Dante and the early astronomers . aremuch more easily observed than those of the sun,since we can see the stars at the same time, and herrevolution is much more rapid. She also is apparentlycarried round with the daily east to west movement,and she also has a west to east motion of her own, butso fast that it takes her round the star-sphere in onemonth, instead of one year. This revolution also takesplace in the zodiac. She is first visible as a finecrescent, just following the sun, in the west, after he ^ Greek gnomon, an interpreter. A pole set up in order to show thelength of shadow thrown
Dante and the early astronomers . aremuch more easily observed than those of the sun,since we can see the stars at the same time, and herrevolution is much more rapid. She also is apparentlycarried round with the daily east to west movement,and she also has a west to east motion of her own, butso fast that it takes her round the star-sphere in onemonth, instead of one year. This revolution also takesplace in the zodiac. She is first visible as a finecrescent, just following the sun, in the west, after he ^ Greek gnomon, an interpreter. A pole set up in order to show thelength of shadow thrown by the sun. 14 APPARENT MOVEMENTS OF has set; next night she is markedly further from thesun, on her eastward course, and is a larger crescent;she continues increasing her distance from the sun andthe size of her disc, until, as full moon, she is risingin the east when the sun sets opposite her in the west,and setting when the sun rises. After this, she beginsto wane, and, still travelling in the same direction, ^ Three da^s old. One day old ^ \ \ Fig. 2. The Moon at Sunset. rij^es later and later at night, and sets in the day; shedraws gradually nearer to the sun on the western side,till at last, as a fine crescent with the horns turned inthe other direction { always away from the sun),she appears just before the rising sun in the for a short time she is lost in his rays, tillshe emerges as a new moon on the sunset sideaofain. The moon completes a revolution among the stars in27 days, 8 hours; but it takes her a little longer tocome up with the sun again, since he has meanwhilebeen moving in the same direction along his yearly THE HEAVENLY BODIES. 15 path; and the synodic month, or period from one new-moon to the next, is 29 days, 13 hours. As well as the moving sun and the moving moon,there are ^we other bodies, visible to the naked eye,which move among the stars. They look like stars,but their movements would lead us rather to classthem with sun and moon. They
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