ZINC ARC LAMPE&MP 94.022 Photo Electric Cells no date Dr. Harvey C. Rentschler, director of Research, Westinghouse Lamp Company, experimenting with a Hot Cathode Positive Column Zinc Arc Lamp. It is a laboratory source of red and blue light and produced by passing a current through a mixture of argon gas and zinc vapor. The predominating color of the light is red. Original Caption by Science Service |