Signedon dial: MILLIAMPERES D.C. / WESTON ELECTRICAL INSTRUMENT CORP., NEWARK, N.J., U.S.A. / MODEL 301 / NO. 1961811
Inscribedbox is labelled: MOD. 301 MA/10 MLLI-AMPS/SQUARE BAKELITE
FunctionA sensitive ammeter for very small currents.
ProvenanceFrom William James Hall, Harvard University.