. 
64 J. H. Lane on the Theoretical Temperature of the Sun. 
and (11). Otherwise, the same process employed with the value 
b=1-4, gives, starting with « = 1, «= 2875 and (4 a = 8459, 
and meat iets for c=1, c=172, &., brings us to u=2°557 
and ie )'= ='1591, for z=3-0, and finally gives us 
: a'—=3°656, w’=2°741, 
and if we now assume the same height as before for the theo- 
retic epee limit of the sun’s atmosphere, instead of ¢,=28°16, 
we fin 
Ctl. 
The new curve of deneity: is found in the same way as the 
first, and is presented to the eye in the diagram in comparison 
with it. In the upper part of both curves the scale of density 
is increased ten fold, and it is, in part only, evident to the eye 
how immensely different, for the two values of &, becomes the 
density in the upper parts of the sun’s mass. It appears to the 
eye only in p cause the ratio of the two densities multi- 
plies itself rapidly in approaching the upper limit of the at- 
mosphere. 
The above was communicated in writing as here given, to the 
Academy at its late session.* The draft ‘of the following, and 
a part of the details of its substance, have been prepared since. 
Equation (20) gives in feet the squaré root of the mean square 
of velocity of translation of molecules (8° 020/300). At the 
sun’s center we find this would be 831 miles per second for the 
rve of density corres te to k=14, and oy miles per 
second for the curve of 
from Pouillet’s s obsarvatiens: and his own made at the Caps of 
Good Hope about the same time, adopts, after allowing one- 
third for the absorption of our atmosphere. re, forty feet as the 
thickness of ice that would be melted per minute at the sun’s sur- 
* T desire here to state that the formule which show the relation between the 
temperature, the pressure, the density, and the depth ‘tes the upper limit of the 
atmosphere, so far as they apply to the upper part of the sun’s body, were inde- 
pendently pointed out by Prof. ree in a very seh ing paper which that dis- 
$e : 
given the term convective equilibri such that any portio 7 the sie, 
— —s into any new layer beret below, would Hen itself reduced, by 
its expansion or compression, to the temperature of the new layer. 
