WOLLASTON'S BATTERY. 



31 



touch and be soldered to the zinc plate z. For this arrangement, 

 the wooden trough was divided, by plates of glass or varnished 

 wood, into as many cells as there were pairs of zinc and copper. The 

 cells being filled with the 

 acid, or exciting solution, 

 the metals were then placed 

 into them in such a manner 

 that each pair of zinc and 

 copper plates had a partition 

 between. By this arrange- 

 ment the zinc of one pair 

 faced the copper of the next 

 pair in the cell, as shown 

 in figures 6 and 7. The 

 former represents the plates 

 immersed in the solution; 

 the latter, the plates sus- 

 pended on a rack over the 

 solution. This arrangement 

 was termed Babington's 

 Battery. 



woiiaston's Battery. Although we have spoken of the great value 

 of amalgamated zinc for batteries, still at the period when the 

 arrangement just described was introduced, amalgamation was not 

 known ; and the zinc plates were, therefore, always liable to be 

 destroyed by the acid. 

 It was, consequently, 

 of importance that no 

 zinc should be ex- 

 posed to the action 

 of the acid that was 

 not calclulated to 

 give electricity, as the 

 energy of each pair of plates depends upon the extent of surface of 

 the two metals exactly opposite to each other. It will be evident that 

 in Babington's arrangement only one side of the zinc was effective 

 in giving electricity, while both sides were exposed to the action of 

 the acid. To obviate this defect, Dr. Wollaston caused the copper 

 plate to surround the zinc, by which the whole surface of the zinc 

 exposed to the acid was made effective in producing electricity, and 

 thereby doubling its quantity without further cost. The accom- 

 panying figure (fig. 8) shows the manner in which this battery was 

 originally constructed. 



This improvement, if we except several modifications of construc- 

 tion for the facility of taking the plates asunder for cleaning, &c., 

 did all for this kind of battery that could be done. 



