The first true circular dividing engine was probably constructed by an English clockmaker before 1750. John Smeaton, the first self-proclaimed "civil engineer" reported this invention to the Royal Society 1785 in his Observations on the Graduation of Astronomical Instruments. It was based on a gear cutting machine for clockworks and used a toothed index plate and a gear to move the mechanism.

This is one of the earlier hand-operated tabletop American gear cutting engines, probably made in Connecticut around 1780. It has a 7” wooden rectangular pedestal with iron base and drive pulley, brass dividing wheel and fittings and ebony handles on base. The wheel blank is mounted firmly on the central spindle, integral with the index plate. Each tooth space is formed by bringing the rotating cutter through the wheel-blank, after which the index plate is moved the next location.

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1802.68 H 14”