NipJier — The Laiv of Contraction of Gaseous Nebulae. 161 



-n—l\ ^J~ J(n—l)^^ ^ 



By (5) iind (33) this becomes 



W=-(^C,+ 6V+ ^) T,{P-1)- (42; 



Hence 



O C 



^ c^ + ^j a^+4^ 



According to this equation, the heat radiated is 75% of the 

 heat equivalent to the work of compression, and not 18.7%, 

 as Eitter found. Only 25% of the energy of compression is 

 used in causing a rise of temperature. 



The same result may be obtained from Eitter 's equation 



4 



(80), p. 554, by making his value e = 1.1 instead of -r. 



The numerator of (43) is the specific heat of gravitational 

 compression as determined in (33). It is evident that 

 W — Q must be the heat applied to the unit mass of gas, and 

 causing a rise of temperature. By (43) 



3.0. (44) 



This result deduced in (44) is exactly what we know to be 



true. Equations (43) and (44) assert that for a rise of tem- 



(J 

 perature of 1° C, energy equivalent to 2(7p+ 3 -^ heat units 



G 

 ^s applied to the unit mass, of which Cp+4-y heat units 



(J 



are radiated, and C p — -j=^G„ heat units are used in raising 

 the temperature. 



