Novel Mode of Discharging a Leyden Battery. 



419 



several jars are arranged as shown in fig. \ , to be charged ; but 

 part of a revolution given to each spindle will bring them into 

 series as show in fig, 2, when the discharge will take place be- 

 tween A and B. 



Fig. 1. 



Fig. 2. 



as 



w 



That the multiplication of the intensity will actually take place 



7 J J ^—p,--. ____ ± 



na of a single jar. The general principle concerned, is that if a 

 ball N be connected with the outer coating of a charged jar and 

 a ball P with the inner coating, the difference between the quan- 

 tities* of free electricity in the balls N and P, is constant, or ap- 

 proximately so, though the quantities themselves be varied. 



Thus, let us suppose the jar to be charged to such a degree that 

 with N in its natural state, P is found by the electrometer to have 

 a quantity of free electricity denoted by a. Then, the jar being 

 insulated, it is known that if a quantity q of free electricity be 

 given to N, a corresponding additional quantity is set free from 

 the inner coating of the jar in consequence of the diminished 

 induction of the outer coating, and thus P will exhibit approxi- 

 mately, and probably exactly, the quantity q+a of free electricity. 

 Hence, if many other jars be also charged to the same degree, 

 and connected in a series with the outer coating of the first in 

 connection with the earth, the P of the first jar must have the 

 quantity a of free electricity, the second jar having its N = a must 

 have its P~ 2 a, and the third jar having its N = 2 a must have 



its P = 3 a, &c. 



" We have thus," says Mr. Mac Gregor, "a new feature intro- 

 duced into our manipulation of Franklin electricity — the simul- 

 taneous change in position of each jar of the battery ; and whilst 

 its first results enable the electrician to exhibit a disruptive spark 

 of great power, we can set no limits to the expectations we may 

 indulge in from its full development," 



♦The word quantity in this connection is not u d in its more common e rse, but 

 is adopted as being best suited to my present purpose. 1 mean by it t.]je quantity 



of free electricity ib a unit of surface of the ball N or P. In this sense the quan- 

 tity of free electricity is a n ware of the rn tensity or rather tension. 



