Accession No
1378
Brief Description
air pump, 1/2 19th C
Origin
Maker
Class
physics
Earliest Date
1800
Latest Date
1850
Inscription Date
Material
wood (mahogany and one other); metal (brass)
Dimensions
length 480mm; breadth 250mm; height 395mm
Special Collection
Provenance
Presumed transferred from the Cavendish Laboratory, University of Cambridge.
Inscription
[maker’s plate is missing from front of pump]
Description Notes
Rectangular mahogany base with four feet (one missing) and brass securing bracket beneath. Two brass discs connected to pump, one for bell jar. Knurled screw stopper at front. Two brass columns with brass knobs and wooden cross piece support pump, which consists of 2 brass cylinders and pistons with rack and pinion action, moved by brass crank with turned wooden handle, crank secured by knurled brass screw.
Condition fair (brass very tarnished, maker’s plate missing); complete.
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:44657
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