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THE CELESTIAL MOTIONS

away from the star, being nearly two diameters distant from it. The figure shows how this would go on at the time of the spring equinox, after March twentieth. This motion would continue month after month. At the end

Fig. 4.—The Sun Crossing the Equator about March Twentieth.

of the year the sun would have made a complete circuit of the heavens relative to the star, and we should see the two once more together.

The Sun's Apparent Path

How the above effect is produced will be seen by Figure 5, which represents the earth's orbit round the sun, with the stars in the vast distance. When the earth is at A, we see the sun in the line AM, as if it were among the stars at M. As we are carried on the earth from A to B, the sun seems to move from M to N, and so on through the year. This apparent motion of the sun in one year around the celestial sphere, was noticed by the ancients, who seem to have taken much trouble to map it out. They

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