tlie Galvanic Current through Iron. 9 



The influence of the repetition many times of the same ex- 

 periment rarely showed itself so insignificant as in this case. 



10. Instead of the resistance-box, a rectilineal rheostat was 

 employed. The numbers for w and w are expressed in terms 

 of an "arbitrary unit. H= ID ; M = 2D ; n=92. 

 values : — 



W = 6019-81 c ]=+3 . 4 



[w] =6023-2/ L 



100000-i^o 



Mean 



S= 



w n 100000 -iv 



1= +0*00135. 



The total resistance of the rheostat is put equal to 100000 ; 

 the above calculation was necessary, because here equilibrium 

 was restored by shifting a binding-screw. 



11. In experiment 10 the principal current passed in the 

 iron wire from the south to the north pole. The principal 

 current was now sent through in the opposite direction. The 

 mean values found were : — 



[>o] = 6021; [>] = 6024; [>-w ]=+3; S= +0-00122. 



(According to the same reckoning as above.) Here, how- 

 ever, it must be noted, first, that the iron wire with which 

 these two series of experiments were made had already been 

 repeatedly passed through by the current, and, secondly, that, 

 in the calculation of the mean values in 11, the first numbers, 

 deviating, were left out of the account. The complete series, 

 namely, are as follows: — 



10. 



> therefore w constantly > w Q . 



~w [ 



= 6019 1 



IV 



= 6024 



~w ] 



= 6021 



w 



= 6023 



~W Q ~_ 



= 6019 



w 



= 6022 



'w \ 



= 6020 



~w ~ 



= 6024 J 



11. 



"Wq_ 



= 6022 ) 



IV 



= 6020 1 



~W ~ = 



= 6022 1 



~w 



= 6025 1 



\Wq\ 



= 6022 



IV 



= 6024 



w \ 



= 6020 ' 



w 



= 6023 



= _Wq 



= 6020 J 



be c 



iirection c 



10<W Q 



rw>w Q 



The reversal of the direction of the current in the iron has 



