Nipher — TTie Law of Contraction of Gaseous Nebulae. 161 



n—l\ ^ j — J {n—\) ^^ ^ 



By (5) and (33) this becomes 



W = -I^O„+ ep+4r) ^o(p-l). (42; 



Hence 



O C 



^= 0= ^==0.75. (43) 



(7„+(7^+4j 2CV+3^ 



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 -g. 



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) 



C C 



^ — ^ "^==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 that for a rise of tem- 



C 

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



'J 



C 

 H applied to the unit mass, of which (7^+4-y heat units 



C 

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



the temperature. 



