ZODIAC. 



1854, was at the points c and o on the 20th of March and 

 the 23rd of September, so that it moved from c through 

 o to c, between the 20th of March and the 23rd of September, 

 and from o through c to o, between the 23rd of September and 

 the 20th of March. Now, not only is the latter segment of the 

 oval shorter than the former, but the motion of the earth while 

 passing over it is more rapid. On both accounts, therefore, the 

 time of moving from o to c is less than the time of moving from 

 c to o ; and, accordingly, we find that the interval from the 20th 

 of March to the 23rd of September is nine days longer than the 

 interval from the 23rd of September to the 20th of March. 



It may here be observed in passing as a curious fact, that the 

 earth is nearer the sun at the winter than at the summer solstice, 

 and it might therefore be supposed that the temperature of the 

 seasons ought to be reversed. But the effect of this difference of 

 distance is incomparably smaller than the effect due to the greater 

 length of the day and the greater altitude of the sun, and these 

 latter consequently predominate. 



70. The sun moving in a year round the entire ecliptic, and 

 therefore passing over 360, moves over 30 per month. The 

 ecliptic being conceived therefore to be divided into twelve equal 

 parts of 30, each of these parts is called a SIGN. 



A certain zone of the heavens, extending to about 9 at each 

 side of the ecliptic, is called the ZODIAC. 



The zodiac, like the ecliptic, which runs along its middle, is 

 conceived to be divided into twelve equal parts, called THE SIGNS 

 OF THE ZODIAC. 



The signs are supposed to begin at the point through which the 

 sun passes at the March equinox, and to follow the course of the 

 sun, so that the last in order of the signs is that through which 

 the sun passes in the thirty days which precede the March 

 equinox. 



71. In ancient times the successive divisions of the zodiac 

 which have been called signs, were occupied by certain conspicuous- 

 constellations or groups of stars, and each sign took its name from 

 the constellation of which it was thus the place. It was and still 

 is the custom to give names to constellations taken- from animals, 

 or mythological and historical personages. They have been 

 generally called by their Latin names, which are given in the 

 first column of the following table ; the English names are given 

 in the second, the symbol by which they are indicated in 

 almanacks and calendars in the third. The days of the civil 

 year upon which the sun enters the successive signs vary with the 

 variation of the day of the equinox, the cause of which has been 

 already explained. In the fourth column of the annexed table, 



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