810 



Dr. Gr. Rudorf on the Molecular and 



obtained in Part I. The following table gives the comparison 

 between the different methods of calculation : — 



Lord Kelvin's formula. 

 N<x 2 =0'1629^. 



N ff 2 = 0075^ 

 n 



Taking ,o=0-001781 

 G=4'14xl0 4 

 Taking ^=0'0002083 



Na2= 57700 



1 



Taking L 



\/27rN<T 2 



3-89xl0-6| 



Taking p = 0-001782 

 G=4-13xKM 

 Taking ^=0-0002114 

 N<r 3 = 26200 



L=866xl0-( 



Go 

 Na2 = 0-0643 — ■ 

 V 



Taking p =0-001782 

 G=4-13xl0 4 

 Taking ^=0-0002114 

 Na2= 22500 



Taking L= ,— _ a 



L=10-07xl0- 



In order to get at the valne for a Lord Kelvin formed an 

 estimate of N from the density of liquid argon, taking for 

 this Ramsay and Travers's value - 1*212. Assuming that 

 the molecules are qa apart, where q is some numerical factor, 

 he put 



f liq. 



1-212 



N{qcr) 3 

 and as N<r 2 = 57700, 



= 681, 



■ Pg&s ~ 0-001781 



N = 681 2 . 57700V = 8-9 x lO 19 ^. 



Seeing that q could not very well be less than unity, he 

 took # = 1*02 to make N = 10 20 , and substituting this value for 

 N in No- 2 = 57700, obtained for a the value 2'40 x 10" 8 cm. 



Now this calculation, apart from the fact that the figures 

 are inaccurate, also contains a fallacy, inasmuch as the factor 



^ is omitted. 

 6 



The relation should be 



In conclusion, we will calculate the value of q, 

 No- 2 =22500and4,, = l-423. We have 



1 1-423 _ so „ 



taking 



and 



/tf\ 2 ? _ 3-65 q q 



