Tables 307 and 308 



TABLE 307. — Radiation Constants and Formulae for Black Body 



3*3 



The radiation per cm 2 from a "black body" (exclusive of convection losses) at the tem- 

 perature T° K. (Centigrade degrees) to one at 7VK. is J = a (T 4 — TV), (Stefan. Boltzman) 

 where a = 2ir b k 4 /i5 c 2 h 3 = (5.7139 ± 0.006) X 10- 5 erg-cm- 2 -deg.- 4 sec." 1 (Birge) (indirect) 

 .= (5-735 ±o.on)Xio- 5 erg-cm- 2 -deg.- 4 sec.- 1 (Birge) (experimental). 



The distribution of this energy in the spectrum is represented by Planck's formula: 



CI 



J x = Cl X- 5 (e XT - i)-y\ 

 where J\ represents the intensity at wave length X 



*C\ = (3-697 ±0.005) X io^ergcm^sec.- 1 , unpolarized radiation over solid angle 2ir. 

 = (3.194 ± 0.004) erg-cm 2 - day 1 

 = (8.832 ± 0.01) X io 13 g cal.16 cm 2 - deg. 

 = (3.697 ± 0.005) X io- 12 watts-cm 2 

 d = (1.432 ± 0.003) cm-deg. 

 J max. =3.11 X io 6 T b 



\ max T = £2/4.9651 = (0.28836 ± 0.00011) cm-deg. 

 *d = 27i7zc 2 = 3.697 X 10- 5 erg-cn^-sec." 1 when E x d\ denotes the emission of unpolarized 

 radiation in range d\, per unit surface in all directions (2ir solid angle). 



d = 8irhc = 4.932 X io- 15 cm-deg., when E^d\ denotes energy density of unpolarized 

 radiation. 



Ci = he- = 0.5884 X IO' 5 erg-cm^-sec.- 1 , when E-yd\ denotes intensity of linearly polar- 

 ized radiation in range d\, perpendicularly to a surface, per unit surface, per unit solid angle. 



TABLE 308. — Radiation in ergs (R x 10") and gram-calories (R 1 x 10") per cm" 

 per sec. from a perfect radiator at t°C to absolutely cold space (— 273°C) 



Computed from Stefan- Boltzman formula, a = 5.73 X 10- 5 erg. cm.- 2 deg.- 4 



Note: Above table correct probably to one per cent. 

 Smithsonian Tables 



