194 Prof. H. F.Weber on Electromagnetic and 



The determinations executed according to this third method, 

 of the absolute electromagnetic value of Siemens's mercury 

 unit, have given the following results : — 



1 S. M.U. =0-9536 xlO 10 



„ =0-9552 „ 



„ =0-9526 „ 



„ =0-9579 „ 



„ =0-9565 „ 



The mean value from these experiments amounts to 



1 S. M.U.= 0-9550 xW^ 1 ^). 



V sec. / 



For facility of review, I place the final results for the abso- 

 lute value of the S. M. XL together. We have found the ab- 

 solute electromagnetic value of :— 



1 S. M. U. =0-9545 x 10 10 ( T ^Eh) 



\ sec. / 



from 18 series of experiments, in which the variable currents 

 generated by magneto-induction were employed ; . 



1 S. M. U. =0-9554 x 10 10 (E^M 



\ sec. 



) 



from 24 series of experiments, in which the variable currents 

 called forth by sudden voltaic induction were employed ; and 



1 S. M. U. = 0-9550 x 10 10 (^^M 



\ sec. / 



from 5 series of experiments, in which the heat-production of 

 stationary galvanic currents was used. 

 The general mean, 



1 S. K. U. = 0-9550 xW™^), 



V sec. / 



is only \ per cent, greater than the result found by Messrs. 

 Maxwell, Jenkin, and Stewart. After these results I hold 

 that the questions of the true absolute value of the S. M. U., 

 and whether the British resistance-unit does or does not repre- 

 sent the value asserted, are settled. The true value of S. M. U. 



liesbetween 0-9536 x 10 10 ^^) and 0*9550 x W^^V 



\ sec. J \ sec. ) 



and the British unit represents, neglecting very minute differ- 

 ences possibly still present, the value asserted, 10 10 (- J. 



\ sec. j 



When an observer finds the same result in three different 



