STORAGE BATTERIES. 249 



than the negative grid and therefore a greater number of cross- 

 ribs is left on the positive grid than on the negative grid. 



The grids of the stationary type of storage cell of the Electric 

 Storage Battery Company, which is known as the " Chloride " 

 cell, are shown in Fig. 145. This figure also shows one of the 

 thin corrugated wooden plates which are used as separators be- 

 tween the grids. The positive grid of this cell is a plate of lead- 

 antimony alloy cast with numerous holes into which circular 

 plugs or coils of pure corrugated lead tape are 'placed. These 

 plugs are then converted into active material by an accelerated 

 Plante process. The negative grid is made by, inserting small 



Positive grids. Negative grids. 



Fig. 145. 



blocks of active material into holes in a grid of pure lead. This 

 grid is made in two halves which are pressed together over the 

 blocks of active material and riveted together under pressure. 



The grids of the portable type of storage cell of the Electric 

 Storage Battery Company, which is known as the " Exide" cell, 

 are grids cast of a lead-antimony alloy. The interstices in the 

 positive grid are filled with a paste of red lead and sulphuric 

 acid, and the interstices of the negative grids are filled with a 

 paste of litharge and sulphuric acid. 



Storage battery grids made by the Plante process are usually 

 much heavier than Faure grids of the same capacity, but the 



