Dante and the early astronomers . sun is nota mere lagging behind the stars, for his west to eastmotion is combined with a north and south we note the star-groups which are just behind himwhen he sets (or just before him when he rises), weshall find that they form a great circle round the globe,half of which lies north and half south of the celestialequator. The Greeks named this circle the Zodiac, orPath of the Animals, because the star-groups formingit were mostly called by the names of animals (theRam, Lion, Fishes, etc.). When the sun is in the mostnortherly part of the zodiac it
Dante and the early astronomers . sun is nota mere lagging behind the stars, for his west to eastmotion is combined with a north and south we note the star-groups which are just behind himwhen he sets (or just before him when he rises), weshall find that they form a great circle round the globe,half of which lies north and half south of the celestialequator. The Greeks named this circle the Zodiac, orPath of the Animals, because the star-groups formingit were mostly called by the names of animals (theRam, Lion, Fishes, etc.). When the sun is in the mostnortherly part of the zodiac it is summer in the THE HEAVENLY BODIES. 11 northern hemisphere; when he is in the most southerly,it is summer in the south. (See Map). This north and south motion of the sun may benoted more directly in another way. Seen from anygiven place on the earth, each star rises and sets atthe same points of the horizon always, and has thesame course in the sky; but the rising and settingpoints of the sun, which on about the 21st of March. Fig. 1. The Suns path in the slcy at difFereut seasons. are due east and west, travel daily further north, andthe sun mounts daily higher in northern skies untilabout the 20th of June; then he returns towards thesouth, passing the east and west points again aboutSeptember 23, and reaches his furthest point southabout December 21. (The dates vary slightly owing toLeap Year). The dates on which the sun reaches hisfurthest north and furthest south points in this yearlyjourney are called the solstices, because his motionseems to be checked, and he pauses or stands before 12 APPARENT MOVEMENTS OF reversing his direction; the dates on which he passesthe midway point are the equinoxes, because at thosepoints he is on the equator, and makes day and nightequal all over the earth. The time taken by the sun to pass from one vernal(spring) equinox to another is 365 days, 5 hours,48 minutes, 45 seconds. Since this slow motion alongthe zodiac is from west to east, c
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