243 
the obliquity of the Ecliptic, &c. 
It has been proposed to make the two results agree, by an 
increase of the quantity of Bradley’s mean refraction ; but 
this could not be done, without increasing it by a quantity 
greater than can be justified by other determinations respect- 
ing refraction. 
Considering then this uncertainty respecting the observa- 
tions of the winter solstice, it appears better to compare the 
results from Dr. Bradley’s summer solstices, with the result 
as deduced from the mean of the observations of different 
astronomers. 
Mean Obliquity, Jan. 1, 1813. 
M. Oriani* * 
Mr. PoND'f’ 
Mr. AragoJ 
Dr. Brinkley 
4 summer solstices 
2 summer solstices 
2 summer solstices 
8 summer solstices 
23 0 2/ 50", 34 
23 27 50 ,37 
2 3 27 30 ,09 
23 27 5o >99 
Mean Jan. 1. 1813 23 27 30,45 
Dr. Bradley, Jan. 1. 1755 23 28 15 ,49 
diff. 58 years. 25 ,04 
This gives of 43, for the annual diminution. 
The mean of 18 observations near the winter solstice gives 
me mean obliquity Jan. 1, 3813, 23 0 27' 48", 14. 
The above determination of the obliquity by observations 
near the summer solstice gives (taking the annual diminu- 
tion o",43.) 
Mean obliquity Jan. 1, 1800=23° 27' 56°, o, differing only 
1" from that assumed in M. Delambre’s tables of the sun. 
* See Mr. Bessel’s work, p. 62. 
+ Phil. Trans. 1813, p. 304. This is corrected for the solar nutation. 
J Conn, des Temps. 1816. The observations were made with a three feet repeating 
circle. 
