3 6z 



THE POPULAR SCIENCE MONTHLY. 



Although the electrical end is obtained by substituting paste 

 for metallic lead, yet this does not prevent the charging current 

 from attacking the lead frames which hold the paste. These in 

 time are rendered porous, and after a while they break under 



To avoid this, alloys and many secret compo- 



their own weight 



fi 



Plate with Holes of Larger External 

 Diameter. 



Plate with Holes of Larger External 

 Diameter (filled with paste). 



sition metals have been substituted for the lead frames. Even 

 then, the continual change in volume of the paste contained in 

 them twists and warps them so that new plates have to be substi- 

 tuted after a while. No good battery has yet been constructed 

 which can be said to have a reasonably long life. 



From what has been said it will be seen that the electricity 

 which is used for charging an accumulator is apparently used in 



Plate with Holes of Larger Inter- 

 nal Diameter (filled with paste). 



Modern Accumulator. 



the production of oxygen and hydrogen gases. These are made 

 to oxidize one plate and clean up the other. Now, an interesting 

 question arises, whether it would not be more economical to em- 

 ploy gases, which can be more cheaply produced through chemi- 

 cal means. Difficulties, however, arise here, for the oxygen of 



