Pocket sympiesometer, 1839
Pocket sympiesometer, invented by John George Harris Ronketti, in leather covered wooden case, made by Carpenter & Westley, 24 Regent Street, London, 1839
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Mercury barometers needed to have two tubes that were at least 33 inches long, and were generally cumbersome to carry around. To allow for readings of air pressure by a pocket instrument, a much shorter glass tube was doubled back on itself to fit a small case, and the moving agent was a combination of air, spirit and mercury. This example was made by Carpenter and Westley to a design registered by Ronketti in 1839.
- Measurements:
-
overall (closed): 240 mm x 74 mm x 45 mm,
overall (open): 240 mm x 140 mm x 35 mm,
- Materials:
- brass (copper, zinc alloy) , glass , mercury , ivory , wood (unidentified) , leather , paper (fibre product) , silk and wax
- Object Number:
- 1929-962/1
- type:
- sympiesometer
- Image ©
- The Board of Trustees of the Science Museum
