Antique 1905 wood cased Negretti & Zambra London

Antique 1905 wood cased Negretti & Zambra London Six's maximum and minimum thermometer.

Six's maximum and minimum thermometer is a registering thermometer which can record the maximum and minimum temperatures reached over a period of time, for example 24 hours. It is used to record the extremes of temperature at a location, for instance in meteorology and horticulture. It was invented by the British scientist James Six, in 1780, the same basic design remains in use.

Negretti and Zambra (active 1850 – c. 1999) was a company that produced scientific and optical instruments and also operated a photographic studio based in London.

Henry Negretti (1818–1879) and Joseph Zambra (1822–1897) formed a partnership in 1850, thereby founding the firm which would eventually be appointed opticians and scientific instrument makers to Her Majesty Queen Victoria, Prince Albert and King Edward VII, the Royal Observatory and the British Admiralty.[1][2] Henry (Enrico Angelo Lodovico) Negretti was born in Como, Italy. Joseph Warren Zambra was born in Saffron Walden, Essex the son of Joseph Cezare Zambra and Phyllis Warren.[3]

When the Crystal Palace was re-erected in Sydenham in 1854, Negretti and Zambra became the official photographers of the Crystal Palace Company, which allowed them to photograph the interior and grounds of the new building.[4] The firm made use of this access to produce a number of stereographs. In 1856 Negretti and Zambra sponsored a photographic expedition to Egypt, Nubia and Ethiopia conducted by Francis Frith. More than 500 stereographs of Frith's voyage were produced by the firm between 1857 and 1860.