An anonymous reader writes "My father-in-law died some time ago. He was a wonderful and masterful craftsman. From his garage "collection", I received a double-handful of older tools, some obvious, some obviously special-purpose. I was able to track one down to the 1946 (patent filed) — 1949 (patent granted) era, as an "advertising" (but useful!) tool. Sort of an early version of the "swiss army knife", but without having to fold things out. I have another one, a Vernier caliper with sub-millimetric accuract (0.001 meters). It has several capabilities: outside; inside; depth; probably walls, possibly height, and I'm not sure what else. It is marked only "Germany" and a name / abbreviation I haven't figured out yet. It's been neglected a bit, but is still accurate. I can only suppose it was used to measure "cupped" manufactured articles in quality control — pistons, cups, brake calipers, or something similar. I intend to continue to use it as a caliper. But, I would like to track down what it was originally used for. Can anyone point me to some sites that might help?"