J. H. Lane on the Theoretical Temperature of the Sun. 67 
the combination of wire and oxygen under the atmos- 
eric pressure to be ae Cent. As the lime in the heated 
last would radiate rapidly, its temperature must have been 
lower than that of combined h ee and oxygen, and 1 have 
called it 2220° Cent. or 4000° 
e formula of Dulong and Petit, with the co-efficient found 
by Hopkins, as already Saas tye gives for the quantity of 
8 re (0077) [(1-0077)*—1]. 
It will be convenient, and, in the discussion of the high tem- 
peratures with which we are concerned, will involve no sensible 
error, to use the hypothesis that the space around the radiating 
body is at the esa of 0° C. and the formula for the 
ieee then 
8 8377 [(1-0077)* —1}. (21) 
The unit used b tl a in the formula here given, is the 
quantity of heat tbe 0 
of water 1° cen : nomen fw af the zane 
under 
uare foot of its surface, at its ture of 4000° 
Fah. If now we calculate its temperature by the above formula, 
from the estimated radiation, the nd is 1166° ae or 2130° 
This rature, 
and so far below that there can be no doubt tha formula of 
Dulong and Petit has failed at the melting point of lime. If 
