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  • Author Author: dougw
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Just How Cool Is A Hemmi Slide Rule

dougw

I made an unexpected discovery the other day while purging some old dead storage. I came across a slide rule and a super 8 movie camera. At this point, these items are mostly just curiosities, but I thought I would see if I could remember how to use a slide rule and blog about it in case members would find it interesting.

If you went through engineering after 1972, you probably never needed a slide rule because calculators took over  after that.

A decent slide rule jockey could go much faster than a calculator, but that didn't stop us from all wanting a calculator. Using a slide rule requires using quite a bit of brain power to plan operations and keep track of decimal points, and making a mistake in reading the result was very common.

My slide rule skills are pretty rusty and I never got really good at it since calculators became available in my second year of university.

This fairly high end Hemmi Versalog slide rule is made of bamboo with a celluloid surface. It still works perfectly after 50 years, with a very smooth action.

How many of you remember carrying around a little booklet of trig tables, which provided more significant digits than a slide rule could?

https://youtu.be/Q0W2GLUhwWE

It was interesting to dredge up some old memories about my university days and try to recall how to operate a slide rule.

If you have any technology memories from before PCs, feel free to comment below.

  • Thank you for your year in review. I missed this post the first time around. I always enjoy nostaliga. Reading the post caused a a dormant memory synaps to fire. I went into storage to locate my Mathematical Tables. This was the only calculator permitted for matrculation exams in high school 1978.

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    I'm not sure of the quality of the image but below the table of contents is the published dates. First published in 1927!

    In our province students had to purchase text books from the school. If you were lucky, parents found students from previous years and purchased text books from them at a large discount. Some brown meat packing paper to cover the text book jacket and you were ready for the next year. The writing on the cover of the tables is from the previous owner. The scribbles on some of the pages look to be mine.

    My apologies for the small script. I failed to find any option in this editor to enlarge it. I thought I could do that. Looks like it another enhancement not supported across all pages.

  • in reply to Andrew J

    I had an Otis King cylindrical slide rule in the late 1960s https://en.wikipedia.org/wiki/Otis_King

     

    It had a nominal scale length of 66" - 10 times the accuracy of a 6" linear slide rule. In reality, some of the markings were a bit inaccurate!

     

    Most friends and colleagues were intrigued by it.

     

    Neil

  • I Bought a slide rule when I was at school just because I thought it was cool - what a nerd!  You’re comment on working fast on a slide rule reminds me of the Harwell Dekatron

     

    This is a slooooooow computer: so slow, an experienced adding machine operator could keep up with it.  At least until boredom crept in along with mistakes.

     

    Some  of the coolest slide rules are the cylindrical ones, such as the Fuller and Curta rules.

  • I had several slide rules over the years but lost my "good" one at some point.  The Post is an inexpensive one from high school and my first one.  The pocket slide rule belonged to my father.  The Post is plastic, the K&E bamboo, and the pocket aluminum.  They are all in good working order.

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    I was in the military for several years where I didn't use slide rules and got out of practice.  When I returned to school calculators had taken over and after the first test where I was the only one using a slide rule and definitely wasn't faster (or more accurate) than the other students, I went out and bought my first calculator.

  • I have fond memories of those old college days.  I also had a Hemmi and a Lafayette and a couple of Picketts (aluminum construction).  All of them still working well today.  I used to carry the pocket one to use when I was working in the lab.

     

    Not many of us had calculators in those days, so we weren't required to have a lot of precision in our exams.  The engineering slide rule was great because it allowed you to read the frequency, wavelength and impedance numbers directly off the scale without having to do the calculations.  Used to be a lot faster in exams than the guys with calculators image.

     

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