The Complete Handbook of Clocks

Chapter 1: Understanding Clocks

A clock is a machine that counts a recurring action to divide time into equal, measurable segments. That is the entire principle. Every mechanical watch, every quartz clock, and every atomic time standard relies on three things: a source of power, a way to regulate the flow of that power into discrete beats, and a system to count those beats and display them. Understanding this universal architecture is the most useful single piece of knowledge you can carry into the field, whether you are buying a clock for a waiting room, adding a new model to a collection, or repairing a movement that has stopped for no visible reason.

Consider a simple mechanical clock, like a traditional schoolhouse wall clock. The power source is a mainspring: a coiled strip of hardened steel that is wound tight with a key. As the spring unwinds, it turns a series of gears called a gear train. The gear train does not simply spin freely; its motion is released in small, controlled increments by an escapement. In a typical clock, the escapement is a wheel with specially shaped teeth that lock and then slip against two metal pallets attached to a pendulum. Each swing of the pendulum allows the escapement wheel to advance one tooth, and the gear train, in turn, moves the clock's hands forward one tick. The pendulum is the regulator; its length determines the rate at which it swings, and therefore the rate at which the clock