Stránka:roll 1916.djvu/322

apS Woodcraft Maaual for Girls The Great Bear is also to be remembered as the hour-hand of the woodman's clock. It goes once around the North Star in about twenty-four hours, the same way as the sun, and for the same reason — that it is the earth that is going and leaving them behind. The time in going around is not exactly twenty-four hours, so that the position of the Pointers varies with the seasons, but, as a rule, this for woodcraft purposes is near enough. The bowl of the Dipper swings four-fifths of the width of its own opening in one hour. If it went a quarter of the curcle, that would mean you had slept a quarter of a day, or six hours. Every fifteen days the stars seem to be an hour earUer; in three months they gain one-fourth of the circle, and in a year gain the whole circle. According to Flammarion, there are about seven thousand stars visible to the naked eye, and of these twenty are stars of the first magnitude. Fourteen of them are visible in the latitude of New York, the others (those starred) belong to the South Polar region of the sky. The following table of the brightest stars is taken from the Revised Harvard Photometry of 1908, the best authority on the subject. The First Twenty Stars in Order of Brightness 1. Sirius, the Dog Star. 2. *Canopus, of the Ship. 3. *Alpha, of the Centaur. 4. Vega, of the Lyre. 5. Capella, of the Charioteer. 6. Arcturus, of the Herdsman. 7. Rigel, of Orion. 8. Procyon, the Little Dog-star. 9. *Achemar, of Eridanus. 10. *Beta, of the Centaur. 1 1 . Ahair, of the Eagle. 12. Betelgeuze, of Orion's right shoulder. 13. *Alpha, of the Southern Cross. 14. Aldebaran, of the Bull's right eye. 15. Pollux, of the Twins. 16. Spica, of the Virgin. 17. Antares, of the Scorpion. 18. Fomalhaut, of the Southern Fish. 19. Deneb, of the Swan. ao, Regulus, of the