Signedunsigned
Inscribedraised letters on right block: ON;
on right block: 50 M.V.
raised letters on left block: 100 / AMP;
on metal strip: PAT MAY 16 [illegible]
painted on metal strip: 33
FunctionAccording to card, the shut is pivoted with bolts rather than wing bolts for current conductors, which would indicate it was used with a switchboard meter.
ProvenanceFrom the Jefferson Physical Laboratory, Harvard University. Was used for teaching Physics 3 class; and from Pierce Hall, Engineering School, Harvard University.