balance

Horology is the science of measuring time and the art of making time-indicating instruments. The first portable timepieces, known as watches, emerged around 1500. These early watches, often with a single hand for hours, were driven by a mainspring that stored energy.12

A key component in mechanical watches is the balance, which oscillates and controls the release of energy from the mainspring through an escapement, regulating the watch's timing. Early watches faced challenges with the mainspring's varying torque, which affected accuracy. Innovations like the fusee and later the going barrel helped to provide a more constant force.2

The development of the balance spring, particularly the spiral form, was crucial for improving the regularity of the balance's oscillations. Modern watches often use a lever escapement and jeweled bearings to minimize friction and enhance precision. Some balances are designed as compensation balances, using two metals with different expansion rates to counteract temperature-induced changes in the hairspring, thus maintaining accuracy.23