Hamilton Model 21 Marine Chronometer with Rare Original Inner and Outer Box
Since its invention in 1761 by John Harrison of England, the marine chronometer has been used for navigational purposes. Its precision and reliability for accuracy to within seconds is truly remarkable. As a result, many marine vessels stayed safe and on course for hundreds of years.
Among the finest navigational timekeepers ever produced in America, the Hamilton Model 21 Marine Chronometer represents the height of precision horology developed for maritime service during the Second World War. Manufactured in Lancaster, Pennsylvania, these chronometers were built to exacting standards for the U.S. Navy, where accurate timekeeping was essential for determining longitude and safely navigating the world’s oceans.
This exceptional example retains its original engraved Arabic-numeral dial with subsidiary seconds and a 56-hour power-reserve indicator. At its heart is Hamilton’s 14-jewel chain-driven fusee movement fitted with a detent escapement and helical hairspring, an arrangement specifically engineered to deliver extraordinary accuracy under demanding conditions. Suspended within a brass gimbal system, the movement remains level despite the motion of a vessel, ensuring reliable performance at sea.
The chronometer is housed within its original fitted mahogany inner box with brass hardware and remains accompanied by its original outer mahogany carrying case with leather retaining strap. The survival of both cases, together with the remarkable originality and preservation of the chronometer itself, makes this an especially desirable example of one of America’s most important precision instruments.
Circa 1941