Accession No
1937
Brief Description
seven mercury-in-glass thermometers, by H. Geissler, German, 1877
Origin
Germany; Bonn
Maker
Geissler, H.
Class
laboratory apparatus; thermometry
Earliest Date
1877
Latest Date
1877
Inscription Date
Material
glass; metal (brass, mercury); rope (string)
Dimensions
1937.1 length 396mm; diameter 10mm 1937.2 length 268mm; diameter 8mm 1937.3 length 255mm; maximum diameter 11mm 1937.4 case length 105mm; breadth 12mm; thickness 12mm 1937.5 length 200mm; diameter 6mm 1937.6 length 208mm; maximum diameter 15mm 1937.7 length 457mm; diameter 9mm
Special Collection
Cavendish collection
Provenance
Transferred from the Cavendish Laboratory, University of Cambridge, from 1974. Purchased by the Cavendish Laboratory in 22/04/1877.
Inscription
‘Centigrade. Dr H. Geissler in Bonn’ (1937.1, 1973.2, 1973.3, 1973.5 and 1973.7)
‘Fahrenheit Dr H. Geissler in Bonn’ (1937.4 and 1937.6)
Description Notes
1937.1: Long-bulb mercurcy in glass Celsius thermometer. Fine bore thermometer set on white glass plate, the whole in a glass jacket. Scale divided 95 - [218], numbered by 5˚, subdivided to 0.2˚. Jacket scratched at top ‘C.L.C. 23’; also paper label with ‘23’ in ink.
1973.2: Short-bulb mercury in glass Celsius thermometer. Fine bore thermometer set on white glass plate, the whole in a glass jacket. Scale divided [87] - 360˚ C, numbered by 10, subdivided to 1 (scale possibly broken at top end). Jacket scratched at top ‘C.L.C. 19’; also paper label with ‘19’ in ink.
1973.3: Long-bulb mercury in glass Celsius thermometer. Fine bore thermometer set on white glass plate, the whole in a glass jacket narrowing to very fine tube at lower end. Brass ferrule cap with suspension point. Scale divided [26.3] - [53]˚C, numbered by 2, subdivided to 0.1. Jacket scratched at top ‘C.L.C. 15’; also remains of paper label with ‘15’ in ink.
1973.4: [THIS THERMOMETER IS MISSING - 26/11/2007, J.N. Earlier catalogue entry lists this object as broken - perhaps removed?] mercury in glass Fahrenheit clinical thermometer. Fine bore thermometer, the overall length being reduced by a loop in the tube (leakage of mercury into jacket) White glass plate. The whole encased in a glass jacket with slight constriction beneath the plate. Brass ferrule cap. Scale divided [91.8] - [114.3]˚ F, numbered by 5˚, subdivided to 0.2˚. Jacket scratched ‘C.L.C. 11’; also paper label with ‘11’ in ink. Brass slip case.
1973.5: Long-bulb mercury in glass Celsius thermometer. Fine bore thermometer set on white glass register plate, the whole in a glass jacket narrowing below the register plate. Scale divided 28 - 50˚ C, numbered by 1˚, subdivided to 0.1˚. Jacket scratched ‘C.L.C. 13’; also paper label with ‘13’ in ink.
1973.6: Long-bulb mercury in glass Fahrenheit thermometer. Fine bore thermometer set on white glass register plate, the whole in a glass jacket narrowing below the register plate; overall length of bore is reduced by a loop. Brass ferrule cap with suspension cord. Scale divided [82] - [113]˚ F, numbered by 5˚, subdivided to 0.2˚. Jacket scratched ‘C.L.C. 4’.
1937.7: Long-bulb mercury in glass Celsius thermometer. Fine bore thermometer set on a white glass register plate, the whole in a glass jacket. Glass suspension loop with red cord. Scale divided [195] - [306.2]˚C, numbered by 5˚, subdivided to 0.2˚.
Condition good (except 1937.2 - fair - and 1937,4 - broken); complete
References
Events
Description
A thermometer is an instrument that measures how hot or cold something is, in other words, its temperature. Most familiar is the "Mercury-in-glass" thermometer, but there are many other kinds.
Many materials expand as they get hotter and contract as they get colder . This expansion and contraction can be used to measure the corresponding changes in temperature. Thus the first useful thermometers were made from a glass bulb full of mercury to which was attached a narrow glass tube. As the bulb is heated a fine thread of mercury expands up the narrow tube. Thermometers, requiring great skill in glass working, were first made by Daniel Fahrenheit of Amsterdam in 1717.
To measure temperature precisely, a numerical scale of "degrees" is needed. To provide this scale two fixed points are chosen, such as melting ice and boiling water. Convenient temperatures are then given to these two fixed points: today melting ice is given a temperature of 0 degrees and boiling water 100 degrees. This is the Celsius or Centigrade scale (although it is quite arbitrary). Fahrenheit himself originally chose the coldest temperature that he could produce (a freezing mixture of ammonium chloride and snow) as 0 degrees and body temperature as 96 degrees. This resulted in the Fahrenheit scale in which the freezing point of water is 32° F and the boiling point of water is 212° F.
01/03/2001
Created by: Chris Lewis on 01/03/2001
FM:42185
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