time, Cadmus, weary of his wanderings, inquired of the oracle of Apollo concerning the fate of Europa. He was told to cease looking for his sister, to follow a cow as a guide, and when she rested, there to build a city. Hardly had Cadmus stepped out of the temple, when he saw a cow slowly walking along. He followed her until she came upon the broad plains where Thebes afterward stood. Here she stopped. Cadmus wishing to offer a sacrifice to Jupiter in gratitude for the delightful location, sent his servants to seek for water. In a dense grove near by was a fountain guarded by a fierce dragon (DRACO), and sacred to Mars. The Tyrians approaching this and attempting to dip up some water, were attacked, and many of them killed by that enormous serpent, whose head overtopped the tallest trees. Cadmus, becoming impatient, went in search of his men, and on coming to the spring, saw the sad disaster. He forthwith fell upon the monster, and after a severe battle succeeded in slaying him. While standing over his conquered foe, he heard a voice from the ground bidding him take the dragon's teeth and sow them. He obeyed. Scarcely had he finished ere the earth began to move and the points of spears to prick through the surface. Next nodding plumes shook off the clods, and the heads of armed men protruded. Soon a great harvest of warriors covered the entire plain. Cadmus, in terror at the appearance of these giants, whom he termed Sparti (the Sown), prepared to attack them, when suddenly they

turned upon themselves, and never ceased their warfare until only five of the crowd survived. These making peace with each other, joined Cadmus and assisted him in building the city of Thebes.

Cepheus is represented as a king in regal state, with a crown of stars on his head, while he holds in his hand a sceptre which is extended toward his wife, Cassiopeia. The constellation contains thirtyfive stars visible to the naked eye.

Principal stars.-The brightest star is Alderamin (a), in the right shoulder. Alphirk (6), in the girdle, is at the common vertex of several triangles, which point out respectively the left shoulder (1), the left knee (7), and the right foot. The head, which lies in the Milky Way, is marked by a delicate little triangle of three stars. This forms, with a, B, and, quite a regular quadrilateral figure. A bright little star of the fifth magnitude, close to Polaris, points. out the left foot.

Cassiopeia* is represented as a queen seated on her throne. On her right is the king, on her left Perseus, her son-in-law, and above her is Andromeda, her daughter. The constellation contains fiftyfive stars visible to the naked eye.

Principal stars.-A line drawn from Megrez (§), in Ursa Major, through Polaris and continued an equal distance beyond, will strike Caph (8) in Cassiopeia. This star is noticeable as marking, with the others

* For mythological history, see Perseus and Andromeda.

named, the equinoctial colure, and as being on the same side of the true pole as Polaris. The principal stars form the figure of an inverted chair, which is very striking and may be easily traced..

EQUATORIAL CONSTELLATIONS.

The constellations we shall now describe lie south of the circumpolar groups. Only a portion of their paths is above our horizon. In using the maps, the observer is supposed to stand with his back toward Polaris, and to be looking directly south. Commencing with the constellation Perseus, so intimately connected with the other members of the royal family just described, we pass eastward in our survey and notice the various constellations as they slowly defile in silent march across the sky. The first map represents the constellations on or near the meridian at nine o'clock in the evening of the winter solstice. On the evening of the autumnal equinox, the lefthand side of the map should be turned downward toward the eastern horizon. On the evening of the vernal equinox, the right-hand side should be turned to the western horizon. At these different times, the stars, though preserving their relative positions, will be diversely inclined to the horizon. As the stars apparently move westward at the rate of 15° per hour, the time of the evening determines what stars will be visible, and also their distances above the horizon.

Perseus is represented as brandishing an enormous sword in his right hand, while in his left he holds the head of Medusa. The constellation comprises eighty-one stars visible to the naked eye.

Principal stars.-The most prominent figure is called the segment of Perseus. It consists of several stars arranged in a line curving toward Ursa Major. Algenib (a), the brightest of these, is of the second magnitude. Algol, in the midst of a group of small stars, marks the head of Medusa. Between the bright stars of Perseus and Cassiopeia is a beautiful star-cluster visible to the naked eye.

Mythological history.--Perseus, from whom this constellation was named, was the son of Jupiter and Danäe. His grandfather, Acrisius, having been informed by the oracle that his grandson would be the

instrument of his death, put the mother and child in a coffer and set them adrift on the sea. Fortunately, they floated near the island Seriphus, where they were rescued and kindly treated by a brother of Polydectes, king of the country. When Perseus had grown up, he was ordered by Polydectes to bring him, as a marriage gift, the head of Medusa. Now Medusa was once a beautiful maiden, who dared to compare her ringlets with those of Minerva; whereupon the goddess changed her locks into hissing serpents, and made her features so hideous, that she turned to stone every living object upon which she fixed her Gorgon gaze. Perseus was at first quite overpowered at the thought of undertaking this enterprise, but was visited by Mercury, who promised to be his guide, and to furnish him with his winged shoes. Minerva loaned him her wonderful shield, that was bright as a mirror. The Nymphs gave him, in addition, Pluto's helmet, which made the bearer invisible. Thus equipped, Perseus mounted into the air and flew to the ocean, where he found the three Gorgons, of whom Medusa was one, asleep. Fearing to gaze in her face, he looked upon the image reflected in Minerva's shield, and with his sword severed Medusa's head from her body. The blood gushed forth, and with it the winged steed PEGASUS. Grasping the head, Perseus flew away. The other Gorgons awaking, pursued him, but he escaped their search by means of Pluto's helmet. Flying over the wilds of Libya, in his aerial route, drops dripping