Case for compensated barometer

Maker T Wheeler Scientific Instruments Ltd

Datec 1930s

Object number00028678

NameCase

MediumCardboard, cloth, leather, cotton, metal

DimensionsOverall: 72 x 153 x 72 mm, 0.2 kg

ClassificationsTools and equipment

Credit LineANMM Collection Gift from Dorothy Sharp

Terms

DescriptionThis circular leather case stores a compensated barometer which was manufactured by T Wheeler Scientific Instruments Ltd in the 1930s.HistoryThe basic cause of weather lies in the property of a gas to rise when heated. As air is a gas, when it is warmed by the sun or by a large hot area like a desert, it rises, producing an area of low pressure. Colder, denser, higher pressure air from the surrounding area rushes in to take its place causing wind. This action causes variations in the atmospheric pressure at sea level. To the navigator, the atmospheric pressure in the ship's vicinity is the most important guide to the likely behaviour of the weather in the immediate future, and a barometer is one of the most accurate means of studying this pressure change. SignificanceThis case is significant in relation to the compensated barometer it stores. First patented in France in the 1840s, barometers are an early example of weather gauges used by ship's master, and they remain an essential instrument for mariners today.