細節
A signalling relay
by Siemens & Halske, No. 912, with alpha-numeric dial, two iron magnets and coil on lacquered brass base, on maple plinth -- 13¼in. (33.7cm.) wide
by Siemens & Halske, No. 912, with alpha-numeric dial, two iron magnets and coil on lacquered brass base, on maple plinth -- 13¼in. (33.7cm.) wide