Obliquiiy of the Ecliptic. 17 
_ ** These solsiices were determined by Cocheou-King, ac- 
cording to Tsou-ichong’s method, as before related. Tsou- 
tchong only made use of three observations; his gnomon 
was eight feet long, Cocheou: King made use.of seven, 
eight, nine, ten corresponding observations ;and his gnomon 
Was 40 feet long.— The last solstice in the epocha of Ccbi- 
lay’s Astronomy, as set right by Cocheou-King. 
** The solstices deserve to be examined, hecause of the 
noon shadow observed by Cocheou-King with that gnomon, 
(Coun. des Tems for 1809, p- 399.) He madeasmall aperture 
in a sheet of copper to transmit the sun’s image. This aper- 
ture, says he, was like that of a needle; and from the centre 
of that hole it was that he took the height of the gnomon, 
and he measured the shadow as far as the centre of the 
image. Till then, says he, eight-foot gnomons only 
were used, and by their means the upper edge of the sun 
only was observed: it was difficult (he adds) to distinguish 
the’ edge of the shadow, and the eight-foot gnomon was 
too short. These are the reasons (continues Cacheou- King) 
that have induced me to make use of a gnomon forty feet 
long, and to take the image of the sun’s centre. ; 
** At Pekin, in the summer solstice, with a forty-foot 
_ gnomon, meridian shadow of the sun’s centre eleven feet 
seven inches; in the winter solstice, 79 feet eight inches. 
“Ii was in the years 1277, -78, -79, and -80, that Co- 
cheou-King made these observations, and considering the 
pains he took for levelling and the ascertaining of the mea- 
sures, they appear exact. 
- “In the year 1279, and onthe day Y-oueyof the 2d moon 
(31st March), noon shadow of the sun’s’centre 26 feet three 
inches four li five hao. 
: Feet. Iich. Fen. Li. Hao. 
*© On the 16th March, ucomshadow 32 1 9 5 5 
“On the 29th August, .. do. .. 25° 89.9 0 
“© On the 29th June, oe iGos Shee snsiGy yO 
“© On the 29th November, do. .. 76 7 4 0 O 
“< In the year 1278, 10th June, do. 11 7 7.75 
*« There were many other noon shadows taken by means 
of that forty-foot guumon. If they are wished for, they 
will be detailed.” 
It is much to be regretted, on account of the exactness 
of these observations, that they were pot given in a greater 
number; and that Father Gaubil’s offer has produced no 
effect. It is very desirable that the learned and missionaries 
in China, who are able to obtain them, may be inyited to 
make them known to us, and to give us, on the subject 
Vol. 37. No. 153, Jan, 1811. B eae 
Sees 
