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"This is done in the mechanism of the watch, of which a, is the barrel containing the power in the form of a convoluted spring, and b the fusee which acts as a varying lever, and through which motion is conveyed to the hands of the watch." -Comstock 1850

Barrel and Fusee

"This is done in the mechanism of the watch, of which a, is the barrel containing the power in the form…

"A key is used to turn the cone, B. By doing so it wraps the chain around the cone and tightly coils the spring inside the barrel, A. The spring draws the chain off of the cone turning the barrel." —Quackenbos 1859

The Fusee

"A key is used to turn the cone, B. By doing so it wraps the chain around the cone and tightly coils…