"Supposing you were trying to read by lamplight, and I should now and then hold a book between the lamp and you. Each time I did so the light on your book would grow dim. There is another variable or changing star named Mira, in the group of stars called Cetus, which is no other than the sea-monster which was sent to devour Andromeda. You can see it if you look out of the window facing south, and you will notice that it is at a safe distance from Andromeda, who is almost exactly overhead just now." STORY OF THE FISHES. "Not far from the sea-monster are the Fishes, and the story about them is as follows: "One day when Venus and her little son Cupid were walking beside the banks of a river they were frightened at seeing a terrible giant named Typhon. Flames flashed from his eyes, and as he glared at Venus and Cupid they were overcome with fear and called on Jupiter to help them. He changed them into fishes, and afterward placed them among the stars. "Between Cetus and Orion you can see some stars winding in and out, and they are part of the River Eridanus. A daring youth named Phaeton tried to drive the chariot of the sun through the sky one day. Jupiter struck him with a thunderbolt, and hurled him from heaven into the river below. [Illustration: RIVER ERIDANUS.] "'At once from life and from the chariot driven, Th' ambitious boy fell thunderstruck from heaven. * * * * * The breathless Phaeton, with flaming hair, Shot from the chariot like a falling star That in a summer's evening from the top Of heaven drops down, or seems at least to drop.' "His sisters mourned his unhappy end, and were changed by Jupiter into poplars, which are still to be seen on the banks of the River Eridanus. "'All the night long their mournful watch they keep, And all the day stand round the tomb and weep.'" "Poor Phaeton," said Harry, as Mary finished the story. "And is that Phaeton with those three bright stars near the river?" [Illustration: CLOUD OF STAR-MIST IN ORION.] "No; that is Orion," replied his sister, "and the three bright stars mark his belt. Under it you can see a small cloud of mist, if you look at it through your opera glass. It is clinging around one of the faint stars in the sword. This is star-mist, from which other stars are being made, and it looks small only because it is so far away from us; but there is enough star-dust there to make thousands of bright stars. Astronomers called these clouds nebulæ." "Who was Orion?" asked Harry. "Won't you tell me more about him?" "He was a mighty hunter, and in the old maps you can see him represented as warding off the attack of the Bull, which is glaring at him with its bright red eye named Aldebaran. A story was told by the Grecians about this bull: