turret clock

A turret clock is a clock designed for installation in a tower or turret, featuring one or more dials that are separate from the clock's internal mechanism. These large, weight-driven machines were among the earliest mechanical clocks, often found in monasteries to signal prayer times.123

The oldest surviving English turret clock dates back to 1386 at Salisbury Cathedral. These early devices typically struck only the hours and lacked hands or a dial. They were regulated by a verge escapement and could have errors of up to half an hour per day. Later advancements, such as the pendulum in the 17th century and improved escapements like the double three-legged gravity escapement, significantly increased accuracy, becoming standard for tower clocks.3