34G APPENDIX. 



the lever is put down (arrangement of key to break 

 6 a 



Fio. 2. 



the current) ; lastly, if the wires from the battery are 

 connected with a and b respectively, and the wires 

 of the electrodes with a and c respectively, then the 

 current passes across the key until the end as of the 

 lever is pressed down when the current is thrown 

 into the electrodes (arrangement of key for short- 

 circuiting the current) 



da Sois Reymoud's Indnctiou Machine. This is 



shewn at J), Fig. 1. The screws at the top of the 

 machine are connected with the ends of the wire 

 forming the primary coilj consequently, when the bat- 

 tery wires are connected with these screws, each break 

 and each make of the circuit produces an induction 

 current in the secondary coil ; the make and break 

 can be most simply effected by means of a key 

 placed in the primary circuit and arranged to break 

 the current (cp. above); in the text this is called the 

 arrangement for single induction shocks. 



When -the wires from the battery are connected with 



