Tables 40 {concluded) and 41 



103 



Fundamental constants, Birge. — The critical discussion of the determina- 

 tion by Dr. R. T. Birge of theses values will be found in abbreviated form on 

 pages 73 t0 I02 °f tn i s book; for full details see Phys. Rev. Suppl., 1, 1, 1929. 

 These constants, for purposes of computation, are to be taken as exactly 

 correct ; that is, all additional digits in each constant are to be assumed as zero. 

 The real probable error of each value is of course that indicated in the table, 

 and each constant has an accepted value carried only to the number of signifi- 

 cant figures required by the adopted probable error. 



Velocity of light c= (2.99796 ± 0.00004) X io 10 cm • sec." 1 



Gravitation constant G = (6.664 — 0.002) X I0" s dyne ■ cm 2 • g" 2 



Liter / = 1 000.027 ± 0.001 cm 3 



Volume of perfect gas (o°C, An) . .vn= (22.4141 ± 0.0008) X io 3 cm 3 -mole" 1 

 Volume of perfect gas (o°C, A^) . . .R = 22.4146 ± 0.0008 liter • mole -1 

 International ohm = p abs. ohm. ...p== 1. 00051 ± 0.00002 

 International ampere = q abs. amp. .q = 0.99995 ± 0.00005 



Normal atmosphere A n = (1.013249 ± 0.000003) X io 6 dyne • cm" 3 



45 atmosphere A^= (1.013199 ± 0.000003) X io 8 dyne • cm" 2 



Ice point (absolute scale) To = 273.18 ± 0.03°K. 



Mechanical equivalent of heat /i 5 = 4.1852 ± 0.0006 abs. joule • cal.15" 1 



Electrical equivalent of heat /'is = 4.1835 ± 0.0007 i nt - joule • cal.15" 1 



Faraday constant F = 96494 ± 5 int. coul. • g-equiv." 1 



—- 96489 ± 7 abs. coul. • g-equiv." 1 

 = 9648.9 ± o.j abs. rm-unit • g-equiv." 1 

 Fc= (2.89270 ± 0.0002) X io 14 abs. «-unit • g-equiv." 1 



Electronic charge * e = (4.770 ± 0.005) X io" 10 abs. c^-units 



e/c —. (1.59106 ± 0.0016) X io" 20 abs. ^m-units 

 Specific electronic charge (spectro- 

 scopic) c/m = (1.761 ± 0.001) X io 7 abs. cm-unit g" 1 



(c/m)c= (5.27941 ± 0.003) X io 17 abs. r^-unit ■ g" 1 

 Specific electronic charge (deflec- 

 tion) c/m = (1.769 ± 0.002) X io T abs. cm-unit ■ g" 1 



(c/m)c = (5.30339 ± 0.006) X io 17 abs. <\y-unit • g" 1 

 Planck constant * h = (6.547 — 0.008) X io" 27 erg • sec. 



Atomic weights 



= i6.oooo C = 12.003 — 0.00 1 I = 126.932 ± 0.002 



He = 4.0022 ± 0.0004 H = 1 .00777 — 0.00002 Ca = 40.075 ± 0.005 



Ag = 107.880 ± 0.00 1 N = 14.0083 ± 0.0008 



* Millikan, Phys. Rev., 35. 1930, takes e = 4.774 X io'°, h - 6.547 X IO-», A' = 6.062 X 10- 

 Smithsonian Tables 



