The precision required for making clock and watch parts demanded that artisans possess reliable indexes of measurement. In the eighteenth and early nineteenth centuries gauges of the type seen here were used to measure the thickness of arbors, spindles, pinions, clock or watch plates, and other metal parts. Some of those illustrated were undoubtedly made by the Dominys from scrap metal while others were probably bought from local smiths or tool dealers in New York City.

Gauge, Nathaniel Dominy IV (maker), 1760-1812. Iron. 3.7" (L). Museum purchase with funds provided by Henry Belin du Pont, 1957.0026.450

The depth gauge, also known as a "Deepening" or "Pitching" tool, insured a proper fit for the teeth of gear wheels and pinions made by the Dominys.  A combination of toothed wheels, wheels and pinions, or pinions could be suspended between the upper and lower arbors. After the necessary adjustments had been made and the teeth were meshing correctly, a compass, or dividers, could be used to measure the distance between the pivots of whatever combination was on the tool. This measurement could then be transferred to clock or watch plates to mark the place where pivot holes should be drilled.

Depth gauge, Nathaniel Dominy IV (maker or purchaser), 1760-1812. Iron; Steel. 8.1" (L). Museum purchase with funds provided by Henry Belin du Pont, 1957.0026.426

This Dial-Marking Gauge was presumably used in the process of gunsmithing. The Dominys repaired and stocked many guns. It is conceivable, therefore, that this tool may have served as a gauge to set the correct angles for a gunlock in its cocked and strike positions. This one is stamped with the date 1779, when Nathaniel IV made it, and also bears an inscription indicating that it was revised in 1818. That date coincides roughly with Felix Dominy's entrance into the clock shop, and it is logical to assume, therefore, that this tool had something to do with clockmaking. The section of a circle scratched on its surface is marked, however, only from 5 to 35, certainly not enough to enable a dial-marking gauge to function successfully.

Dial marking gauge, Felix Dominy; Nathaniel Dominy IV (maker, 1779), Felix Dominy (reviser, 1818). Satinwood; Iron. 7.2" (L). Marks: "1779" stamped, "revised in 1818" stamped. Museum purchase from Nathaniel M. Dominy, 1957.0084.022