Air barometer or "sympiesometer", 1858.

Made:
1858 in London
maker:
L Casella and Company

Sympiesometer with 9-inch ivory scale, in case, by L. Casella, 1858.

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 L Casella.

Details

Category:
Meteorology
Object Number:
1923-409
Materials:
bone, glass, leatherette, mercury, silk, spirit and velvet
Measurements:
overall width and length: 6 x 24.5 cm
type:
sympiesometer and sympiesometers
taxonomy:
  • furnishing and equipment
  • measuring device - instrument
  • barometer
credit:
C F Casella & Company