The Long History of Watch Making

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For a number of years before the wrist watch became a common sight, the standard for personal timekeeping was the pocket watch. Pocket watches are said to have originated in Germany towards around the end of the fifteenth century. The design of early pocket watches was patterned after the clock designs of the day.

What made pocket watches different from clocks was the mechanism used to drive the watch, which used a balance wheel, hairspring and a mainspring. The clocks of the time relied on a combination of counter weights and a swinging pendulum.

The basic design of a wrist watch has not changed over the years, and still uses two basic components. Wrist watches all have some type of metal case with the works of the watch inside. The case was usually made up of three pieces, the bezel, the back and the crystal. Different metals were used for the cases of early pocket watch cases including silver and gold. Over the years, less expensive metals, including pot metal and stainless steel were used for the case. The design of early watches made them susceptible to moisture and dirt that required regular cleaning.

The gears and wheels that made up the inner works of early watches were sandwiched between two metal plates. The pillar plate rests closest to the dial. The upper plate was often made from two pieces though better quality watches were made from a single piece upper plate. Both the upper plate and the pillar plate were precisely machined and drilled. The location of the holes had to be precise since the assembly of depended on it. The four wheels that were part of the inners works are called the first wheel, the second wheel the third wheel and the barrel wheel. The barrel wheel acted as an attachment point for the mainspring. In order to reduce wear on moving parts, certain gemstones were used as bushings and bearings.

The motion needed to power the watch was supplied by the uncoiling of the main spring. The rate at which the spring uncoiled was controlled by the escapement which was is kept moving by the combined action of the mainspring and the hairspring. The result was oscillating movement that drove a sixty gear tooth wheel, engaging the escapement wheel and transmitting motion to the minute hand. It also meshes into the pinion of the center wheel which transmits motion to the hour hand. The movement was controlled by a lever which that was connected to the hairspring. Moving the lever to the left or to the right increased or reduced the tension placed on the hairspring.

Plate stock of brass or steel was used to manufacture the plates for the inner works. Often, a master plate would be made be machined and used to make exact copies. Early machining techniques might have included the use of a pantograph machine which would produce a duplicate of the master plate. The plates would deburred and polished after machining. Gemstones like diamonds, garnets, sapphires and rubies garnet, rubies, sapphires and diamond would be cut into small disks and set in gold. The assembly of the watch works was very intricate and required screws that were of precise dimensions. The small gears needed for the movement were stamped out of brass, using precision made metal dies. Springs were hand formed from very fine spring wire.

Watch dial faces were stamped out of a base metal, coated with enamel and the markings would be applied using a stencil. The dial face would then be fired in a kiln. Some watch makers would alternately subject the finished watches to cold hot temperatures in order to test the watches operation.
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