09/10/1878 [Supplied year, month, and day] Edison, Thomas Alva -- Patents -- Caveats
Incandescent lamp
[NE1695]  Notebook Series -- Experimental Researches: Cat. 997 Vol. 5 (1875-1877, 1878-1879)
[NE1695049; TAEM 3:376]
Courtesy of Thomas Edison National Historical Park.