Small pump mounted vertically on a brass base connected to a thick-walled glass vessel. The vessel is housed in a frame consisting of two wooden pillars supporting a brass cross-piece secured by nuts. There are two pressure gauges, one external, set into the base, the second placed upright inside the vessel. This type of pump produced pressure in the vessel exceeding atmospheric pressure by compressing the air inside the vessel. Made by Nairne & Blunt. Provenance: Lorraine collections.