Planimeter

From my long time friend and early days programming buddy “Z” comes this obscure piece of information: The Planimeter. For those of you that might remember the Sliderule comes this gem. You can see for yourself at these sites.

http://www.leinweb.com/snackbar/planimtr/
http://baen.tamu.edu/users/munster/agen_468_99/planimeter/planimeter.htm
http://abel.math.harvard.edu/~knill/math21a2001/22-green/planimeter/
http://www.mathematik.com/Planimeter/explanation.html