﻿476 



Dr. Norman Campbell 



on 



14. From these new and more accurate values o£ ya, 

 v and V are again calculated. The results obtained are 

 given at the head of Table XXII., in which the values of /x 

 calculated are compared with those deduced directly from 

 the curves. The agreement is not unsatisfactory, though it 

 is not quite so good as that of the experiments ol Townsend, 

 considered in the previous paper. It is possible that the 

 values of //, for aluminium are consistently somewhat smaller 

 than those for gold, but the discrepancy is not greater than 

 can be accounted for by the errors in n already mentioned. 



Table XXII. 

 V' = 2O75±0-08. v= 1-807 + -008. 



y- 



ft. | 



I* cale. — /x Au. 



fJ- calc. — it. Al. 



' 102;2 



1-019 



-•016 



+ •043 



71-54 



0-839 



+ •009 



•000 



51-10 

 41-48 

 40-88 



0-663 

 0-554 

 0-547 



-•003 

 -•022 



-•0211 

 -•003 } 



-•004 



31-11 



20-74 



0-411 

 0-229 



+ •005 

 -•003 



•oooi 



+ •002 \ 



10-37 



0-0443 



-015 



+ •007 



In the last stage of the approximation R is recalculated 

 from the new values of v and V, and for jju the calculated 

 value from Table XXII. used ; P is then calculated for each 

 of the tables ; the value obtained for P is given in Table 

 XXIII. ; it will be observed that it differs very slightly from 

 the previous approximation of Table XXI. From these 

 values of P 5 n x is found by means of the relation 



p-{«i+»'( e +y) 



— )> e 



flC, 



The value is given under n (calc.) ; in the column marked 

 n (corr.) these values are corrected for the decay of the 

 polonium, and all reduced to the same date ; if the theory 

 and the experiments were perfectly accurate the figures in 

 this column would be constant. Since all the error in P is 

 thrown on w 1? in taking the mean the weights of the various 

 values of n x are taking as inversely proportional to P, and 

 the numbers in the column marked " error " are the diver- 

 gences from the mean expressed as fractions of P. It will 



