135 



E 



Then _Jl = , and if the co-ordi- 



dx L 



R 



nates x y represented current and time 



E 



_ r\ 



respectively, — = , or L — 4- C 



d t L d t 



R 



R = E, the well-known equation of a 

 single electric circuit. Thus, by means 

 of the integrator, any curve of electro- 

 motive force being given, it was possible 

 to draw the curve of the current. He 

 had further designed machiues which it 

 would take too long to describe, in which 

 with two circuits, given the coefficients 

 of self-induction, the coefficient of mutual 

 induction, and the resistances, with a 

 given curve representing the primary 

 electromotive force, the curve of primary 

 current, the curve of secondary electro- 

 motive force, and the curve of secondary 

 current could be deduced ; and all the 

 curves, their shapes, their retardation, 

 and everything about them. 



