05/09/1876 Batchelor, Charles to Batchelor, Thomas Hatch
Patent assignments, licenses, and royalties; Research and development; Electric pen and mimeograph
[MBLB1]  Special Collections Series -- Charles Batchelor Collection -- Letterbooks: Cat. 1238 (1875-1878)
[MBLB1051; TAEM 93:63]
Courtesy of Thomas Edison National Historical Park.