806 



Dr. Gr. Rudorf on the Molecular and 



-s 



From I. we get for Helium 0-= 1-696 x 10~° cm., 



and for 



Argon <r = 2-85 X 10" 



cm. 



From II. we get for Helium o- = 2'02 x 10 -8 cm., 

 and for Argon c = 3 , 39 x 10 -8 cm. 

 Jeans himself calculated a from his formula, using Lord 

 Rayleigh's values of v and taking N = 4*0xl0 19 . He 

 obtained for 



Helium, a- = 1*81 x 10~ 8 cm., 

 and for Argon, cr — 2*786 x 10 -8 cm. 



In concluding this section, we will recapitulate in 

 tabular form all the results obtained above. 





Molecular Velocities. 









He. 



Ne. 



A. 



Kr. 



X. 



G xl0~ * cm. /sec. ... 

 Q XlO— 4 cm./sec. ... 



13-11 



12-08 



5845 

 5-385 



4-13 

 3-806 



2-86 

 2-64 



2-28 

 210 



Mean free paths. 

 He, L =2-85 xl0- 5 cm. 

 A, L = l-006xl0 



-5 



cm. 



Molecular Diameters. 





a X 10 s cm. 



He. j Ne. A. 



Kr. 



X. 



I. 



From (t = Qs/2\L. 

 (a) V from density of liquid ... 



28-5 

 435 

 0-597 

 0-559 



... 10-7 



... 2-87 



... , i-59 







(c) V from dielectric constant ... 



(d) V from refractive index 



II. 



From ff=4-58 V2VL. 

 (a) V from density of liquid ... 

 (6) V from coefficient b 



21-8 



3-32 ; ... 

 0-455 ... 

 0-426 ... 



8 16 

 2-19 



1-21 



4-93 

 3-14 



2*69 



4-88 

 3-42 



3 : 16 



(c) V from dielectric constant... 



(d) V from refractive index 



From V=-.Nff» 

 (5 



(a) V from density of liquid . . . 



(b) Y from coefficient b 



(c) V from dielectric constant... 



(d) V from refractive index 



4-34 

 2-3 

 1-20 

 1-17 



1-47 



4-43 

 2-86 



2-35 



IV. 



From the viscosity coefficient. 

 a. Meyer's formula 



1-696 ... 

 202 I -.. 



2-85 

 3-39 







b. Jeans's formula 















