COMMON THINGS THE ALMANACK. 



the days on which the sun enters them severally when the equinox 

 falls on the 21st of March, are given. 



72. It appears therefore that the day of the spring equinox 

 the sun enters Aries, that of the summer solstice, Cancer, that of 

 the autumn equinox, Libra, and that of the winter solstice, 

 Capricorn. 



The points through which the sun passes at the solstices have 

 therefore been called the TROPIC OF CANCER and the TROPIC OF 

 CAPRICORN respectively. 



73. It has been shown in our Tract on " Time," that the equi- 

 noctial points, and consequently all the signs of the zodiac, have a 

 slow backward motion on the firmament at the rate of a degree in 

 72 years. They would therefore move back through 30, or an 

 entire sign, in 2160 years. Now it is known that in the time of 

 an illustrious astronomer, Hipparchus, who nourished in Rhodes 

 and Alexandria about 150 years before Christ, that is above 2000 

 years ago, the vernal equinoctial point was? in the constellation of 

 Aries, from which the first sign of the zodiac took its name, and 

 consequently that all the other zodiacal constellations were at the 

 same epoch in their proper signs. But in the interval of 2000 

 years, the equinoctial points having, as above stated, moved back- 

 wards through about 30, they have severally retired from their 

 proper constellations, which are now consequently that distance 

 before them ; so that the second sign of the zodiac is occupied by 

 the constellation ARIES, which gave its name to the FIRST sign, 

 the third by the constellation TAURUS, which gave its name to the 

 SECOND sign, and so on. 



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