Wooden box measuring 10 cm x 8 cm x2.5 cm, flips open to expose selenium cell. Cell measures 3.0 cm by 5.0 cm. Stebbins described the Giltay selenium cells he and Brown used in the selenium photometer as “Two wires are wound close together in a…
Model no. 89, no. 18. Box is 8 ¼ x 8 ½ x 12 inches and screwed closed. Unknown date but estimated around 1908. Used with the selenium cell photometer to measure current and with the photoelectric cell photometer. Visible in pictures of transit room. …
The photocell is hand blown glass or quartz. Within in the cell is an alkali metal (lithium, sodium, or potassium) that covers the inside and is a cathode emitting electrons when illuminated. A well insulated wire forming a ring centered in the…
Model 45, No. 32664, in oak box measuring 7 7/8 x 5 3/8 x 7 7/8 inches, with leather handle, 2 scales 0-150, 0-15. Paper label dated November 5, 1926. All hardware is nickel-plated brass. The front panel and meter face…