There was a time when electronic calculators did not yet exist. This did not stop us from doing complicated things, like going to the moon, figuring out the double helix, or designing the Boeing 747. In those days, when we needed to compute things, we used slide rules which are marvelous and beautiful instruments!

There are many pages about slide rules on the web, and you can still buy brand new slide rules (40 years old but never used, and still in their factory supplied box) in various places. The purpose of this particular and quite idiosyncratic slide rule page is to describe common scales used on slide rules, and the kind of mathematical expressions that could be evaluated with those scales.