and a new Secondary Battery. 



59 



connexion with the exciting battery. Eleven pairs of brass springs 

 (A Y B,), (A 2 B 2 ), , fixed to the ebonite stand and pro- 

 vided with screws for the necessary connexions, press against 

 the cylinder in a direction transverse to its axis. Two narrow 

 brass plates, C and D, are fixed to the cylinder on opposite sides, 

 and are respectively in metallic communication with the supports 

 N and P. In the position of the cylinder shown in this figure, 

 these two plates are in a horizontal plane ; and it will be seen 

 that they do not extend the whole length of the cylinder, but 

 that plate C is just clear of the spring A u , and the plate D 

 clear of the spring B 1; which springs are connected with the 

 wires T and S respectively, through which the secondary dis- 

 charge is to be taken. Between the letters H and H are seen 

 eleven white circles, which represent the extremities of the same 

 number of brass rods passing across the axis of the cylinder and 

 extending slightly beyond its surface on each side ; in the above- 

 mentioned position of the cylinder the rods are vertical. The 

 forty cells being arranged in ten sets of four each, let us call 

 the right-hand terminal of each set Rj, R 2 , . . . R 10 in order, 

 and the left-hand terminals, L lf L 2 , 

 Then A x and R„ A 2 and R 2 , A, 



. L T0 , in the same order. 



id R 



10' 



and B 2 and L p 



B 3 and L 2 , . . . . B u and L l0 are respectively connected, as shown 

 in the figure ; and P and N are connected with the positive and 

 negative poles respectively of the exciting battery, which con- 

 sisted of five Grove cells. When the plates C and D are in a 

 horizontal plane, the springs A 1? A 2 , .... A 10 are pressing 

 against the plate C, and therefore all the right-hand terminals, 



Rm R 2 



R )0 , are connected with the negative pole of the 



Grove battery; and similarly the left-hand terminals L x . . . . L, 

 through the springs B 2 . . . . B n and the plate D, are connected 

 with the positive pole, and the secondary batteryis being charged. 

 Let the cylinder be now turned through 90° into the position 

 shown in fig. 3, which (having the same lettering as fig. 2) re- 



Fig. 3. 

 c 



