Longitude by chronometer

Longitude by chronometer refers to a method of determining a ship's longitude at sea using a marine chronometer. This innovative technique was developed in the 18th century, primarily credited to the work of British clockmaker John Harrison. To calculate longitude using a chronometer, the following steps are typically followed: 1. **Timekeeping**: A marine chronometer is a highly accurate timepiece that is set to Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC).