COBLENTZ: CONSTANTS OF SPECTRAL RADIATION 



179 



would give a mean value of c = 14465 ± 40 and that the values 

 published by Paschen, if similarly corrected would give a mean 

 value of c = 14458 ± 25. 



The most recent communication from Warburg"* and his associ- 

 ates gives a mean value of c = 14374 ± 4. The mean value of 

 the four sets of investigations weighted as follows {L and P = I 

 P =3, W = 10 and C = 10) gives a mean value of; 



c = 14420 mikron deg. 

 a = 2905 mikron deg. 



The mean value of the most recent work by Warburg and by the 

 writer is c = 14415. 



TABLE I 



Mean value c = 14,456 ± 4 (94 energy curves) 

 A = 2911 ± 1 



The value c = 14420 is a convenient one to use. The differ- 

 ence in the values obtained by Warburg and by the writer indi- 

 cates an uncertainty of about 5° at 1750°C. It is rather remarkable 



^ Warburg — Leithaiiser, Hupka, Miiller, Sitzbei', Akad, Wiss. Berlin I, p. 35. 

 1913. 



