Accession No

2391

Brief Description

air pump, by Lerebours et Secretan, French, 1845–1855

Origin

France; Paris

Maker

Lerebours et Secretan

Class

physics

Earliest Date

1845

Latest Date

1855

Inscription Date

Material

metal (brass, iron, white metal); glass; wood (cork, two others)

Dimensions

length 570mm; breadth 290mm; height 550mm

Special Collection

Provenance

Historical Technology Inc., 6 Mugford Street, Marblehead, Massachusetts 01495, USA, 1978.

Inscription

‘LEREBOURS & SECRETAN
À PARIS’ (front plate)

Description Notes

Vacuum / air pump by Lerebours & Secretan, French, 1845–1855.

Four turned brass columns support brass base plate. Flat-headed screw stopper at front. Double glass cylinders and white metal pistons with brass rack and pinion action operated by long centrally-pivoted iron crank with wooden grip at each end. Vacuum chamber consists of glass cylinder set on cork seal; brass topped. Between the cylinders and the vacuum chamber is a space for mounting a manometer (missing, but stop-cock still present).

Condition good; incomplete (manometer tube missing).

References

Events

Description
In 1647, Otto von Guerricke of Magdeburg invented the first vacuum pump. Guerricke was a physicist, engineer, and natural philosopher. His intention in creating the vacuum pump was to study vacuums and the role of air in combustion and respiration.

The vacuum pump is in principle a relatively simple instrument. As the handle is turned the pump moves up and down and the air in the bell jar is evacuated and a partial vacuum is created.

A perfect vacuum is a space with no matter in it. However, a perfect vacuum has never been obtained, the most complete man made vacuum had approximately 100,000 gas molecules cc, compared to 30 billion billion in air at sea level. It is estimated that in space there is roughly one molecule per cubic meter.

A famous early demonstration of a vacuum was that carried out by Otto von Guerricke in Magdeburg. A vacuum pump evacuated air from the inside of two hemispheres that had been placed open edge to open edge. Two teams of eight horses were then attached to the hemisphere handles but failed to pull apart the “Magdeburg” hemispheres.

Created by: Boris Jardine

FM:44719