An early 20th-Century forecasting aneroid barometer,

An early 20th-Century forecasting aneroid barometer,
by Negretti & Zambra, London, 9303, in a fitted case -- 14.6cm. (5¾in.) wide

See Colour Illustration

The 9.5cm. (3¾in.) diameter barometer has a brass casing, finished to appear gilded, with a scale around the edge of the casing for altitude. The barometer face is graduated 28-31 and has a fine blued-steel needle. There is a secondary instrument also in the case, for use with the barometer for weather forecasting. This comprises a brass disc with a folding table stand attached to the rear, and two volvelles. The inner volvelle bears instructions for use and is dated 1915. There is a narrow aperture marked FORECAST which shows innumerable weather conditions such as FINE BUT POSSIBLE SHOWERS on the volvelle beneath. Also on the second volvelle are rising, falling and steady settings for summer and Winter, which are aligned with a scale on the main disc for wind direction. The central volvelle also aligns with a second scale on the main disc, corresponding to the barometer's reading. The fitted wooden case is lined with green plush and covered in red fabric, with a push-button catch.