What Makes a Sea Chronometer So Precise?

Marine chronometers are key-wound, spring-driven timekeepers that are more precise than most others mainly because of several special features:      

MAINSPRING ARRANGEMENT – Combines the spring with a fusee to equalize the force of the spring as it unwinds.

SPRING DETENT ESCAPEMENT – Transfers power from the spring to keep the balance swinging regularly, while interfering with it as little as possible.

BALANCE WHEEL – Regulates the pace of the chronometer with a special combination of two metals that expand and contract at different rates to compensate for temperature changes.

PROTECTIVE BOX WITH GIMBAL – Holds the chronometer level with the horizon to prevent position changes that can alter its ability to keep precise time.

Caption:
Marine chronometers are key-wound, spring-driven timekeepers that are more precise than most others mainly because of several special features.
Type: Illustration
Image Date: 2012
Credit: National Air and Space Museum, Smithsonian Institution
Origin: National Air and Space Museum, Smithsonian Institution
Creator: Bruce Morser
Navigation Methods
 
Marine chronometers are key-wound, spring-driven timekeepers that are more precise than most others mainly because of several special features.