I loves me some paper calculators, yessir. My first one I remember was a simple slider that did multiplication and came out of a box of cereal in 1970-something. The idea of a computer constructed out of paper fascinated me immediately, and I wore that cereal box calculator to shreds as a kid. Later in life, I had much occasion to use a Proportional Scale, which is a calculator for proportionally scaling images into enlargements or reduction for darkroom work.
I’m still fascinated by them, and today I found some really nice examples in great shape for a couple bucks.
(these are actually very high-resolution scans. to see them full size, save them to your computer or right-click and select “View Image”)
I present to you:
The Lightning Calculator Type A
Published by The American Radio Relay League, Inc. (1932)
The Lightning Calculator Type B