Do you know how to use a slide rule?

My father in law bought a new house and is moving so last weekend my wife and I were helping him pack. In digging through his attic I found an old slide rule. Being and engineer with a taste for history I decided to learn how to use it. Although its pretty tricky at first once you get the hang of it what it can do is simply amazing. Im still working on log's and trig functions but I can whip up mulitplication and division like a mad man on this thing.

Anyone else mess around with a slide rule on a regular basis? Im thinking of taking it into my next meeting where we're working on something and busting it out when someone needs a calculation done. I bet the look on the old engineers faces would be priceless.

Yeah. My parents both being math teachers had slide rules. I wouldn't have gotten through 3rd grade math without one. arty-smiley-048:

Then I learned how to multiply later down the road.

I have my granddads old slide rule (along with leather case & belt loop attachment)

But I have no clue how to use it, it looked very complicated IMO.

Road Guy said:

I have my granddads old slide rule (along with leather case & belt loop attachment)
But I have no clue how to use it, it looked very complicated IMO.

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Thats what I thought the first time I looked at it. For multiplication and division you can ignore most of the scales and its actually pretty easy. I found a website that explains the theory of how a sliderule works and it was extremely interesting.

I got a Versalog 1460 (a Cadillac of slide rules) for x-mas I've had a cheesy plastic slide rule for a decade or so.

I can do simple multiplication and division, roots, powers, trig, etc. I haven't learned how to string long calcs together yet.

I like to keep one around so that when the young whippersnappers around the office start giving me crap about how close I am to taking a dirt nap, I can pull it out calculate just how close I am to taking that dirt nap :whipping: Other than the principals of this firm, I'm the oldest in the office and take a lot of good natured ribbing about my age.

Isn't everyone under 40 just a kid? :dunno:

There was an engineer :whipping: at my old firm that kept his handy all of the time. Everytime the computers would go dow, he would come out of his office and ask if anyone needed to use his slide rule

Numerous times he tried to show me how to use, but being the "best available technology" guy that I am, I totally refused to learn.

I can play the slide whistle!

I can multiply/divide on them, but I just can't figure out the graphing or matrix functions :whipping:

My supervisor gifted his old slide rule to me. It is one of those things that I intend to 'take up' once I have time. :whipping:

JR

I used one in college...calculators were too expensive, and could not do logs, ln, trig or hyperbolic functions at the time...

a professor once said about calculators, a wrong answer to 8 decimal places is still a wrong answer...

no calcs allowed, do everything long hand and leave in radical form....that way he could see if we grasped theory/problem set-up, rather than just crunching numbers...

I wouldn't even know what one looked like.

^^^^^^^It looks just like an abacus, dusty and unused. I must admit, there is a tiny part of me that is mildly interested in knowing how a slide rule works, but not interested enough to put forth the effort.

Some of the engineers I work with think it's crazy that us young engineers have never seen or used a slide rule. I think it would be neat to learn, but I have no idea. I've never been around one.

I have my grandfather's slide rule in it's nice leather case. It is one of the ones that does just about everything. I also have a cheaper plastic one that he used at home which does the basics. I figured out how to use them years ago, but haven't used them in a long time.

-Ray

JoeBoone82 said:

Some of the engineers I work with think it's crazy that us young engineers have never seen or used a slide rule. I think it would be neat to learn, but I have no idea. I've never been around one.

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I want to learn too but never had a chance.

They have virtual ones on the web somewhere.

My grandfather, who graduated in 1936 from Michigan Tech with a mining eng degree, always tried to teach me how to use a slide rule when I was at Tech. In his opinion using a slide rule made you think about your calculations and therefore less likely to make stupid errors. He also said the best part was that it didn't run out of batteries in the middle of an exam. So until the day he died in 1989 he always used a slide rule and never owner a calculator.

Here is a link to some virtual slide rules if you a interestered.

http://www.antiquark.com/sliderule/sim/

FusionWhite said:

Thats what I thought the first time I looked at it. For multiplication and division you can ignore most of the scales and its actually pretty easy. I found a website that explains the theory of how a sliderule works and it was extremely interesting.

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can you share that website. i have two of my dad's from his engineer school days and would like to scare the new guys in the office by breaking it out in front of them. HAHA

Old as Dirt Geo said:

In his opinion using a slide rule made you think about your calculations and therefore less likely to make stupid errors.

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In a real sense he has a valid point. I see A LOT of kids coming out of college today who only know how to punch numbers on a calculator. It makes for a very poor engineer if you don't have an idea as to what the range of values should be as an end result of performing some sort of mathematical operation (e.g. add, subtract, log, trig, etc.). Having an idea of the expected outcome provides the first line of proofing your work - a skill that is VERY MUCH IN NEED these days.

Thanks for the link!! :thumbs:

JR

jregieng said:

In a real sense he has a valid point. I see A LOT of kids coming out of college today who only know how to punch numbers on a calculator. :blush: It makes for a very poor engineer if you don't have an idea as to what the range of values should be as an end result of performing some sort of mathematical operation (e.g. add, subtract, log, trig, etc.). Having an idea of the expected outcome provides the first line of proofing your work - a skill that is VERY MUCH IN NEED these days.
Thanks for the link!! :waitwall:

JR

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Very true... a lot of our new hires here have no concept of the numbers that they are cranking out and can't look at them to think that something may seem out of whack.

-Ray