A late 19th century Wiedemann's-pattern Aperiodic galvanometer, the mirror suspended above the upper pair of coils supported on a limb by twin brass columns, with two high resistance and two low resistance coils on ebonised base with three levelling screws - 14½ in. (36.8cm.) wide, although unsigned, the construction of this instrument is similar to others by M. Hipp & Co. Nuremburg; and a mirror galvanometer by Siemens & Halske signed on the upper plate and No. 6045, the cylindrical glass cover missing - 14¼in. (36.2cm.) high (2)