Thomas PORTHOUSE. Two-day marine chronometer,... Lot 131

Thomas PORTHOUSE. Two-day marine chronometer, identified by its number "6604". Circa 1840. It is protected by a rosewood box with three levels. This model from the famous manufacturer Thomas Porthouse has a power reserve of 56 hours. On the silvered main dial, the hours are in Roman numerals. The minutes in one sub-dial are counted in Arabic numerals and in another sub-dial the hours are recorded up to 56. On the latter, it is marked "wind" at the 24-hour mark, which means that it is advisable to wind it up after 24 hours of walking. It is marked "Thomas Porthouse - Maker to Admiralty - 10 Northampton Square LONDON. The stopwatch is mounted "cardanically" and has its own locking system so that it can be moved (or even transported) without damage. It has its own winding key. The movement is enclosed in a drum, dust cover, made of brass. The high quality rosewood case is on three levels with brass reinforcement corners on all three levels. Small rectangular bone plate engraved with the name of the maker. Inlaid mother-of-pearl medallion below the lock entrance. The key is there. Two hinged brass carrying handles allow the safest possible movement. Box dimensions: 19.5 x 16.8 x 16.8 cm. Sold as is. Note: Thomas Porthouse (1794/1860) gained a considerable reputation as a manufacturer of precision watches and marine chronometers. In 1815 he set up his own business on the High Street in the East End of London. He moved to Northampton Square around 1835. He supplied many marine chronometers to the Royal Navy and the Admiralty. He collaborated with Greenwich to perfect the measurement of time.