TO ASTRONOMY. 29 



a vernal period of the great year. For although 

 there would be perpetual summer at the equator, 

 and a gradual diminution of temperature on to 

 the highest latitudes, there would be no winter. 

 In short, the days and nights would be every 

 where of the same length, except immediately 

 around the poles, which would be always illumi- 

 nated, and there would be no variety of seasons, 

 but an unceasing verdure would everywhere 

 prevail. And that the earth may have fre- 

 quently passed through such a state, is highly 

 probable from the fact, that at the present 

 moment, the axis of Jupiter has very little if any 

 inclination. And that this inclination has an 

 extensive range of variation, would further ap- 

 pear from the fact, that in the case of Saturn it 

 is now 28 40', while in that of Mars it is 30 18', 

 according to Sir John Herschel. There is there- 

 fore no obvious reason why the inclination of 

 the earth's axis should not go on augmenting 

 until it arrives at the same angle.* 



* In reality, it is more in accordance with analogy to sup- 

 pose that this variation may pass through an entire revolution, 

 than that it is confined within the narrow limits of 2 or 3. 

 Should such a revolution go on uniformly at the rate of 48" in 

 a century, its completion would require a period of 2,700,000 

 years, unless interrupted by a conjunction of all the planets ; an 

 event which the ancients regarded with dread, as the cause of 

 deluges, or some other signal catastrophe. We are informed by 

 Mr. Samuel Davis, that, according to the Surya Siddhdnta, the 

 oldest Hindoo work on Astronomy, the obliquity of the ecliptic 

 was 24, when it was written ; which must therefore have been 

 4000 years before the 19th century. (Asiatic Researches, vol. ii.) 



