Brass and Steel Dial-indexing Engine

Description:

Brass and Steel Dial-indexing Engine, France, late 18th century, with pivoting brass and steel arms and an adjustable thumbscrew-tightened pin, and rings of holes for the accurate and regular division of watch dials, (dial supporting ring a replacement),ht. 3, index dia. 6 in.

Note: Crom #2 discusses this tool in detail on pp. 424-425, and in figure 857. Notably, it is explained which purpose each division ring serves. The appearance of division rings in powers of ten indicates a date and origin in France around 1792-1795, during the French Revolution, when the law there required ten-hour dials (and 100-minute hours) due to the use of the metric system.
Estimate $250-450

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