20 Mr. J. Satterly on the Amount of Radium 



(2) It is to be noticed that in England rain nearly always 

 accompanies a decrease in the amount of emanation, so that it 

 is advisable next to draw up a table showing the effect of rain 

 (D again means a decided chan ge in the amount of emanation) . 



Table VII.— Effect of Rain (or No Rain). 



No Effect. 



Decrease. 



Increase. 



Decrease 

 when no rain. 



Increase 

 when no rain. 





Before Mar. 15 



1 







Mar. 2-4 (Snow) 



Mar. 23-25 (D) 

 „ 29-Apl. 1(D) 





Mar. 15-17 (D) 



Mar. 3-5 (D) 

 „ 31-Ap.2(D) 





April 27-30 





May 4-7 

 „ 10-13 (D) 



May 3-5 

 „ 12-14 





May 24-27 





„ 18-21 (D) 



„ 17-19 (D) 





„ 31- June 2 (D) 







„ 27-28 (D) 



- 



Before Aug. 2 





June 7-10 

 ., 14-17 (D) 



June 16-18(D) 





Aug. 16- 20(D) 





Aug. 4-6 



Aug. 2-5 (D) 





„ 24-26 (D) 



Aug. 23-25 

 (little rain) 



„ 11-13 (D) 



„ 10-12(D) 



From this table we see that rain (very light falls are not 

 considered) is accompanied by a decrease in the amount of 

 emanation. There are, however, about an equal number of de- 

 creases as well as increases which are not accompanied by rain. 



(3) Coordinated with barometric changes and rainfall is 

 wind intensity . The next table shows the effect of wind force 

 (wind force is not plotted in the curves on Plate I., but is 

 given in the tables of results, Tables III., IV., V., pp. 10-17). 

 Wind changes of less than two steps on the Beaufort scale are 

 not considered. The letter R again means rain (or snow). 



Table VIII.— Effect of Wind Force. 



1 

 Of an Increase of Wind Force. 



Of a Decrease in Wind Force. 



None. 



Decrease. 



Increase. 



None. 



Decrease. 



Increase. 





Mar. 16-18 

 „ 23-25 (R) 

 „ 29-Ap. 1 (E) 



April 26-29 (E) 



May 4-6 

 „ H-13 

 „ 19-20 

 „ 25-27 (R) 



May 31-June 1 (ft) 



Aug. 17-19 (R) 









Mar. 3-5 

 „ H5-17 



„ 31 -Ap. 2 



May 13-14 



„ 18-19 

 „ 26-28 



Aug. 2-5 



