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 d 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 e=4.891X10- 10 . 



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

 their introduction would change the final value of 6, which as a mat- 



