“Well,” said Peter briskly, “what do we find to-night, Uncle Hen?”
“We’ll begin,” replied Uncle Henry, “with a person you may have heard of—Perseus, who killed the terrible Gorgon Medusa.”
“Oh, I know him,” cried Paul, “we read all ’bout him last year.”
“Quite right,” said Uncle Henry, “then you remember that when he had killed Medusa, and cut off her head with his sword, he had to hold the head with the terrible face away from him, because everybody who looked at that face was instantly turned to stone.”
“Yes, yes, we know!” chorused the Society.
“Well, now we’ll find Perseus, his sword, and the head of Medusa,” promised Uncle Henry. “All you have to do is to extend the line of Andromeda’s left leg and prolong it from her foot, straight out for about her whole length. ([30]) There you will find Algenib, the brightest star in Perseus. It is right in his neck, between his shoulders. From Algenib you can trace a row of stars downward, almost to the Pleiades in the bull’s shoulder. This row of stars is Perseus’ body and legs. Then find two stars above Algenib, one over the other, and you have his head and helmet.
“After that it is easy to start at Algenib and trace out his right arm, with the sword. A line drawn toward Perseus through the stars in Andromeda’s head and left hip points out the star Algol, which is the head of Medusa, held in Perseus’ left hand. ([31]) Algol is a famous variable star, which the ancients named ‘the dragon of the slowly winking eye.’”
The children soon found all of Perseus, and all took part in drawing his skeleton on the blackboard. Then they watched Algol in the sky, and expected to see it wink, until Uncle Henry told them that the wink is so slow that it takes seven hours for Algol to become faint and bright again, and that then two and three-quarter days pass before Algol winks again. This being the case the Society decided not to wait, and finished Perseus up so that he looked this way:
