1838] 



WRITINGS OF JOSEPH HENRY. 



129 



The induction from coil No. 3 to helix No. 1 produces an 

 intensity current, and from helix No. 2 to coil No. 4 a quan- 

 tity current. 



Fia. 9. — a coil No. 1, b coil No. 2, c coil No. 3, d helix No. 1, c helix No. 2 

 and 3,/ coil No. 4, and g magnetizing spiral. 



88. If the ends of coil No. 2, as in the arrangement of Fig. 

 8, be united to helix No. 1 instead of coil No. 3, no shocks 

 can be obtained ; the quantity current of coil No. 2 appears 

 not to be of sufficient intensity to pass through the wire of 

 the long helix. 



89. Also, no shocks can be obtained from the handles 

 attached to helix No. 2, in the arrangement exhibited in Fig. 



Fig. 10. — a coil No. 1, b helix No. 1, c coil No. 3, and d helix No. 3. 



10. In this case the quantity of electricity in the current 

 from the helix appears to be too small to produce any effect, 

 unless its power is multiplied by passing it through a con- 

 ductor of many spires. 



90. The next inquiry was in reference to the direction of 

 these currents, and this appeared important in connection 

 with the nature of the action. The experiments of Dr. Fara- 

 day would render it probable, that at the beginning and 

 ending of the secondary current, its induction on an adjacent 

 wire is in contrary directions, as is shown to be the case in 

 the primary current. But the whole action of a secondary 

 current is so instantaneous, that the inductive effects at the 

 9 



