Accession No
2333
Brief Description
air pump, by Nairne and Blunt, English, c. 1780
Origin
England; London
Maker
Nairne and Blunt
Class
physics
Earliest Date
1780
Latest Date
1780
Inscription Date
Material
wood (at least 2 types); metal (brass); ivory
Dimensions
length 660mm; breadth 410mm; height 1150mm
Special Collection
Provenance
Purchased from Harriet Wynter, London, England, 14/11/1977. purchased with grant-in-aid from the Science Museum (PRISM).
Inscription
Description Notes
Vacuum / air pump by Nairne & Blunt, English, c. 1780.
Rectangular wooden table on which is mounted an air pump with the single brass piston passing down below the level of the table. Two turned wooden pillars support the brass rack and pinion of the pump; brass crank with wooden handle. Tube from pump passes up through another turned wooden pillar to a brass disc on which is mounted a pair of Magdeburg hemispheres. Ivory scale set horizontally behind rack and pinion, divided [0] - [5.5], numbered by 1, subdivided to 1/16. Top cross brace of compression frame is set on crossing brace of table near floor.
Condition fair (unpleasant lacquer on brass); incomplete (piston rod, compression chamber and pillars of the compression screw frame are 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:44723
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