05/17/1880 Upton, Francis Robbins -- Technical Notes and Drawings
(Edison, Thomas Alva) Sockets, fuses, meters, and other interior elements
[N048]  Notebook Series -- Menlo Park Notebooks: Notebook #48 N-79-07-05 (1879-1880)
[N048085; TAEM 33:173]
Courtesy of Thomas Edison National Historical Park.