Steam watch

The heart of any watch is a regulator that runs at a constant rate. In a quartz watch, this is an oscillator circuit that runs a 32768Hz. In a real (ie, mechanical) watch, it is a balance wheel and hairspring with a constant resonant frequency of a few Hertz.

Steam engines, however, can also be made to run at constant speed, my means of a Watt centrifugal governor. The governor consists of two heavy balls on hinged arms, affixed to the output shaft of the steam engine. As the shaft speed rises, the balls are thrown outward by centripugal force, and this in turn closes a valve, reducing the steam supply and slowing the engine. If the shaft slows, the reverse occurs.

With this in mind, it is astonishing that nobody has produced a steam wristwatch until now. The governor will have to rely on springs (rather than gravity) for the centripugal force to act against, but will otherwise remain pretty much the same. Furnishing a miniature wrist- mounted firebox, boiler and piston arrangement are problems too trivial to dwell upon. A simple asbestos pad will ensure the continued comfort of the wearer.