Historically I believe they were just "computers" but that is just about impossible to search for these days. "Slide charts" is what I have the most luck with.

Historically I believe they were just "computers" but that is just about impossible to search for these days. "Slide charts" is what I have the most luck with. I've inadvertently picked up a couple (usually tucked into old engineering books I've purchased)so looked into them a while ago. This page has a great collection of them: http://www.mathsinstruments.me.uk/page66.html http://www.mathsinstruments.me.uk/page66.html That search term also pulls up a ton on ebay.