Many of these instruments are still in occasional use in my workshop, where I build model steam engines, whilst others are purely part of my collection. Mostly they date from the first half of the twentieth century. Cheap digital calipers have even virtually made many of them obsolete in model engineering workshops now. The photographs show them in used condition, rust and all, which is how they were when I inherited or obtained them. There are also rules and gauges from other trades that I have collected.