Air pump, Nollet type

This single-barrel air pump resembles the one described by Jean-Antoine Nollet in Leçons de physique expérimentale (Paris, 1743-1748). The pump is mounted on a wooden tripod, ornately carved with period motifs. In the vertical barrel runs a piston moved by a crank carrying a toothed pinion that meshes with a rack. A large brass faucet connects the barrel with the plate above it, which supports a glass bell-jar (not original). Two brass supports attached to the tube entering the plate are fitted with pinchers carrying two butterfly screws. They were used to conduct experiments in the rarefied air inside the bell-jar. In the pump described by Nollet, the piston is operated by means of a simple stirrup. Provenance: Lorraine collections.