A very unusual carved walnut case aneroid barometer. 222101.

This decorative wheel or banjo barometer features a carved walnut case and an aneroid barometer.

Aneroid barometers do not use liquid to measure air pressure. Instead, the subtle pressure changes in atmospheric conditions affect a series of vacuum capsules and, through springs, register this movement on the circle face at the bottom of the case. The main feature of the display is porcelain and is three-dimensional. The white porcelain face plate features black graphics. This printed information is standard for the form. The center displays some of the inner workings of the instrument. The aneroid barometer was invented in 1844 by the French scientist Lucien Vidi. When using a barometer, two hands are helpful. The first is, of course, fitted to the instrument and provides a current reading. This hand is usually the larger of the two. In this case, a second hand is fitted to the center of the glass that protects the dial. This brass hand is a marker and manually adjusts to mark the position of the other hand each time the instrument is viewed. 

The case is constructed in walnut and has been recently cleaned. The front is embellished with well-executed carvings throughout. In the neck is a red alcohol thermometer. The engraved brass scale is in Fahrenheit. The lower display is framed in a brass bezel. The protected glass features a beveled edge.

This working instrument was made circa 1890. It has been recently serviced. 

Dimensions in inches: 40 long, 12.5 wide, and 3.75 deep.

Inventory number 222101.