Signedunsigned
InscribedInside mag. support ends marked: N / P;
mag. support & brass back stamped: 1
FunctionConversion of electrical impulses into sound for output by telephone
ProvenanceJefferson Laboratory, Physics Department, Harvard University
Published ReferencesThis instrument is described in:
Thomas G. Hedberg, "Catalogue: Telephones, Phonographs and Related Instruments in The Collection of Historical Scientific Instruments at Harvard University." William Andrewes, Project Director (unpublished manuscript, President and Fellows of Harvard College and Thomas G. Hedberg, 1989. Fifth Draft), p. 83.