Before the advent of factory-supplied batteries, railroad telegraph and signal maintainers "made battery" in a glass jar, using a piece of zinc, a piece of copper, sulphuric acid, and a bit of oil poured on top to prevent evaporation. These bottles of "Edison Battery Oil" were found about 20 years ago in the Reading RR's signal storage area at Rutherford (Harrisburg), Pa. The shipping carton showed a ship edate of 1945.