The instrument was bought on 25 March 1739 for Giovanni Poleni’s Cabinet of Physics.

Inventor: Francis Hauksbee, b.1660 -d.1713. Physicist and instrument-maker, was active in London from 1699 to 1713.

Date: 1st quarter 18th century

Description

The air pump is very similar to the model published by Francis Hauksbee in 1709. The pistons in the two cylinders are moved thanks to a handle and a cranking mechanism. The air-pump is still equipped with its original mercury manometer, made of a glass tube. The lower end of the manometer was originally immersed in mercury. A three-way stop-cock is located at the basis of the cylinders. It was quite certainly added later, to replace the original valves placed in the cylinders - we know from the historical inventories that the air pump was actually modified in the eighteenth century. Thanks to the three-ways stop-cock, the cylinders were alternatively connected to the bell jar or to the outside. When a piston was raised, the air of the bell jar was thus sucked under the piston, while it was expelled outside when the piston was lowered. This air pump was among the very first instruments of Padua University Cabinet of Physics. It belonged to Cristino Martinelli, a Venetian patrician who had a keen interest in science. Martinelli died in 1732, and the Venetian Republic bought this device from his heirs in 1739. Poleni describes it in his “Indice delle Macchine”, underlining that “it needs some restauration”, and Simone Stratico, one of Poleni’s successors, wrote in 1778 that it was “out of use […] It was also damaged by a bad craftsman, but it can be repaired: however the cost would be excessive to finally have a bad machine” (Stratico, 1778).

Materials and techniques: wood/brass/iron/bronze

Dimensions: height 115 cm, width 40 cm, depth 60 cm

Related scholars: Giovanni Poleni (b.1683 - d.1761). Professor of Experimental Philosophy at the University of Padua from 1739 to 1761 / Cristino Martinelli (b.1653 - d.1732)

Keywords: mechanics, pneumatics

University of Padua, Museum of the History of Physics

Cat. Number: 1

Exhibitions

• "La curiosità e l'ingegno - Collezionismo scientifico e metodo sperimentale a Padova nel Settecento", Padua, Orto Botanico, May-December 2000
• "Bagliori nel vuoto. Dall'uovo elettrico ai raggi X: elettricità e pneumatica dal Seicento ad oggi", Padua, Orto Botanico, 1 February-30 June 2004
• "Il futuro di Galileo. Scienza e tecnica dal Seicento al Terzo Millennio", Padua, Centro culturale San Gaetano-Altinate, 28 February-28 June 2009

Bibliography

• John Theophilus Desaguliers, Cours de physique expérimentale, 2 vols., Paris, 1751
• Francis Hauksbee, Physico-mechanical experiments, Londra, 1709
• Giovanni Poleni, Indice delle macchine, Biblioteca Nazionale Marciana di Venezia, mss.it., cl. III, 54-55 = 4969-4970, cl. IV, 626 = 5488, 636 = 5497. [Venne redatto da Giovanni Poleni fra il 1740 e il 1761]
• Simone Stratico, Catalogo delle Macchine della Sala di Fisica Sperimentale nell'Università di Padova – 1778, Università di Padova, Dipartimento di Fisica e Astronomia "Galileo Galilei", ms. n. 824