Antique Mahogany Negretti & Zambra London Barograph with Thermometer : Working

This is a wonderful quality antique barograph which was made by the highly renowned NEGRETTI & ZAMBRA, LONDON and has the rear feature of a thermometer. The case is made from mahogany and has lovely deep bevelled glass to all four sides and the top. The jewelled movement is 8 day which and is complete with it's winding key which is integral with the movement. The barograph is engraved on the base plate 'NEGRETTI & ZAMBRA LONDON '. Then the movement bras the NEGRETTI & ZAMBRA symbol and '529', '446' and '7D'

NEGRETTI & ZAMBRA, LONDON was founded in 1850 when Henry Negretti and Joseph Warren Zambra formed a partnership; the firm would eventually be appointed optical instrument makers to Prince Albert, the Royal Observatory and the British Admiralty. The Company later gained patents to improve on the design and construction of its instruments, and in 1851 gained a patent to make thermometers. 1851 The partners were the only English instrument makers to receive a prize medal for meteorological instruments at the 1851 Great Exhibition. They were appointed instrument makers to the Queen, Greenwich Observatory, and the British Meteorological Society

The barograph takes barometric measurements which in turn are recorded on a paper record sheet which is mounted on a clockwork revolving cylinder, the ink nib draws a line on the chart as the pressure rises and falls. The cylinder makes one full revolution in one week. This barograph also has the rare feature of a thermometer.

The barograph and barometer are in full working order. Although not part of the sale, the barograph comes complete with spare charts and ink.

To wind the barograph firstly the lid is taken of, then the locking nut is taken off which allows the barrel to be lifted off. The winder can then be seen and as such can be wound.

The approximate dimensions are:

- 14 1/4 inches (36 cm) long

- 8 3/4 inches (22 cm) deep.

- 8 1/2 inches (21.5 cm) high.

As you can see from these dimensions the barometer is of fantastic proportions.

CONDITION:

The barograph is in excellent condition and is in full working order. The case and glass are also in excellent condition as can be seen in the photographs just minor marks commensurate with age and use and just some age related marks to the brass. Please study photographs carefully as they form part of the description and condition, as what you view is exactly what you will receive.

ref : barograph a55