THE STORAGE OF ELECTRICITY. 



361 



higher oxide, and on the other plate transformed into metallic 

 sponge. This idea of Faure was an excellent one, and is at the 

 foundation of the construction of all the commercial lead accumu- 

 lators. The percent- 

 age of energy recov- 

 ered by discharge 

 was greatly increased. 

 His method of keep- 

 ing the paste in place 

 by felts was, however, 

 soon abandoned, be- 

 cause fine lead needles 

 soon filled up the in- 

 terstices of the felt, 

 and thus made a me- 

 tallic connection be- 

 tween the electrodes. 

 Holes were then 

 punched in the lead 



Reynier's Plaits (un- 

 charged). 



Eeynier's Plaits (charged). 



plates and the paste pressed into them. A large number of the 

 patents recently issued for accumulators refer to methods of 

 making these holes and pressing in the paste, or to the shape of 

 the holes themselves after they have been punched. The shapes 

 vary from a slight depression on the surface to a hole completely 



Eeynier's Modified Plaits (uncharged). 



Reynier's Modified Acctmulator 

 (charged). 



through the plate, and even further, to a hollow plate, with small 

 openings leading to the surface. A great deal depends upon this 

 shape, for the paste changes its volume during the process of 

 charging and discharging, the same as the metallic lead does, and 

 it would tend to loosen itself from some shaped openings and fall 

 to the bottom of the cell, while in others it would tend to tighten 

 itself, and thus provide a better contact. 



