246 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1910. 



Table IV. — Negative drop No. 8. 



[Distance between cross hairs = 1.033 cm. Temperature=20° C] 



Table V.- — "Negative drop No. 2. 



[Distance between cross hairs= 1.005 em. Temperature=24.3° C] 



Table VI. — Positive drop No. 15. 

 [Distance between cross hairs=1.033 cm. Temperature=20° C] 



The drops shown in Tables III and IV were of almost the same 

 size as is seen from the closeness of the values of the two velocities 

 under gravity, and although the field strength was in one case 

 double that in the other the values of e 1 obtained are almost iden- 



