160 Trons. Acad. Sci. of St. Louis. 



These values in T are very interesting. They show that 

 while the average temperature within any concentric spherical 

 surface is but little above the temperature at the surface, the 

 gas has this average temperature at a distance 0.707i2 from 

 the center. It will also be observed that if the temperature 

 were uniform throughout the mass, or ?i =: 1, the value of R^ 

 computed from the above equation would be 1^ JR. This, of 

 course, means that the average temperature would be anywhere 

 between and H. 



Ritter computes the ratio of the heat per unit mass radiated 

 from the nebula during contraction from a condition P^, v^, T^, 

 to a condition P, v, T, to the total work done on this unit mass 

 during the same operation. Both quantities are measured in 

 heat units. He finds the ratio to be 



Q 



^=0.187. 



According to this only 18.7% of the heat developed by 

 the work done on each unit mass, is radiated. The remainder 

 of the heat goes to raise the temperature of the mass. By 

 the equations of this paper, the heat radiated is (28), (33), 



= -[0p + 4^)(r-r,) 



= -[0l> + ^^T,{P-1) (41). 



The work done on unit mass in the same operation is 

 (since P,?j," = Pv") 



W 



Cpdv=P,v- I J 



V 

 dv 



