16 Memoir on the Diminution of the 
Siganfou, the capital of the empire. On the day Kouey-hang 
of the. 5th moon (igth June) was the summer solstice ; the 
noon shadow was one foot four inches six fen. 
** On the day Ping-you of the 11th moon (19th Dec.) 
was the winter solstice 5 the noon shadow was twelve feet 
31x inches three fen.’ 
The summer shadow gives for the altitude of the sun’s 
centre, corrected by Ene refraction and: parallax, 79° 23’ 
31,6. "d 
The winter shadow gives for the same ality corrected 
in like manner, 32? 3 Y Ble eds 
The di ania between. these two latitudes. i is 47° 90° 
10”,3, of which the half, 23° 40’ 5,1, is the ecliptic’s obli- 
quity as determined by these observations. _ According to 
the new Tables founded on the formulas of Méc. Céd. the 
ecliptic’s obliquity should have been at that period, 23° 
38 7’. The difference is not very considerable, consider- . 
ing ie uncertainty of the observations. 
The pole’s altitade at Siganfou resulting therefrom is 
34° 16’ 33",5.. This altiude. has been observed, to be 34° 
16,0 by he Jesuits’ missionaries. This agreement is a 
proof of the justness of the observations. 
-I am at last arrived at the numerous and exact observa- 
tions of the greatest astronomer China has to boast of, Co- 
cheou King: No observer before bim has left duck ac- 
curate observations as his. Their accuracy is even greater 
than that of the observation of Tycho: it 1s owing to the 
magnitudé of the instrument he made use of, and to the, 
precautions he took to ascertain its adjustment: I shall 
first relate the observations of the quoted MS. (Cunn. des 
Tems for 1809, p. 392.) 
«« Winter solstice at Peking. This solstice is marked for - 
the year Ting-tcheou of the empire of Cobilay (1277), at 
7° 43’ of the morning of the day Kouey mao (14th Dec.) © 
«« Summer solstice at Peking, in the year Vou-yu of Co- 
bilay’s empire (1278), at,10" 43’ 12” in the morning of the 
day Y-se of the 5th moon (14th June). ‘ 
‘¢ Winter solstice at Peking, for the year Ky-mao of Co- 
bilay’s (1279), 4° 33’ 36” of the morning of the day Sin- 
hao of the 5th moon (15th June.) 
*¢ Winter solstice at Peking, of the year Ky-mao of Co- 
bilay (1279), 7° 28’ 48” at night, of the day Kouey- eet 
“(14th December) of the 11th moon. 
** Winter solstice at Peking, of Kentchin; of Cobia 
(i280), 1" 26’ 24” after midnight of the day Ry: an of _ 
11th moon (14th December. ) iced 
“ These 
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