Slide Rules

Relics of the Past

Have you ever used a slide rule? Have you ever HAD a slide rule? Have you ever SEEN a slide rule? Have you ever HEARD of a slide rule? Do you even know what a slide rule is?

Your age probably determines whether or not you answer “Yes” to one or more of these questions.

When I was in high school, many of us learned how to use a slide rule (known colloquially as a “slipstick”) whenever we had to make mathematical calculations. You see, we were deprived. There were no such things as calculators, not to mention computers.

Oh, there were adding machines, but those couldn’t do much more than add or subtract. It wasn’t until I went to college that pocket calculators came about, but those cost around $25 apiece and couldn’t do much more than add and subtract, multiply and divide.

Then, sometime around the mid-70s, somebody invented the scientific calculator that could do all kinds of mathematical functions and slide rules went the way of automobile running boards, manual typewriters, and ice boxes. Down with finger power, up with batteries. Analog was on its way out, digital was on its way in.

I had a pretty good slide rule. Most were made of mahogany or boxwood and some had steel slides. Some of the best were made of bamboo. Some were aluminum. Mine was an economy model made of plastic.

We all carried one around to use in physics class and they were allowed during exams. When pocket calculators became prevalent, the calculators were banned during tests, so the slide rules prevailed.

Slide rules were awesome. You could do multiplication and division, roots and powers, trigonometry, logarithms and exponentials, and … basic addition and subtraction if you really wanted to. Although most were linear like regular rulers, they did make circular slide rules. Come to think of it, slide rules pretty much defined nerdism, not unlike plastic pocket protectors.

That picture at the top of this blog entry? It’s a bunch of vintage slide rules on sale at the most recent collector’s show I attended. They were priced from $50 to $500, depending on size and manufacturer. I was tempted to bring mine down (yes, I still have it) and ask the guy in the booth how much he’d pay for mine.

Nah. I’m keeping mine. Who knows? Someday electricity may fail for good, batteries will run out for good, and people will have to pay me to do their calculations for them.