Hesiod mentions (' Opera et Dies ') the Pleiades, Arcturus, and Orion, stating that land should be ploughed at the heliacal setting, and corn reaped at the heliacal rising of the Pleiades (about the middle of April); he directs also that corn should he threshed at the rising of Orion, and vines pruned when Arcturus rises in the evening. Homer also mentions the Pleiades, Hyades, the Bear or Waggon, dpKTOY 644ataY br[KAnCrlY ualdooaly, and Orion in the description of the shield of Achilles (' IL,' xviii., 487); it is evident therefore that already in the time of Homer those constel lations were introduced in the sphere of the Greeks. Plutarch asserts that Anaximander (probably about 600 me.) constructed a dial ; and that representations of the clusters of stars, together with figures of the constellations, were frequently executed in Greece in the time of Hipparchus, is evident from a passage in the commentary of that astronomer on the poem of Amtus planispheres, he observes, are con structed for men's use, and' therefore the figures on them are traced just as they appear in the heavens to the view of the spectator.
In the work of Autolycus, entitled On Risings and Settings' of the Stars (rep! Kat Aliacaw), and in the Phrenornena ' of Euclid, the signs of the zodiac are mentioned, and the parts into which that band of the heavens was divided are called dodecatemories, or twelfths ; but it is in the astronomical poem of Aratua that the most complete knowledge of the celestial sphere of the Greeks is to be ob tained. This writer lived about 270 years before the Christian era, and his poem is a paraphrase of two works which were composed by Eudoxus of Cnidue, who lived 100 years previously, that is, in the age of Autolycus and Euclid.
In describing the constellations, Aratus begins with those imme diately about the north pole of the equator, and proceeds from thence to the zodiac, nearly in the directions of the declination or hour-circles of the sphere. He mentions Ursa Major and Ursa Minor, observing that they are placed so that the tail of one corresponds to the shoulders of the other, and he adds that the constellation Draco winds between them. Near the head of Draco he places the figure of a man, who is said to be on his knees (Hercules, whose attitude has since been changed), and behind him the northern crown. Near the kneeling figure is Ophiuchus, the serpent-carrier, and under the latter are the great claws (of Scorpio). Behind Urea Major is Arctophylax (Bootes), with the star Arcturus below his girdle ; and under his feet is the con stellation Virgo. Near the head of Ursa Major are Gemini (Afautrot); under his body is Cancer, and under his feet Leo. Auriga and the star Capella are said to be on the left of Gemini, opposite Ursa Major ; and at the foot of Auriga are the horns of Taurus, whose head is indi cated by a cluster of stars (the Hyades). Cepheus is behind Ursa
Minor, aw! :1:ar him is Cassiopeia, the stars of which are said to be arranged in the form of a key : Cassiopeia has her hands raised above her head as if bewailing the fate of her daughter Andromeda, who is placed below her. The arms of the latter are extended and chained (to a rock); and under her head is Pegasus. Aries is below the girdle of Andromeda, and, as well as the claws of Scorpio and the girdle of Orion, it is in the equator ; the triangle (Stavorrbv) is above Aries. The oonstellation Pisces is below the triangle ; and Perseus stands with his hand near the chair of Cassiopeia. Below his left knee are the Pleiades, and the names of the seven daughters of Atlas are given to the stars of the cluster. Aratus observes that there are but ,ix stars in the cluster ; but Itipparchus, in his commentary on the poem, states that against a dark sky seven may be seen. The bow of Sagits farina tends towards the tail of Scorpio. The Lyre, and the eagle which carries it, is between Perseus and the head of the bird (Spas). (This' is the constellation Cygnus, which also by Manetho and Ptolemy is called the Bird. The name Cygnus is first applied to it in a work on the constellations which is ascribed to Eratosthenea.) Cygnus extends towards the other eagle (Aquila), and near the head of Pegasus is the right hand of Aquarius, which, it is:remarked, rises before Capri comm. Over the latter is the Dolphin. All the above constellations are stated to be between tbe zodiac and the north pole ; and the zodiacal constellations are afterwards mentioned in order, beginning with Cancer and ending with Gemini. Libra (elsewhere called {u760 is not mentioned, while Scorpio and the Claws are described as if they formed two constellations.
In the description of the constellations between tbe zodiac and the south pole, it is stated that Orion is placed obliquely to Taurus, and that Canis Major is at his feet. Under him ie said to be Lepus, and at the tail of the dog is the head of the ship Argo. Under Aries and Pisces, and above the river (Eridanus), Cetus advances towards Andro meda, and below Capricornus is the Southern Fish. Under Sagittarius is a circle of stars (the Southern Crown), and below the sting of Scorpio is the Altar. Under the Scorpion is Centaurus, while farther on is Hydra, having its head under Cancer, and its tail above Centaurus : about the middle of its body is Craterus, and near the tail is Corvus. The bright star Procyon is under Gemini.