Two generations ago a standard uniform identified engineers: white shirt, narrow tie, pocket protector and slide rule. The shirt and tie evolved into a T-shirt sporting some software advertisement. The pocket protector has been replaced by a cell phone holster. And the slide rule has become an electronic calculator.
Take another look at that slide rule. Pull it out of the drawer you stashed it in 30 years ago or make one of your own [see box on next page]. You’ll see why it was once so valuable.
Before the 1970s the slide rule, or slipstick, was as common as the typewriter or the mimeograph machine. A few seconds of fiddling let scientists and engineers multiply, divide and find square and cube roots. With a bit more effort, techies could also compute ratios, inverses, sines, cosines and tangents.
Inscribed with a dozen or more function scales, the slide rule symbolized the mysteries of arcane science. Truth is, though, two scales did most of the work, as many technical jobs boiled down to multiplication and division. A pianist might play most of the ivories on the keyboard, but rarely did any engineer use all the scales on his (almost never her) slide rule.