“Edison cell, type RR. The electrolyte used is caustic soda, the positive element zinc, and the negative element copper oxide. The Edison cell is suitable for large stationary gas engine ignition, ralroad crossing signals, electroplating, fire alarms, telephone cicuits, etc.” -Hawkins, 1917
Hawkins and Staff Hawkins Electrical Guide Number One (New York: Theo. Audel and Company, 1917) 50
1592×2400, 2.1 MiB
679×1024, 304.2 KiB
424×640, 149.8 KiB
212×320, 39.0 KiB