

Figure 8. — Fuller's trough battery, a Daniell cell battery that was used in the 

 early days of British telegraphy. From R. Wormell, Electricity in the Service 

 of Man, London and New York, 1886, p. 397. 



called the "intensity of the electrical force" (that 

 is, the voltage) /z-fold over that produced by a single 

 pair of electrodes, but the quantity of electricity 

 (that is, the current) was the same whether the pile 

 had one pair or n pairs. Davy argued that the 

 intensity of electricity increased with the number of 

 pairs and the quantity increased with the area of 

 these pairs. 1" In 1815 J. G. Children '' published the 

 results of a number of experiments made to prove 

 Davy's hypothesis. He improved the trough battery 

 by applying a suggestion by William Wollaston to 

 increase the area of one electrode by folding it into a 

 L) -shape about the other (fig. 12). Two years later 

 Hans Oersted ^^ reported he had increased the effec- 

 tive area of a battery by replacing the wooden trough 

 with a copper one (fig. 1 3) . This copper trough served 

 as one electrode; the electrodes of the other metal were 

 placed in the trough. Such a design greatly increased 

 the heating and sparking power of the battery. 



■' Humphrey Davy, "On Some Chemical Agencies of Elec- 

 tricity," Philosophical Transactions, 1807, vol. 97, pp. 1-56. 



" John G. Children, "An Account of Some Experiments with 

 a Large Voltaic Battery," Philosophical Transactions, 1815, vol. 

 105, pp. 363-374. 



" Hans C. Oersted, "Bemerkungen hinsichtlich auf Con- 

 tactelektrizitat," Journal Jiir Chemie und Physik (hereinafter 

 referred to as Schweigger's Jo^/rna/) , 1817, vol. 20, pp. 205-212. 



Figure 9. — Pepys' trough battery. From Plulo- 

 sophical Magazine, 1803, vol. 15, pi. i. 



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