. A ray shot from the Bull's eye through Bellatrix, and rather more than as far again, will pick it up. Supposed by Herschel to be a triple system, periods A B 17,000 ys. B C 1000. Shown double only on the map of the constellations. Telescopic view, Map VIII., Fig. 5. 4. A delicate TRIPLE STAR, in a magnificent stellar field, between the Unicorn's ears. R. A. 6h. 82m. 10s.; Dec. N. 10° 02' 02". One-third the distance from Procyon to Ahlebaran. A 6, greenish; B 9%, pale grey; C 15, blue. A fine object. 101. Character and situation of Monoceros? Extent? stars? How three of the largest situated? 102. Number and size of its HISTORY.-What said of the animal itself? Is it not wholly fabulous? CANIS MAJOR (THE GREAT DOG).—MAP III. 103. This interesting constellation is situated southward and eastward of Orion, and is universally known by the brilliance of its principal star, Sirius, which is apparently the largest and brightest in the heavens. It glows in the winter hemisphere with a lustre which is unequaled by any other star in the firmament. Its distance from the earth, though computed at 20 millions of millions of miles, is supposed to be less than that of any other star: a distance, however, so great that a cannon ball, which flies at the rate of 19 miles a minute, would be two millions of years in passing over the mighty interval; while sound, moving at the rate of 13 miles a minute, would reach Sirius in little less than three millions of years. It may be shown in the same manner, that a ray of light, which occupies only 8 minutes and 13 seconds in coming to us from the sun, which is at the rate of nearly two hundred thousand miles a second, would be 3 years and 82 days in passing through the vast space that lies between Sirius and the earth. Consequently, were it blotted from the heavens, its light would continue visible to us for a period of 8 years and 82 days after it had ceased to be. If the nearest stars give such astonishing results, what shall we say of those which are situated a thousand times as far beyond these, as these are from us? 104. In the remote ages of the world, when every man was his own astronomer, the rising and setting of Sirius, or the Dog Star, as it is called, was watched with deep and various solicitude. The ancient Thebans, who first cultivated astronomy in Egypt, determined the length of the year by the number of its risings. The Egyptians watched its rising with mingled apprehensions of hope and fear; as it was ominous to them of agricultural prosperity or blighting drought. It foretold to them the rising of the Nile, which they called Siris, and admonished them when to sow. 105. The Romans were accustomed yearly to sacrifice a dog to Sirius, to render him propitious in his influence upon their herds and fields. The eastern nations generally believed the rising of Sirius would be productive of great heat on the earth. Thus Virgil: "Tum steriles exurere Sirius agros; Ardebant herbæ, et victum seges ægra negabat." -"Parched was the grass, and blighted was the corn: Supposed distance of Sirius? Illus104. How was Sirius regarded by the The Egyptians? 105. Practice of the 108. Situation of Canis Major? How known? trated by the speed of a cannon ball? Of light? ancients? Use made of it by the Thebans ? Roans? 106. Accordingly, to that season of the year when Sirius rose with the sun and seemed to blend its own influence with the beat of that luminary, the ancients gave the name of Dog-days, (Dies canicularis.) At that remote period the Dog-days commenced on the 4th of August, or four days after the summer solstice, and lasted forty days, or until the 14th of September. At present the dog-days begin on the 3d of July, and continue to the 11th of August, being one day less than the ancients reckoned. 107. Hence, it is plain that the Dog-days of the moderns have no reference whatever to the rising of Sirius, or any other star, because the time of their rising is perpetually accelerated by the precession of the equinoxes: they have reference then only to the summer solstice, which never changes its position in respect to the seasons. The time of Sirius' rising varies with the latitude of the place, and in the same latitude, is sensibly changed after a course of years, on account of the precession of the equinoxes. This enables us to determine with approximate accuracy, the dates of many events of antiquity, which cannot be well determined by other records. We do not know, for instance, in what precise period of the world Hesiod flourished. Yet he tells us in his Opera et Dies, lib. ii. v. 185, that Arcturus in his time rose heliacally, 60 days after the winter solstice, which then was in the 9th degree of Aquarius, or 39° beyond its present position. Now 39°: 50%=2794 years since the time of Hesiod, which corresponds very nearly with history. 108. When a star rose at sun-setting, or set at sun-rising, it was called the Achronical rising or setting. When a planet or star appeared above the horizon just before the sun, in the morning, it was called the Heliacal rising of the star ; and when it sunk below the horizon immediately after the sun, in the evening, it was called the Heliacal setting. According to Ptolemy, stars of the first magnitude are seen rising and setting when the sun is 12 below the horizon; stars of the 2a magnitude require the sun's depression to be 13°; stars of the 3d magnitude, 14', and so on, allowing one degree for each magnitude. The rising and setting of the stars described in this way, since this mode of description often occurs in Hesiod, Virgil, Columella, Ovid, Pliny, &c., are called poctival rising and setting. They served to mark the times of religious ceremonies, the seasons allotted to the several departments of husbandry, and the overflowing of the Nile. 109. The student may be perplexed to understand how the Dog Star, which he seldom sees till mid-winter, should be associated with the most fervid heat of summer. This is explained by considering that this star, in summer, is over our heads in the daytime, and in the lower hemisphere at night. As "thick the floor of heaven is inlaid with patines of bright gold," by day, 106. Origin of the phrase Dog-days? When did they begin in the time of Virgil? At what time now? 107. What inference from these facts? What variation in the time of Sirius' rising? What calculation by knowing the time when Sirius rose, at any period! 105. What are the Achronical and Heliacal rising or setting of a star or planet? Re mark of Ptolemy in regard to rising and setting of the stars? 109. How is it that Birius a winter star, is associated with the heat of summer? as by night; but on account of the superior splendor of the sun, we cannot see them. 110 Sirius is situated nearly S. of Alhena, in the feet of the Twins, and about as far S. of the equinoctial as Alhena is N. of it. It is about 10° E. of the Hare, and 26° S. of Betel. guese in Orion, with which it forms a large equilateral triangle. It also forms a similar triangle with Phaet in the Dove, and Naos in the Ship. These two triangles being joined at their vertex in Sirius, present the figure of an enormous X, called by some, the EGYPTIAN X. Sirius is also pointed out by the direction of the Three Stars in the belt of Orion. Its distance from them is about 23°. It comes to the meridian at 9 o'clock on the 11th of February. 111. Mirzam, in the foot of the Dog, is a star of the 2d magnitude, 51° W. of Sirius. A little above, and 4° or 5° to the left, there are three stars of the 3d and 4th magnitudes, forming a triangular figure somewhat resembling a dog's head. The brightest of them, on the left, is called Muliphen. It entirely disappeared in 1670, and was not seen again for more than 20 years. Since that time it has maintained a steady lustre. 112. Wesen is a star of between the 2d and 3d magnitudes, in the back, 11° S. S. E. of Sirius, with which, and Mirzam in the paw, it makes an elongated triangle. The two hinder feet are marked by Naos and Lambda, stars of the 3d and 4th magnitudes, situated about 3° apart, and 12° directly S. of the fore foot. This constellation contains 31 visible stars, including one of the 1st magnitude, four of the 2d, and two of the 3d; all of which are easily traced out by the aid of the map. HISTORY. Manilius, a Latin poet who flourished in the Augustan age, wrote an admirable poem, five books, upon the fixed star, in which he thus speaks of this constellation: "All others he excels; no fairer light Ascends the skies, none sets so clear and bright.” bu: EUDOSIA best describes it "Next shines the Dog with sixty-four distinct; According to some mythologists, this constellation represents one of Orion's hounds, crich was placed in the sky, near this celebrated huntsman. Others say it received its eme in boner of the dog given by Aurora to Cephalus, which surpassed in speed all the 110. Situ ber of Sirius? What triangles ? 111. Position and size of Mirzam! ther start? Gf'u hen? 112. Wesen? What other stars? Whole number? HISTORY.--Baassical description of Canis Major? What different accounts of its rigin ? animals of his species. Cephalus, it is said, attempted to prove this by running him against a fox, which, at that time, was thought to be the fleetest of all animals. After they had run together a long time, without either of them obtaining the victory, it is said that Jupiter was so much gratified at the fleetness of the dog, that he assigned him a place in the heavens. But the name and form of this constellation are, no doubt, derived from the Egyp tians, who carefully watched its rising, and by it judged of the swelling of the Nile, which they ca.ied Siris, and, in their hieroglyphical manner of writing, since it was, as it were, the sentinel and watch of the year, represented it under the figure of a dog. They observed that when Sirius became visible in the east, just before the morning dawn, the overflowing of the Nile immediately followed. Thus it warned them, like a faithful dog, to escape from the region of the inundation. TELESCOPIC OBJECTS, 1, a CANIS MAJORIS-A brilliant star, with a distant companion; R. A. 6h. 88m. 06s.; Dec. S. 16° 30′ 1. A 1, brilliant white; B 10, deep yellow, other distant small stars in the field. 2. CANIS MAJORIS-A star with a distant companion in the loins; R. A. 7h. 01m. 53s.; Dec, S. 26° 08' 6". A 8, light yellow; B 7%, very pale. Other small stars in the field, A line from Betelguese through Sirius intercepts it 12° below the latter star. 8. & CANIS MAJORIS (Adhara)-A star with a distant companion in the belly; R. A 6h. 52m. 20s. Dec. S. 28° 45′ 5′′. A 2%1⁄2, pale orange: B 7, violet. Found by running a line from the middle of Orion's belt through ẞ just west of Sirius, to about 14° beyond the latter star. 4. A CLUSTER in the back of the head; R. A. 6h. 52m. 10s.; Dec. S. 13° 29' 2". Tolerably compressed; stars of the 8th to 11th magnitudes, of which the four principal form the letter Y. 5. A CLUSTER between Sirius and Monoceros; R. A. 7h. 10m. 35s.; Dec. 8. 15° 21′ 4′′ Stars principally of the 10th magnitude. Discovered by Miss Herschel in 1785. CHAPTER V. CONSTELLATIONS ON THE MERIDIAN IN MARCH. ARGO NAVIS (THE SHIP ARGO).—MAP III. 113. THIS Constellation occupies a large space in the southern hemisphere, though but a small part of it can be seen in the United States. It is situated S. E. of Canis Major, and may be known by the stars in the prow and deck of the ship. 114. If a straight line joining Betelguese and Sirius, be produced 18° to the southeast, it will point out Naos, a star of the 2d magnitude, in the rowlock of the ship. This star is in the S. E. corner of the Egyptian X, and of the large equilateral triangle made by itself with Sirius and the Dove. When on the meridian, it is seen from this latitude about 8° above the south TELESCOPIC OBJECTS.-Alpha? Delta? Epsilon? What clusters? 118. Size and situation of Argo Navis? How known? 114. How hnd Nave, Bud where situated? How high when on the meridian? |