Still love your old slide rule? This guy was obsessed

I spent many months flunking out of Undergraduate Navigator Training at Mather AFB CA in the early 80’s. They eventually made good on their threat of what fate would befall those who did not pack the gear to be a Navigator by making me a cop and sending me to Minot.

I had to give back my beloved whiz wheel, which was almost as painful as returning the cool red switchblade we got. I believe it is a slide rule that goes roundy-round.
 

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Not sure how many know this, but the iPhone calculator app, when vertical is a standard calculator; when you hold your phone horizontal, it changes to a scientific calculator.
 

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I wonder if he calculated the date of his death on any of those slide rules.
 
oldbrownhat said:
Walter Shawlee, the Sovereign of Slide Rules, Is Dead at 73

Used by engineers for centuries, they were displaced by pocket calculators and all but forgotten until Mr. Shawlee created a subculture of obsessives and cornered the market.

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Walter Shawlee displayed some of his slide rules at his home in British Columbia in 1999. Beside him was a reproduction of Robby the Robot, a character in the movie “Forbidden Planet.” Ms. Shawlee called it “our unofficial mascot.” It’s unclear if the robot knew how to use a slide rule

One day... a middle-aged avionics engineer by the name of Walter Shawlee was looking through a drawer at his home in Kelowna, a midsize city in British Columbia, when he happened upon his old slide rule from high school.
It was a Keuffel & Esser pocket Deci-Lon, model 68-1130, with a slender Ivorite body and delicate see-through cursor box. Both had stood the test of time. Mr. Shawlee remembered that as a teenager he had spent six months saving up money to buy it.

Inspired by this encounter with his youth, he created a website dedicated to slide rules. Before long, nostalgic math whizzes of decades past came across the site. Emails poured into Mr. Shawlee’s inbox. He began spending eight hours a day researching, buying, fixing and reselling old slide rules...

...“He’s Mr. Slide Rule,” a Texas engineer and slide-rule enthusiast told The Journal. “Walter knows everybody in the slide-rule racket.”

...In the early 2000s, he was earning $125,000 a year fixing and reselling slide rules. The business paid for his two children to go to college, and it sent one of them to law school. His customer base took its most organized form in the Oughtred Society, a club named in honor of William Oughtred, the Anglican minister generally recognized to have invented the slide rule in the early 1620s...
Click to expand...

A man after my own heart!
 
Dad had and used a slide rule. He bought a Ti1200 in the 70's. It didn't have as many feature as the 1250, in fact, it was pretty basic, but he couldn't afford much. Later we found out they were the same thing with different metal plates on the front. If you pried up the metal plate, the other functions could be used.
 

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Somewhere….. I still have one. I used to write formulas in side for tests. That didn’t seem like cheating to me back then. I also recall putting my new calculator in my arm pit to warm the dead battery!
 
The Big Three slide rule makers back in the day were K&E, Pickett, and Post. I still have two K&Es, short (I think 5") for pocket carry and long (10"). Also have a 10" Pickett, made of aluminum alloy. My small K&E is all plastic and I keep it in my truck glove box. Occasionally I use it for figuring gas mileage. Back in my college teaching days, I once taught a course for Freshmen engineering students on how to use a slide rule. Digital calculators had not yet been invented, so mastery of the slide rule was considered to be an essential skill for aspiring engineers. In one of my early jobs, my engineering group had an extra-long slide rule, about 2' I think, to perform more precise calculations if the situation demanded it. There were also several types of circular slide rules. I never was very enamored with them but some engineers did prefer them to the linear type. One weakness of slide rules was that you could not add and subtract with them, but they were good for trig, calculating compound interest, taking numbers to powers, logarithms, ratios and proportions, etc., that you could not do easily with the early electronic digital calculators. Incidentally, Walter Shawlee has a very close resemblance to me as I appeared in my younger days.
 
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sigp220.45 said:
I spent many months flunking out of Undergraduate Navigator Training at Mather AFB CA in the early 80’s. They eventually made good on their threat of what fate would befall those who did not pack the gear to be a Navigator by making me a cop and sending me to Minot.

I had to give back my beloved whiz wheel, which was almost as painful as returning the cool red switchblade we got. I believe it is a slide rule that goes roundy-round.
Click to expand...

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Mrs. swig's late brother was a C-46 pilot in WW 2. Here is his "simplified" flight calculator. I guess the navigators got the complex versions. I'm pretty sure his wasn't made in Korea!

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My dad was a Chemical Engineer for the Navy, and did design work on nuclear submarines in the late 1950s with a slide rule (which I now have). Even though calculators were available before he retired, I don't think he ever used one...
 
There were many special slide rules made for specific applications. I once found one at a garage sale that was designed for the purpose of calculating load distributions inside a C-54 cargo plane to balance the load. I suppose it it was something that an Air Force loadmaster would have used. I never attempted to figure out how it worked. Today, there are much better means for performing those types of calculations.
 
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I took the last class.......

...offered by my school in slide rule. One year it was a required course and next year it was defunct. I thought the slide rule was really neat UNLESS you had a scientic calculator with a lot of functions. About every notebook had a table of trig sines, cosines and tangents built in that came in handy before we took slide rule. A calculator made it a snap.
 
My father-in-law was a NASA engineer. Computers existed but were expensive to use and slow so most of the work that got us to the moon was done with slide rule.
 
This discussion brought to mind the Engineer's Cheer that I learned as a Freshman.

e to the x, dy, dx
e to the x, dx
three point one four one five nine
cosine secant tangent sine
cube root square root BTU
slip stick, slide rule
Yea Purdue!
 
I used a slide rule for my 3 years of electronics classes. Later, in the early 70's when Bowmar introduced the Bowmar Brain, I cheerfully pitched the slide rule in the trash. The Bowmar came out during my compound angles trig class and the instructor said we could use it for homework and tests. The night of the final exam, I handed my test in 30 minutes after receiving it and the instructor looked perplexed. No one had ever handed in an exam early before (it was a 4 hour class). After checking my answers, he shrugged and said I could leave. I bet the next year's class either had a lot more questions or weren't allowed calculators.

That Bowmar Brain had 5 functions: add, subtract, multiply, divide and percentages. At the time, it set me back $80 which was a considerable sum back then, but it was so worth it. It eliminated mistakes when doing "simple math" that so often tripped me up. Later on when Texas Instrument came out with a calculator that had all the trig tables built in, I thought I had died and gone to heaven.

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