Going to the moon (and elsewhere) on slide rules.

[pathology_doc]

As a slide rule addict (and, by way of disclosure, an ordinary member of the Oughtred Society), I'm well aware of the slide rule's proud history in aerospace design and research. Now we know that it almost certainly wasn't all done with slide rules - log and trig tables, mechanical calculators, and later the earliest computers certainly must have played their part when extra precision was required or a lot of numbers needed to be crunched - but a lot of it certainly was.


So here's my question - if you were (or you know/knew) someone involved in the aerospace, guided missile, avionics, etc. industries during the slide rule era, which slide rule did you (or they) use? And just as importantly, if you can tell me, why did you pick that particular model? Do you still have it? Do you still use it?

 

[Michel Van]

i not working in Aerospace.
but i got by second hand a "Aristo 967 U" Slide rule from 1969.
sadly i not use it, dam pocket calculators...

 

[Jemiba]

That's the slide rule, we got at school, early '70s, and actually learned to use it. (Photo from http://it-material.de/2009/03/aristo-0906-rechenschieber/).
On my first job in industry at the beginning of the '80s, it already was nearly completely replaced by the
pocket calculator, although older colleagues still had one in their drawer.
But I know, that sometimes a large slide rule was fixed to the lower edge of a large drawing board,
probably to increase accuracy and make handling of such a large device easier. I remember this very
well, because my father once took me along to his office, and when I was fiddling with this thing, the
cursor suddenly got detached and fall down, the most fragile part of it, as it was made of glass, not
plastic .... my father wasn't amused, of course, but fortunately no damage was done. :-\

 

[Spark]

Hi,
As a student I wanted an Otis King but they cost to much!

As a slide rule addict (and, by way of disclosure, an ordinary member of the Oughtred Society), I'm well aware of the slide rule's proud history in aerospace design and research. Now we know that it almost certainly wasn't all done with slide rules - log and trig tables, mechanical calculators, and later the earliest computers certainly must have played their part when extra precision was required or a lot of numbers needed to be crunched - but a lot of it certainly was.


So here's my question - if you were (or you know/knew) someone involved in the aerospace, guided missile, avionics, etc. industries during the slide rule era, which slide rule did you (or they) use? And just as importantly, if you can tell me, why did you pick that particular model? Do you still have it? Do you still use it?

 

[pathology_doc]

i not working in Aerospace.
but i got by second hand a "Aristo 967 U" Slide rule from 1969.
sadly i not use it, dam pocket calculators...

I have one of those as well! (From e-bay!) Sadly, when it arrived the leaf-spring which maintains tension in the cursor seems to have flown off or gone missing. I have worked out a substitute, so things are ticking along smoothly now.


Spark, Otis Kings are a bad substitute for a linear rule. While they multiply and divide with at least another sf. of accuracy, it's about all they can do. Linear rules are much more versatile and more instinctive. (I own examples of both and speak from experience.)

 

[Bill Walker]

Starting at NIT in Inglewood in the fall of 1970 we all recieved lessons in slide rules, and had to use them in tests for the first year or two. I bought a cheap bamboo one at the school store and never really cared for it. In the summer of 1971 I took all my earnings from a summer job (minus the beer money of course) and bought an HP35. I never looked back. Starting at Canadair Flextrac in the spring of 1974 I got interesting jobs from day one because I had the best calculator in the office .

 

[Arjen]

My two slide rules. The Aristo 903 is a straightforward school slide rule, the Sun Hemmi has a reversible slide that allows some ex
computations in addition to the normal computations of the Aristo.

 

[DSE]

Not the one I learned on in HS, but I inherited a 22" K&E 4080-5 LOG LOG DULPEX TRIG over the years. Also inherited a couple of these. Anyone else have any experience using one of these? Learned to use a much less ornate version in grad school. FWIW, I recently went back to the future, acquiring one of the re-issued HP 15C calculators. Never really got used to or liked the 28S which replaced my original 15C from under/grad school after the dog decided to gnaw on it one day years ago. Sometimes one can go home.

 

[Arjen]

DSE: I hope you'll excuse my ignorance, but I have to ask: what is that intriguing collection of wood and metal bits called? I suppose it is some kind of drawing tool?

 

[Merv_P]

This thread immediately got me thinking of a picture I saw on a book cover years ago in the "Encyclopedia of Science Fiction". I don't have the book any more, but searching - pirates encyclopedia "science fiction" "slide rule" - in Google Images got it straight away.

A classic example of how science fiction gets it wrong.

 

[pathology_doc]

Wrong, yes, but in such a deliciously tongue-in-cheek way that even the hardest of hard SF fans should not try too hard to find fault.


I known of two SF stories in which the character admits to owning or reaches for and uses a 20-inch deci-trig duplex rule. In Heinlein's story (I can't remember the title), he names the brand explicitly (Kueffel and Esser). In E.E. Smith's Skylark Three he doesn't, but it would almost have to be the same type. Heinlein's story is AFAIK set in a not-too-distant future; Smith's is intended to be thought of as being contemporaneous with its publication.

 

[jstar]

Heinlein's story was 'Have spacesuit-Will travel' Here's a link to an interesting site that includes the portion of the story that mentions the K&E.

 

[DSE]

DSE: I hope you'll excuse my ignorance, but I have to ask: what is that intriguing collection of wood and metal bits called? I suppose it is some kind of drawing tool?

Actually, a measurement device known as a compensating polar planimeter. It integrates the area in a closed curve.
PDF containing a description. I first used one in grad school to integrate a measured velocity profile in a pipe which was part of a 20 atm pressurized wind tunnel I helped design, build and calibrate.

 

[Arjen]

First time I've ever heard of it, never mind seeing one. Nice. I'm reminded of what someone told me long ago: the more primitive a measuring device looks, the better its results can be trusted. At the time, we were discussing test results from an obscenely expensive electronic tool and we were not sure
1) what we'd been measuring
2) whether reproducibility and usefulness of data were in any way connected

The electronic thingy had lots of interesting lights and dials, though.

 

[Yellow Palace]

I acquired my father's 10" rule a few years ago, and still use it in anger occasionally. Sometimes a slide rule is quicker than an electronic calculator, and it has the distinct advantages for an engineer that it's almost impossible to read spurious significant figures, whilst requiring you to have an idea what the answer should be. The fact that a 24-year-old graduate engineer can use a slide rule helps to win brownie points with some of the greybeards, too.

Interesting to see what a planimeter looks like - I've heard of them, but never seen one in the flesh.

 

[pathology_doc]

I acquired my father's 10" rule a few years ago, and still use it in anger occasionally.

Conjures up images of naughty children's backsides being paddled with one, back when such was still acceptable. Of course slide rules are (and were) far too precious for that, and the plastic ones wouldn't survive the experience anyway!