Pocket aneroid barometer owned by Wallis James Dalgarno

Datebefore 1933

Object number00029033

NameBarometer

MediumMetal: brass, glass, mercury

DimensionsOverall: 68 x 15 x 50 mm, 0.1 kg

ClassificationsTools and equipment

Credit LineANMM Collection Gift from Izetta McKimm

Terms

DescriptionA pocket aneroid (fluidless/dial) barometer owned by Wallis James Dalgarno. An aneroid barometer is used to measure atmospheric pressure which assists in predicting short term changes in the weather. It does not use mercury but rather an internal sealed, air-tight metal box that flexes inwards or outwards depending on the rising or falling of the external air pressure. A metal spring is attached to the box and reacts to the movement which in turn is reflected by an attached pointer indicating the results on a calibrated dial that can be read instantly. HistoryThe concept of a fluidless barometer was first proposed by Gottfried Willhelm Leibniz in 1698, but the technology did not exist for him to take his idea further. It was not until 1843 that the French scientist Lucien Vidie invented the aneroid barometer. Although beginning his career as a lawyer, Vidie's real interest was in engineering. Coming through the Industrial Revolution when steam powered machines, ships and trains were more prolific, Vidie became particularly interested in pressure measuring instruments or barometers. He became focused on inventing a fluidess baroometer, or one that did not use mercury. Vidie invested much of his personal wealth into the venture and came up with the aneroid barometer which he patented in 1843. SignificanceThis aneroid barometer is not specifically a nautical instrument yet a useful thing that a yachtsman might have - a yachtsman who would not want to clutter the cabin with a big barometer on a small yacht. Useful to warn of cyclone etc if sailing in the tropics .