Nipher — The Law of Contraction of Gaseous Nebulae. 161 



-n—l\ ^ I - J(n—1)^^ ^ 



By (5) and (33) this becomes 



W=-(C,+ Cj.+ ^'jT^ip-l). (42; 



Hence 



^- C- ^ = 0.75. (43) 



(7,-|-(7p+4j 2Cj.+ Sj 



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

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

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

 used in causing a rise of temperature. 



The same result may be obtained from Ritter 's equation 



4 

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



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) 



W-Q ^ C- C, 



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



true. Equations (43) and (44) assert th^vt for a rise of tem- 



O 

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



C 

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



u 

 (J 

 are radiated, and Qp — -j = C^ heat units are used in raising 



the temperature. 



