What is it? – The venerable tracing wheel.  The first one I ever saw was as a youngster looking through my grandmother’s sewing basket.  I thought it was there by mistake.  It was obviously a toy.  What could a stick and a wheel possibly have to do with sewing?  Fast forward a few decades and it is all clear to me now.  Not that I use it, I just have an appreciation of its use as a sewing tool.  Almost everything we construct when we sew uses a pattern at…