"Yes, we can see them all the year round, just as we can always see the Pole Star and the Great Dipper. The Royal Family consists of King Cepheus, Queen Cassiopeia, and her daughter Andromeda, sometimes called the 'Chained Lady.' Perseus, the rescuer, is at the feet of Andromeda, while her head rests upon the shoulder of the winged horse Pegasus. "The Grecians told a wonderful story about this family. It appears that Cassiopeia boasted of her beauty, and said she was more attractive than Juno, the wife of Jupiter. As for her daughter Andromeda, not a nymph in the sea could compare with her in good looks. You may imagine how Juno and the sea-nymphs felt when they heard this vain boast! "They determined to have revenge, and Juno asked Jupiter to punish Cassiopeia. So she was sent away from the earth and placed among the stars with her husband Cepheus. [Illustration: KING CEPHEUS.] "As for Andromeda, the sea-nymphs asked Neptune to send a sea-monster to devour her. She was chained to a rock so that she might not escape this terrible fate; but just as the monster was approaching a brave hero named Perseus came to her rescue. [Illustration: THE FAIR ANDROMEDE.] "Perseus was returning through the air on his winged horse Pegasus from a terrible encounter with the Gorgons. These were three sisters who frightened everyone that saw them. Serpents were wreathed around their heads instead of hair, their hands were of brass, their bodies were covered with scales, and their eyes had the power of turning all they looked at to stone. Perseus had cut off the heads of one of these terrible beings, and when he saw the monster approaching Andromeda, he turned the head which he still held in his hand toward it, and in a moment it turned to stone. "As a reward for his bravery, he was placed after his death among the stars, and near the fair Andromeda. He still holds the head in his hand, and a star named Algol, or the Demon, as the Arabs call it, marks the evil eye. Sometimes it is bright, but in a few hours it will grow dim, as though winking at the people on earth. For this reason it is called a variable or changing star." [Illustration: PERSEUS.] "What is that, sister?" asked Harry. "A star that is brighter one time than another. Supposing someone kept turning the wick of the lamp up and down so that at one moment the room would be very bright and the next moment quite dim. You would call that a changing light. So it is with these stars, only in the case of Algol it is a planet that goes around it and at times cuts off part of its light. For two days and a half it is very bright, then during three or four hours it begins to get dim, and remains so for twenty minutes and then it gets bright again.