Astatic Galvanometer, by Ruhmkorff, Paris, c. 1850

Varnished rectangular wooden tray with four shallow feet and five round divets. Round copper alloy base, with three feet and a dial coming out of the side, supporting a copper disk with white metal edge with a scale on top of a bone(?) structure wrapped with wire. Two poles supporting a brace and dial. Cylindrical glass case, with a hole on top and copper alloy band, sits on top. Bone(?) strip extending from base with two copper alloy dials, each with a green textile-coated coiled wire connected to a metal and bone(?) probe.