Slide Rules

Either memory fails me (again!) or my research capabilities have dwindled. Surely, I posted about slide rules some years ago, no? If so, I can't find it. I find My first college campus - MSM; but it mentions, not, a slide rule. I find all sorts of STEM postings; but, they mention, not, a slide rule. This posting was prompted by, and expands upon, comments to the previous posting Proof.

Family history of slide rules

The photo, below, shows my own repository of slide rules. Slide rules are kept in a plant pot atop a corner shelf in our front room (AKA "The Piano Room"). Until this morning (2/11/2018), the slide rules comprised Hunky Husband's late father's slide rule (Pop was a chemist who worked as a chemical engineer until deciding to return to school to complete a degree in pharmacy - which he financed by teaching chemistry), and my own 12" and 6" slide rules. [Thirty years ago I had given away another, less expensive but more modern, 12" slide rule to my nephew's wife or there would have been one more. In addition, HH could not tell me where to find his 6" slide rule. And...I returned "my" Curta Calculator to its original owner, Elder Brother.] Since gathering items for the photo, I've added my E6B and, by his permission, HH's slide rule to the plant pot.

The two photos, below, take a closer look at all of those slide rules. The first two photos show the slide rules nestled within their cases - obverse and reverse sides.

Left-to-right in either photo: Pop's 12" bamboo Keuffel & Esser (K+E) from the late 1930s; HH's 12" bamboo K+E from the mid 1950s; my 12" aluminum Dual-Base Log Log (Model 3-T) Pickett & Eckel (P&E) from 1955; my 6" plastic (Model CSG-1P) Jeppesen Slide Graphic Computer from the early 1960s; my 6" aluminum Log Log (Model N300-ES) P&E from the early 1970s

Not Pictured, because we own none, are any Post or Dietzgen slide rules although they were popular brands in the 1950s

Note the hanging hardware on the 1950s-era slide rule cases. Note, too, that HH has the clip-on belt attachment loop clipped to the slide rule case hardware. Since I carried my slide rule instead of hanging it from a belt, I had no such additional hardware. I suspect that the reason the leather of my slide rule case is darker than is HH's would be the oils picked up by the additional handling it experienced.

The next two photos show the slide rules themselves, obverse and reverse sides.

In case of power failure, we are well equipped to carry on with any required calculations!

Stu's contributions

Since most of his school and career years were spent in the UK and Europe, the equipment Stu used for calculations had slight variations from that with which I was familiar. With his kind permission, I'll include Stu's photo of one of his slide rules, a VEB Mantissa DDR school slide rule, below. Via email Stu clarified, as follows:

"It is an East German school slide rule which means there are NO scales on the other side, it is blank.

"All my Brit slide rules had scales on both sides."

Without Stu's permission, the below photo was stolen from Pooley's Flight Computers. It shows a European "E6B" that is probably similar to what he has since his is the same brand, at least.

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I had thought that this posting was complete - ready to publish. I was wrong. Stu sent me a couple more emails, one of which had the following images attached showing more views of the Aviat. Thank you, Stu. As usual, a larger version of each image may be accessed by clicking on it.

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Late Addition (2/12/2018): My father's calculators

Back in the early 1980s, I gave my father a Private Pilot's training kit from Cessna. (He would not learn to fly, but he loved nothing better than to study - usually technical stuff.) His training kit included a 12" aluminum E6B. The photos, below, show that calculator and a small paper "Air Navigation Slide Rule" that was in the (plain red plastic) case with the E6B.

Also in the training kit, I found a small ledger-type, bound book in which Dad had made notes on things that he had studied, so I know for certain that he spent many happy hours with that birthday present. Yay! _______________________________________________________

Delightful reading:

1) Basic Slide Rule Instructions from The Museum of HP Calculators 

2) Math with your brain...THE SLIDE RULE from IEEE Entity Web Hosting

3) Scales for Building Your Own Slide Rule from International Slide Rule Museum

4) A history of logs, and A precursor to BMI ;-) from Stu's blog

5) An eBay listing of slide rules for sale which happens to list a 12" P&E slide rule like mine for $39.99 (I've no idea how much mine cost in 1955) and a 6" P&E slide rule like mine for $20 (again, no idea).

More delightful reading from Stu:

1) The Oughtred Society

2) A Most Unusual Slide Rule from Commonsense Design

 

Comments

[Ingineer66]

Very cool collection. Oh the joy that I missed out on, only using slide rules for brief instructional purposes. In high school, I was in the first chemistry class that was allowed to use calculators.

[Ole Phat Stu]

Thank you for letting me contribute :-)

I'll put up some related nostalgia today.

[Cop Car]

Ingineer--Don't weep over what you missed. In years to come, there will be those who lament that they missed out on things/experiences that you took for granted in your younger years.

Stu--You are welcome. Your cooperation is much appreciated. I like your Calculated Nostalgia posting!

[Ingineer66]

Oh I don’t weep. I hated nomographs and everything related to them. I will take an eight or 12 place digitial display every day of the week over analog. 😃

[bogie]

That is an impressive collection. Not that I would know what to do with one (although I'm pretty sure I'm old enough that if I had gone to college after high school, and taken engineering courses, I would have had to learn).

So nice that Grandpa kept that journal so you know that your gift was well appreciated!

[Cop Car]

Ingineer--Whew! I don't need to get out a hanky for you. ; )

Bogie--Supposedly, the last slide rule manufactured in the USA came off the line on 7/11/1976; thus, you are young enough that you, as did Ingineer, would have missed out - even had you gone directly to college following high school and had you majored in engineering. As it was, you were using PDAs by the time you got your bachelor's degree (with a double major, summa cum laude - I exercise a mother's privilege to brag) in your very early 40s.

P.S. I had nearly forgotten that we sometimes called our slide rules "slip sticks".

[bogie]

Well, I didn't get my degree until this century, so calculators were required for some of my math classes. I don't think I used a graphing calculator until I took a class for work ~2008.

[Cop Car]

Bogie--Good point on timing being everything when it came to not needing a slide rule. Thanks!