332 SPECIAL RESULTS IN THE URANOLOGICAL 



high antiquity of Chinese civilisation. There are remains 

 of Chinese literature scarcely a century less ancient ; and a 

 regular historic chronology reaches back (according to 

 Edouard Biot) to 2700 years before our era ( 532 ). Under 

 the Regency of Tscheu-kung, brother of Wu-wang, the 

 length of the sun's meridian shadow ( 533 ) was measured at 

 the summer and winter solstice, with an 8-foot gnomon, at 

 the town of Lo-jang, to the south of the Yellow River, in 

 latitude 34 46' (the present name of the town is Ho-nang- 

 fu, in the Province of Ho-nan.) These measurements 

 gave the obliquity of the ecliptic 23 54' ; being 27' greater 

 than it was in 1850. The observations of Pytheas and 

 Eratosthenes at Marseilles and Alexandria are six and seven 

 centuries later. We possess four results respecting the 

 amount of the obliquity of the ecliptic previous to our era, 

 and seven results intermediate between that period and 

 Ulugh Beg's observations at the Observatory of Samarcand. 

 The theory of Laplace agrees admirably, having differences 

 which are sometimes plus and sometimes minus, with the 

 observations extending over a period of almost 3000 years. 

 "We are more fortunate in the knowledge of the early Chinese 

 measurements of the length of the solar shadow, as the 

 writing containing the account escaped, we know not how 

 or why, from the great destruction of books which took 

 place from motives of fanaticism, by the orders of the Emperor 

 Shi-hoang-ti of the Tsin dynasty, 246 years before our era. 

 As, according to the researches of Lepsius, the commence- 

 ment of the 4th Egyptian dynasty, which began with the 

 reigns of the pyramid -building kings, Chufu, Shafra, and 

 Menkera, was 23 centuries anterior to the solstitial obser- 

 vation at Lo-jang, we may assume with very great probabi- 



