Beschreibung:

A VICTORIAN OAK MERCURY 'ADMIRAL FITZROY'S STORM BAROMETER' Negretti and Zambra, London, circa 1870 The arched bevel-glazed single ceramic Vernier scale to the right of the large bore mercury tube calibrated in barometric inches and with the usual observations, the lower margins annotated ADD ONE TENTH FOR, EACH HUNDRED, FEET ABOVE, THE SEA over PATENT No. 2809 and with signature NEGRETTI & ZAMBRA, INSTRUMENT MAKERS, TO HER MAJESTY, HOLBORN VIADUCT E.C., 122 REGENT ST. W, & 45 CORNHILL E.C., LONDON to upper margin, the apex of the arch further inscribed ADMIRAL FITZROY'S, STORM BAROMETER., the trunk with Vernier setting squares to throat above applied glazed mercury tube Fahrenheit scale thermometer further signed NEGRETTI & ZAMBRA, LONDON to upper margin and with ogee moulded crests to the upper and lower rails, the base with rectangular ogee moulded cistern cover over conforming base moulding with level adjustment screw to underside. 102cm (40ins) high. Provenance: The Selwyn Demmy Collection. The firm of Negretti & Zambra are recorded in Banfield, Edwin BAROMETER MAKERS AND RETAILERS 1660-1900 as being established in 1850 when a partnership between Enrico Negretti and Joseph Warren Zambra was formed. The firm became one of the most prolific makers of scientific instruments and continued trading well into the 20th century. The current lot is an example of a Fishery or Sea Coast storm barometer devised by Admiral Robert Fitzroy in the 1860`s to aid mariners in the forecasting of storms. Interestingly the scale only incorporates one Vernier scale (rather than usual the double scale) hence recording daily change in barometric pressure would have had to be done by taking notes rather than using the second scale. Fitzroy lobbied the Board of Trade resulting in this type of barometer being supplied (at public expense) to many coastal communities for display in a prominent public space. In addition to this The Royal Lifeboat Institution installed these barometers into each of its stations and the Duke of Northumberland (in association with the British Meteorological Society) erected several on the coast of Northumberland. By 1864 over 80 barometers had been installed by the Board of Trade and a further 14 by the Duke of Northumberland with their usefulness fully appreciated in Fitzroy's Meteorological Office Report published that year. Condition Report: The tube is filled with no apparent airlocks and both Vernier slide is fully operational. The scales have some slight overall crazing and the left panel of the scale has a small hairline crack across the top right hand corner. The thermometer is in good working condition however the scale has overall stained crazing. The case is in good original condition with only minor bumps, scuffs and other age related blemishes. Condition Report Disclaimer