Three adjustments are usually employed for this purpose, viz: postions, isochronism and compensation. The fusee is a spiral grooved cone, used to equalize the power of the mainspring.
It is mostly found in 19th century and older watches, although some, if not the most accurate, mechanical Chronometers ever made employed a fusee movement including the famous Model 21 Hamilton ship's chronometer made in the 1940's Lever Set describes a watch that uses a lever to free the setting mechanism. After removing the bezel, and pulling the lever, the hands will swing free when the crown is turned.
The Ball Watch Company did not manufacture watches directly, but the company helped develop the specifications for watches used in railroad service.
Webb Ball established strict guidelines for the manufacturing of sturdy, reliable precision timepieces, including resistance to magnetism, reliability of time keeping in 5 positions, isochronism, power reserve, accompanied with record keeping of the reliability of the watch on each regular inspection.
I collect precision clocks, clocks that are very accurate timekeepers, and marine chronometers; things like that.
I specialize in a few different specific types of pocket watches, but my principal interest is in the Waltham Watch Company, and even more specifically in the American Watch Co. When the American watch industry first began, the first successful company was called the American Watch Co., and it was founded out of the Boston Watch Company, which had failed in 1859. was formed, and it’s generally considered to be the first successful company.
I'm including a model '88 stem and crown to complete the package. There is an extra gold disk behind it adding thickness to allow a diamond to be mounted.I have created a crude animation to show you how the lever moves.a Micometric Regulator regulates the speed plus or minus of the watch in very minute adjustments.Measuring the dial is usually a fair approximation of the lower plate measurement.Tom Mc Intyre talks about antique pocket watches, discussing key manufacturers, the mechanics behind the watches, the varying types, and the collecting hobby in general.Based in Massachusetts, Tom can be reached via his website, American Watch Company Web, which is a member of our Hall of Fame.