Porthouse & French, London. No. 7731

A good 2-day marine chronometer with a best quality 'fancy' box of the period. Circa 1862.

Case

Superb 3-piece brass-strung rosewood box with mother-of-pearl plaques, possibly cased for exhibition at the London International Exhibition of 1862; contained within what is probably its original mahogany travel or 'guard' box.

Dial

Silvered dial signed Porthouse & French Makers to the Admiralty 16 Northampton Sq. London. 7731. Subsidiary seconds dial with state-of-wind indication at XII, gold hands.

Movement

Fullplate fusee movement with diamond cap jewels on balance, the brass bowl numbered as the dial. Earnshaw spring-detent escapement, the detent of standard footed form with gold passing-spring. Compensation balance with 9-turn blued-steel helical balance spring.

Box 18 cm square.

Mrs Thomas Porthouse (widow) in partnership with William French, watch and chronometer maker, working from 16 Northampton Square, Goswell Road, the heart of London's premier watch and chronometer making district. The firm is known to have exhibited "specimens of marine chronometers and watches for home and foreign markets" at the 1862 London exhibition, as part of Class XV 'Horological Instruments,' an account of which is reprinted as Appendix D in the book Thomas Cole & Victorian Clockmaking by J B Hawkins. See also the National Maritime Museum chronometer catalogue by J Betts, page 299.

Previously maintained at the US Branch Hydrographic Office, Savannah, Georgia in 1919, possibly having been requisitioned for American use during the 1st World War.