50 Dr. A. Stoletow on the Magnetizing -Function of 



tiplier, and imparts a deflection to the magnet. The position of 

 equilibrium conditioned by the primary current is observed, 

 as well as the induction-deflection. By a second turning of Cj 

 the magnet, after coming to rest, receives an impulse in the 

 opposite direction. Finally, the same observations are made 

 after the commutator C 2 has been turned and thereby the cur- 

 rent in the entire primary circuit reversed. Let 



a be half the difference between the two positions of equili- 

 brium of the magnet with the two positions of the commu- 

 tator C 2 , 

 A the elongation of the magnet from the then position of 



equilibrium by the induction -shock, 

 T the time of an oscillation of the undamped magnetometer, 

 X the logarithmic decrement of the oscillations when the se- 

 condary wire is closed, 

 m the ratio of the torsion-moment exerted by the multiplier 

 upon the magnet to that proceeding from the roll, the same 

 current passing through both ; 



then the ratio of the induction-shock J to the primary current 

 ij both taken in the same measure, is 



J A T Aarctan!^ 

 — = • — . £"/* A 



i ma tt 



where [x is the modulus of the Briggian logarithms. 



If, instead of observing the first deviations, we wish to employ 

 the multiplication method, A and a are to be calculated, in the 

 known manner, from the consecutive readings and the damping X. 



Therefore, m and T being known (T varies a little, and must 



be determined afresh from time to time), the ratio - can be cal- 

 culated from determinations each time of A, a, X. If, further, 

 the resistance W of the secondary closing is known in absolute 



, , x , ,. E J.W ,. . . 



measure, we nave also the ratio — = — — , which is required for 



the calculation of k. 



The resistances of all the wires of which, in the various ob- 

 servations, the secondary circuit consisted — that is, of the mul- 

 tiplier M (w m ) and all the sections of the second layer of wire 

 (w^, w'ioo; • • •) — were determined in absolute measure by compa- 

 rison according to Wheatstone's method with a British Asso- 

 ciation unit. They were (reduced to 20 o, 4 C.) : — 



w m =2-4758 x 10*°™- m; 1so =2-1150 x 10 101 ™* 



sec. 1M sec. 



w m =074502 „ , t w 20Q =2-6829 „ „ 



^ico = l'4046 „ „ w.' 250 =3-4253 „ „ 



