Page:Popular Science Monthly Volume 38.djvu/376

362 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 their own weight To avoid this, alloys and many secret composition



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 substituted 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



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 employ gases, which can be more cheaply produced through chemical means. Difficulties, however, arise here, for the oxygen of