The Wheelwrights traveler, as it is called, measured around the edge of a cart or carriage wheel so the proper length of iron could be fitted on the outside of the wheel. In the days before motor cars, this tool was used to help fit metal rims around horse-drawn carriage wheels, it is a Wheelwright’s tool for measuring the circumference of carriage wheels before fitting the metal rim.
You run the traveler around the edge of the bare wheel and count the number revolutions, from that you can work out how many inches the circumference is. You then run the traveler along a flat strip of iron to just short of the circumference of the wheel. The flat piece of iron is bent into a circle and the ends are welded together to form a ring slightly smaller than the wheel. The iron rim is then heated to over 600 degrees which makes it expand to slightly bigger than the wheel. Immediately the rim is knocked onto the wheel and cooled down with water, the rim contracts as it cools compressing the wheel. Using this method to fit a rim ensures that it is unlikely to ever come off.
You may have seen a wheelwrights traveler on a tool stall at an antiques fair or flea market because there are still plenty of them around albeit in slightly different styles. This one was shown to me by Nick White from The Tools and Trades History Society who were holding an exhibition in Blackwood some time ago. This traveler is approximately 8 inches (20 cm) in diameter and 13 inches (33 cm) overall length. The wheel is made of cast iron and shows a measurement of 1 to 24 inches around the circumference.
Before WW1 nearly every village in Britain had its own wheelwright, They were skilled carpenters as well because they had to know how to choose wood for the spokes, shafts, and felloes, feloe is the name given to the pieces that make up the rim. It’s said that there were more than 20,000 wheelwrights at the turn of the twentieth century, Now there are only between 40 or 60 tradesmen left in the whole of Britain who would use one of these, and that number is falling all the time.