Nipher — On Temperatures in Gaseous Nebulae. 283 



Substituting the numerical values above given, in equation 

 (27), the common log. of B is found to be at present, 



log B = 0.000,000,000,0773. 



B is also a time function. From the initial condition to 

 the present time, the base B has increased from unity to 



B= 1.000,000,000,178. 



If the value of T in (28) be substituted in (3) and this 

 equation be combined with (2) by eliminating (5, the resulting 

 equation may be solved for M. The result is 



This equation being differentiated with respect to i?, gives 



cZ / dP \ dP d / pT>R\ 



dM^ GT,^ dR\^ dB)~^ jRdE^ ^' (30) 

 dR~ k P2 jgm 



By geometry and by equations (3) and (28), 



dM _ ^itR^PB^ ,„., 



dR = ^'^^''=~-UTr ^''^ 



Performing the indicated operations in (30) and equating 

 with (31), the differential equation for P, in terms of H is 



d'P.i^ , n\dP I (dPy i-rrkJ^B^" „ ,„„. 

 dIP+[E-'°S^}dB-p[dB) +~WTr= ^ ^ 



If the primitive of this equation can be found, it may lead 

 to a further comparison of the conditions involved in equa- 

 tion (26) with those known to exist in the sun. The general 

 lines on which such discussion may be made, have been laid 

 down in the present paper, and in the former one to which 

 reference has been made. 



