208 Memoir on the Torpedo as imitated by electricity 



of the torpedo are not produced by electricity; but only that the battery 

 I used is not large enough. For we may safely conclude, from the experi- 

 ments mentioned in Arts. 402, 406, 407, that the greater the battery is, 

 the less space of air, or the fewer links of a chain, will a shock of a given 

 strength pass across. For greater certainty, however, I tried, whether if 

 the whole battery and a single row of it were successively charged to such 

 a degree, that the shock of each should be of the same strength when 

 received through the torpedo in the usual manner, that of the whole 

 battery would be unable to pass through so many links of a chain as that 

 of a single row*. In order to which I made the following machine f. 



433] GM, Fig. 5, is a piece of dry wood; Ff, Ee, Dd, Cc, Bb, and Aa, 

 are pieces of brass wire fastened to it, and turned up at bottom into the 



Fig. 5- 



form of a hook, on which is hung a small brass chain, as in the figure, so 

 as to form five loops, each loop consisting of five links; the part G is 

 covered with tinfoil, which is made to communicate with the wire Aa. 

 If I held this piece of wood in one hand, with my thumb on either of the 

 wires Ff, Ee, &c. and applied the part G to one surface of an electric 

 organ, while with a spoon, held in the other hand, I touched the opposite 

 surface, I received a shock, provided the battery was charged high enough, 

 the electricity passing through all that part of the chain between Aa, 

 and my thumb; so that I could make the shock pass through more or 

 fewer loops, according to which wire my thumb was placed on; but if 

 the charge was too weak to force a passage through the chain, I felt no 

 shock, as the wood was too dry to convey any sensible quantity of elec- 

 tricity. The event of the experiment was, that if I charged the whole 

 battery to such a degree that the shock would but just pass through two 

 loops of the machine, and then charged a single row to such a degree as 

 appeared, on trial, just sufficient to give a shock of the same strength as 

 the former, it passed through all five loops ; whether it would have passed 

 through more I cannot tell. If, on the other hand, I gave such a charge 

 to the whole battery, and also to the single row, as was just sufficient to 

 force a passage through two loops of the chain, the shock with the whole 

 battery was much stronger than that with the single row. 



434] It must be observed, that in the foregoing machine, each loop 

 consisted of the same number of links, and the links of each loop were 

 stretched by the same weight ; so that it required no more force to impel 



* The battery, as was before said, was divided into seven rows, each of which 

 could be used separately. j [Arts. 605, 607.] 



