# Slide Rules Rule!

Updated on January 3, 2010

## Slipstick spirit lives on!

Are you an engineer? Okay, cool, so you have a slide rule, right? Wait, what? No slide rule? How can you call yourself an engineer then? A scientist? I mean, don't you LOVE logarithms? And trigonometric functions? And order of magnitude has always been easy to keep track of in your head, right? No slipstick?!

Alright, I'll help you out here. This lens will give you another notch on your geek belt. Yeah... I see you smiling now!

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## A Brief History of the Slide Rule

### Excerpt from Wikipedia

The slide rule (often nicknamed a "slipstick") was developed by William Oughtred and others (see history, below); it is a mechanical analog computer, consisting of at least two finely divided scales (rules), most often a fixed outer pair and a movable inner one, with a sliding window called the cursor. The slide rule is used primarily for multiplication and division, and also for "scientific" functions such as roots, logarithms and trigonometry, but does not generally perform addition or subtraction. The Binary Slide Rule manufactured by Gilson in 1931 performed an addition and subtraction function limited to fractions.

Before the advent of the pocket calculator, it was the most commonly used calculation tool in science and engineering. The use of slide rules continued to grow through the 1950s and 1960s even as digital computing devices were being gradually introduced; but around 1974 the electronic scientific calculator made it largely obsolete and most suppliers exited the business.

Read the rest of the article.

## Slide Rule History

Slide Rules: A Journey Through Three Centuries

Originally published in German in 1977 as the first major book on the history of the slide rule since Florian Cajori's A History of the Logarithmic Slide Rule, this newly revised and translated edition of Slide Rules, A Journey Through Three Centuries, offers readers a fresh, more Continental perspective on this most fascinating of calculating instruments.

## Learn to Use the Slide Rule

The basic math of the slide rule lies in the logarithmic scales marked on the device. Multiplication and division of large numbers can be easily done by aligning the appropriate marks. In essence, moving the slider allows you to add the distances on the slide rule, and with logarithm rules in mind, log(A)+log(B)=log(AxB). Confused? Try it out for yourself. Oh, riiight, you don't have a slide rule yet. Use a virtual one, then.

## Using the Slide Rule

Slide Rule, How to Use It (Everyday Handbooks Series)

simple, practical guide with complete instructions.

## Linear Slide Rules

Okay, you're ready to get your own slide rule now. Take a peek. Get your own pocket-sized slipstick to truly become old-school engineer! Ditch your calculator. They use electricity.

## What is 2 x 2?

The engineer whips out his slide rule, shuffles it back and forth, and finally announces "3.99".

## Circular Slide Rules

If you're always doing calculations that make you run out of room, you need a wrap-around circular slide rule. Oftentimes, you'll get increased accuracy on the outer scales, too. They come with one or two movable arms.

## GIANT Slide Rules

Do you believe bigger is better? Check out some of these large demonstration slide rules. Great for classrooms and living rooms. Or bedrooms, too.

## Slide Rule Watches

You think engineers are the only ones who used slide rules? Well, you know what, pilots use slide rules, too. And they are so cool that they still use them today! It's a fast way to calculate speed, distance, fuel use, etc. The E6B style watches go great with aviator glasses.

The Slide Rule, Simplified, Explained, and Illustrated for the Mechanical Trades

This book, first published in 1881, was written about the use of the first standard slide rule made in the United States: a Mannheim-type slide rule made by Stephens Co., a major rule manufacturer. As a source book, it should be of great interest and value to tool collectors, slide rule enthusiasts, and woodworkers.

So, you're ready to take the leap into collecting? Check out these resources online, and you'll find that you're joining a very vibrant community.

## Have you got your slide rule yet?

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• Carol Fisher

7 years ago from Warminster, Wiltshire, UK

I've heard of slide rules and I knew they were used for calculating but this is the first time I've seen a picture of one and read an explanation of how they were used. Blessed.

• LabKittyDesign

8 years ago

Sorry, anything less than an HP15c and it ain't worth the effort. Hard to imagine they built atom bombs with these things (and a lot of Marchant calculators). Great lens.

• anonymous

8 years ago

Well done interesting topic. There is a teacher in Vancouver, B.C. who insists students use slide rules. It appears he has bought up just about every slide rule in existence. He believes that the information sinks into their brains faster, and they are challenged more if they use slide rules.

• anonymous

8 years ago

Well done interesting topic. There is a teacher in Vancouver, B.C. who insists students use slide rules. It appears he has bought up just about every slide rule in existence. He believes that the information sinks into their brains faster, and they are challenged more if they use slide rules.

• Jeanette

9 years ago from Australia

I know my dad has a slide rule but I've never actually used one. Great lens.

• anonymous

10 years ago

Terrific lens! I didn't realize that there were so many people collecting these wonderful old tools! 5 stars!

• ElizabethJeanAl

10 years ago

Mention a slide rule to the younger generation and they give you a blank look. I have one in my classroom. I call it my manual calculator. The kids love it...as long as they don't have to actually use it.

Great lens

Lizzy

• Ruth Coffee

10 years ago from Zionsville, Indiana

I still have a slide rule although I dont' really recall using it; we had large, clunky, and somewhat expensive calculators. My husband is an engineer and he likes doing everything the hard way so he can appreciate this page!

• The Homeopath

10 years ago

Oh dear. I am old.

• Roxy Calamari

10 years ago

Great lens! I had no idea that slide rules were collectibles. 5 stars!

• Tony Payne

10 years ago from Southampton, UK

I remember using them at school. Never did like it much. Thankfully we now have calculators. I also remember using compometers too.

• MacPharlain

10 years ago

My high school math teacher had one of the big demo slide rules hanging up in the classroom. He'd take it down and use it occasionally.

• religions7

10 years ago

My dad is a mathematician / IT specialist. He has one in his desk and used to show me how it works. Never converted me though :) calculators are so much easier.

• KimGiancaterino

10 years ago

My dad is an engineer, so slide rules were basic equipment at our house. I still have a couple in my desk drawer!

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