Accession No
2039
Brief Description
air pump, by the Pulsometer Engineering company, English, 1/2 20th C
Origin
9 Elms Iron Works; Reading; England
Maker
Pulsometer engineering company
Class
physics
Earliest Date
1900
Latest Date
1950
Inscription Date
Material
metal (cast iron, brass); wood; plastic (synthetic rubber); oil
Dimensions
length 435mm; breadth 400mm; height 510mm
Special Collection
Cavendish collection
Provenance
Transferred from Cavendish Laboratory, University of Cambridge, 1974.
Inscription
‘PULSOMETER ENGG CO LTD
9 ELMS IRON
WORKS
READING’ (plate on base)
Description Notes
Vacuum / air pump, by the Pulsometer Engineering company, English, 1/2 20th C.
Rectangular black-painted cast iron base carries brass piston and iron standard which carries arm which moves inner part of piston; driven by fly wheel with wooden handle. Stop cock on piston, also short pipe with short length of rubber tubing.
Condition fair; 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:44781
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