MR. F. K. SMITH ON THE NORMAL WESTON CADMIUM CELL. 



417 



Eight of the American cells and eight of the English cells were compared at 

 the Lal)oratoire Central d'Electricitd under conditions which allowed of an approxi- 

 mation to 1 part in 100,000. The maximum deviation of the eight American cells 

 from their mean was found to be 0-00002 volt, and the difference between this mean 

 and the mean of the Weston cadmium cells of the Laboratoire Central was of the 

 order of '00001 volt. The maximum deviation of the eight English cells was 

 about 00003 volt, and their mean E.M.F. differed from the E.M.F. of the French 

 cells by about O'OOOOl volt. A second set of comparisons, made at Paris in August, 

 confirmed the first measurements on the American cells. 



Dr. BURGESS left four English cells at the Laboratoire Central, and M. JANET, the 

 Director of the Laboratory, has compared these with the French cells, with the 

 following results. 



TABLE VII. 



The cells K 12, K 13, K 14, were set up at the National Physical Laboratory on 

 October 2, 1907, and Mr. AOAR BAUOH kindly took them to M. JANET. The cells 

 H 26, H 28, and H 29 (see p. 402) were set up with pastes which may be very 

 slightly acid. 



Eight of the American cells and eight of the English cells were compared at 

 Berlin, June 20 and June 21, while two American cells and four English cells remain 

 at the Reichsanstalt and have been intercompared from June 20 to September 30, 

 1907. The following statements are extracted from a formal report by Messrs. 

 JAEGER and LINDECK. 



The results of the tests of the Weston cells brought over from America and 

 England are given in Table VIII. Since only the cells 183 and 184 from America, 

 and H 29, P 55, C 117, and C 12 from England, have been left in Charlottenburg, 



VOL. ccvn. A. 3 H 



