Recently I bought a dial caliper at the flea market. It's a Mitutoyo, and the dial is graduated in .001" increments, but it will make a complete revolution once every 0.2", instead of the usual 0.1". What is the purpose of a dial graduated this way (Zero is at both 12 and 6 o'clock)? It's a bit of a test of my vision to read it, but it was worth the 5 bucks the kid wanted.
Also, thanks to Michael Koblic for the link to Long Island Indicators. I replaced the almost opaque crystal, and now I can fail to see the small graduations a little easier. I ordered on Friday, they (supposedly) shipped it US Mail on Saturday, and it was waiting in my PO box Monday afternoon!