838 S. Kinoshita, S. Nishiktiwa, and S. Ono on Amount 



mobility, the theory explains why the variation of the rela- 

 tive amount of the radium deposits on the upper and lower 



wires, ~ say, ought to be as observed. According to 



Q: 



Qi 



ihe calculation, ~~ should be equal to fi x : />t 2 = *87. if 



Ws ~7 \±T^ — /"' wmcn * s 10"8 cm. per sec. for the upper wire, 



and 40'0 cm. per sec. for the lower. Therefore, if w s < 40 cm. 



per sec, — will be greater than the above value. In the 



W2 

 limiting case, in which there is no wind at all, or the direction 



of the wind coincides with that of the wire, then ~ should 



, -75 ... ^ 2 



be # 87 X -^ =2'6. Consequently, in ordinary circumstances, 



^ :j 



q- will lie between "87 and a value a little greater than that. 



As is seen from Column IV. Table I., it varied from -00 to 

 l'Ol on different occasions, as is to be expected. 



(21) We have already mentioned that the distribution of 

 the thorium emanation in the atmosphere cannot be uniform. 

 Moreover, it is not probable that thorium A having the 

 period of* 106 hours is in radioactive equilibrium with the 

 emanation in situ. Consequently, the ratio of the amounts 



of deposits on the upper and lower wires or ~ f will not be as 



fiy : /z 2 ,but will vary much with the vertical component velocity 

 of the wind, which is in a fair proportion with the horizontal 

 component velocity. Experiment showed that this was the 



' 

 case, jyj varied within the wide range between *24 and 



'72, as can be seen from Column VII. Table I. To show 



the variation of 7=A with the velocity of wind, the following 



S?2 



figures are taken from the same table. 



Table III. 



1 



Date. 



Q':QJ 



16 



•24 

 10 



17 



•56 

 5 



18 



•57 

 4 



19 



•67 

 2 



6-5 

 2 



19 



•72 

 1 



10-1 

 1 



20 



T2" 

 3 



4-8 



3 



21 



•31 

 9 



1-9 



9 



23 



•38 

 8 



IT 



7 



24 



•44 



7 



31 

 8 



_25_ 



•48 

 6 



3-5 

 5 



Order of magnitude... 



< 

 Mean vel. of wind ... 



! Order of magnitude... 



1-2 



10 



3-5 

 6 



3-6 

 4 



