The most practical tool for measuring the circumference of a wheel and transferring the measurement to an iron tire was the traverse wheel, or traveler. A blacksmith or wheelwright noted the number of times a marker—in this case a hole punched through the iron wheel—passed a given point on his traveler. The same number of revolutions were then marked on a piece of iron-tire stock to obtain the exact length needed. Wheelwrighting was one of many occupations pursued by Nathaniel Dominy V. This tool would not have been useful, however, until after the clock shop and forge were built in 1797. Perhaps it is an early attempt at smithing on the part of Nathaniel IV; it is certainly a crude example of toolmaking.
Traveler, Nathaniel Dominy IV or V (maker), 1800-1840. Birch; Iron. 15.2" (L), 9.56" (D). Museum purchase with funds provided by Henry Belin du Pont, 1957.0026.395