Sisson Theodolite

Description
The basic form of this theodolite–with the telescope mounted on the open side of a semicircle–was introduced by Jonathan Sisson in London in 1737. In 1758 Edmund Stone described Sisson's theodolite as "certainly the best, most complete, handsome, and well designed Instrument possible." In this example, the vernier for the horizontal circle is moved by rack and pinion, and reads to 12 minutes. The front side of the vertical arc also reads by vernier to 12 minutes. The back side has a logarithmic scale. The "J. Sisson, London" signature refers to Jonathan Sisson (about 1690–1749) or his son, Jeremiah Sisson (1720–1783).
Ref: William Gardiner, Practical Surveying (London, 1737).
N. Bion, Construction and Use of Mathematical Instruments, English translation by Edmund Stone (London, 1758).
Location
Currently not on view
maker
Sisson, Jonathan
place made
United Kingdom: England, London
Measurements
overall: 9 in; 22.86 cm
horizontal circle: 5 in; 12.7 cm
telescope: 4 7/8 in; 12.3825 cm
overall in case: 10 13/16 in x 8 1/8 in x 7 in; 27.46375 cm x 20.6375 cm x 17.78 cm
ID Number
PH.328868
catalog number
328868
accession number
278000
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center

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