Why does a mechanical watch go “tick-tock”?
The ticking is produced by the escapement, which plays a key role in the movement’s measurement of time. “Tick”: a tooth of the escape wheel locks against one of the pallets of the lever. Then, released by the sweep of the oscillator, the pallet fork lets the wheel “escape”, until it locks against the second pallet: “tock”.
The pallet fork continues its infinite pendular beat against the oblique teeth of the escape wheel precisely 28,800 times every hour – 14,400 “ticks” and 14,400 “tocks”. That's 250 million times a year.
