[OT] Funny ruler by Jinx .

Can anyone tell me what this ruler is for http://home.clear.net.nz/pages/joecolquitt/ruler.gif I picked it up in a stationer's because it's stiff aluminium and has inches and cm. Oh, and it was dirt cheap and not plastic The only side that is truly 12 inches is the 1/16th inches, which is also the longest Others are 1:100 (cm) 0-30 1:200 0-60 1:250 0-75 1:300 0-90 1:400 0-120 I'm sure these scales have some absolutely wonderful uses. If I knew what they were (nothing at all on the wrapper). Is this a draughtsman's or architect's scaling ruler or something like that ? How can I use it with a PIC ? (poking or threatening misbehaving circuits maybe) =============================================== If you aren't part of the solution, you're part of the precipitate