Museum-Quality WWII Hamilton Model 21 Two-Day Marine Chronometer (1941) Ships Chronometer

Museum-Quality WWII Hamilton Model 21 Two-Day Marine Chronometer (1941) Ships Chronometer

An exceptional, historically significant piece of World War II American horological history. This genuine Hamilton Model 21 two-day marine chronometer is in absolute working order, housed in its original brass-bound campaign rosewood box, and has been fully serviced.

Key Product Highlights
• Historic 1941 Production: Features a beautiful 4-inch silvered dial proudly signed “Hamilton Lancaster, PA., U.S.A.” alongside the military registration serial number N 7832 and the contract date of 1941.
• Prestigious Model 21 Movement: Driven by Hamilton’s legendary 14-jewel chain fusee movement featuring an Earnshaw-type spring detent escapement, maintaining power, and a revolutionary Elinvar helical balance spring—widely regarded as the most accurate mass-produced mechanical timekeeper ever built.
• Fully Serviced & Working: This serving chronometer has been meticulously disassembled, cleaned, oiled, and timed. It runs strongly, keeping exceptional, chronometer-grade time.
• Two-Day Power Reserve: Equipped with a 48-hour “Up/Down” state-of-wind indicator dial below the 12 o’clock position to track remaining mainspring power.
• Campaign Rosewood Box & Gimbals: Safely suspended in its original weighted brass gimbal ring system inside a premium three-tier brass-bound campaign rosewood/mahogany box with a glazed viewing port and side drop carrying handles.

Detailed Specifications
• Manufacturer: Hamilton Watch Company (Lancaster, Pennsylvania, USA)
• Model / Caliber: Model 21 (14 Jewels, Chain Fusee)
• Serial Number: N 7832 (Matching dial and movement plates)
• Date of Contract: 1941
• Power Reserve: 2-Day (48 Hours manual key wind)
• Height: 17.5 cm
• Width: 19.0 cm (Approx. 7.5 inches standard square casing)

Condition Report
This maritime instrument is in excellent aesthetic and mechanical condition. The silvered dial is remarkably clean, showing crisp black Arabic numerals and clear engravings with virtually no spotting or oxidation. The original blued steel spade hands are immaculate. The heavy brass gimbal mount moves smoothly and locks securely. The protective rosewood campaign box displays a beautiful historic grain pattern and robust joinery, showing only minor superficial storage wear consistent with genuine naval service history.

Specialized Shipping Notice
Due to the highly sensitive nature of spring detent chronometer escapements, this item requires specialist handling. The balance wheel must be safely wedged with a soft cork block prior to transport to prevent pivot damage. The chronometer will be shipped locked, wrapped in heavy multi-layer bubble cushioning, double-boxed, and dispatched via a fully tracked, signed-for, and insured premium courier service.