252 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1910. 



The next to the last column of Table XIV gives the results of this 

 computation of e for all of the observations recorded in Table XIII 



Table XIV, 



Mean e=4.901 



Six months after the original work on this table was done the laboratory obtained a 

 very reliable Weston laboratory standard voltmeter which made it possible to obtain a 

 more perfect calibration curve of the Kelvin and White electrostatic instrument than 

 had been made at first. With the aid of this new calibration curve every value of Ci in 

 the above table was recomputed, with the result that the final value of e was reduced 

 0.06 per cent. Furthermore, in the computation of the above table the m of equation 

 (1) was through oversight treated as the real mass instead of as the apparent mass. 

 This necessitates a further reduction of e amounting to 0.14 per cent, so that the most 

 reliable value obtainable from the work thus far done is 6=4.891X10-1". 



except the first four and the last four. These are omitted not because 

 their introduction would change the final value of e, which as a mat- 



