ON THE EFFECTIVE TEMPERATURE OF THE SUN. 
393 
Means of Daily Means. 
Therefore 
Position lA . 
. 7236° . 
7 observations. 
7032° . 
• . 0 
6957° . 
. . 3 
7008° . 
. . 3 
Mean . 
. 7058° 
Position 2A . 
. 734.3° . 
5 observations. 
7100° . 
. . 10 
Mean . 
. 7222° 
Mean of lA and 2A ; 
= 7140°. 
Position IB . . 
. 5797° . 
9 observations. 
5671° . 
. . 6 
5713° . 
. . 3 
Mean . 
. 5727° 
Position 2B . 
. 5884° . 
9 observations. 
5993° . 
. . 6 
5659° . 
. . 3 
l\Iean . 
. 5639° 
Mean 
of IB and 2B 
= 5683. 
?? 
lA and 2A 
= 7140. 
Mean result = \/5083 X 7140 = 0370° absolute. 
To this 100° must be added for the reason on page 387. 
As there must necessarily be errors of observation, and as results on different days 
give values differing by as much as 300°, chiefly owing, no doubt, to a change 
in atmospheric conditions, it has been considered unnecessary to go into certain 
refinements in the calculation such as using the method of least squares. The 
daily means have also been given equal weights, in spite of differences in the number 
of observations. 
The geometrical instead of the arithmetical mean of the calculated temperature in 
the A and B positions, is taken for the following reason : 
MDCCCXCIV.-A. 3 E 
