Its easier for people to have a tailor tape for measuring rather that a caliper, so I think 13 might be the girth. 13÷π = ~4.13cm diameter (excluding major irregularities)
Also the calipers were cold and caused unfavourable shrinkage.
Its easier for people to have a tailor tape for measuring rather that a caliper, so I think 13 might be the girth.
13÷π = ~4.13cm diameter (excluding major irregularities)
Also the calipers were cold and caused unfavourable shrinkage.