The instrument is supported by a wooden tripod frame holding a plate that serves as base for a bell-jar. A faucet connects the plate to an upright iron tube. The latter communicates with an upright wooden tube also attached to the frame. The pump was restored after being damaged in the 1966 Arno flood. This type of mercury pump resembles the one described by Emanuel Swedenborg in his Miscellanea of 1722. The vacuum was obtained by lowering and raising the mercury column in the upright tube by the pumping action of the wooden rod. Resembles item inv. 1530. Provenance: Lorraine collections.