Henry Delolme. A rare and unusual 18K gold keywound openface pocket chronometer watch with chain fusée, date and one minute tourbillon

The distinctive shape of the movement's plate and the tourbillon carriage with three curved arms are very similar to the one described and illustrated in Reinhard Meis' Das Tourbillon, p. 122, Z77 & 78.
Henry Delolme, located at 48 Rathbone Place, Oxford Street, London, was active in the mid-19th century as manufacturer, importer and designer of watches and chronometers. At the 1851 Great Exhibition he presented seven gold watches, and two marine chronometers, with isochronous pendulum springs, specimen of the movements, as made in Lancashire to the exhibitor's calibre, two specimens of watch movements, to the exhibitor's calibre. He furthermore exhibited a "Stethometer, to measure the comparative mobility of the chest in cases of disease of the lungs".