産業機器 - Germany - ルムコルフ誘導コイル。

Two early 20th‑century scientific apparatus items: a Ruhmkorff induction coil mounted on a wooden base with brass fittings and a black coil, manufactured by Gebrüder Bing Nürnberg for physics lessons between 1906 and 1919, measuring 17 × 11 × 10 cm and in good used condition with minor signs of aging and small stains; and a Physikalische Werkstätten Göttingen slider rheostat with a metal coil on a ceramic core, mounted on a wooden base with a sliding contact, produced between 1920 and 1950, dimensions 13.5 × 7.5 × 5.5 cm.