Gene, my father in-law, recently gave this to me as a keepsake. It’s now another one of my prized “old things”. Anyone my age and older will know what it’s called, but I’m guessing some of you under the age of 40 might not be that familiar with it. It’s a slide rule, also known colloquially here in the U.S. as a “slipstick”.
I won’t get in to how a slide rule works and how you use it. Let me just say it’s pretty complicated for someone like me who has depended on an electronic calculator his whole career. If you want to learn how to operate a slide rule, there are plenty of articles on the internet, and I’ll let you borrow this one to practice with!
Quoting from Wikipedia, “The slide rule is used primarily for multiplication and division, and also for functions such as roots, logarithms and trigonometry, but is not normally used for addition or subtraction. Slide rules exist in a diverse range of styles and generally appear in a linear or circular form with a standardized set of markings (scales) essential to performing mathematical computations.”
Slide rules have always fascinated me, and I was pretty excited when Gene gave this one to me. He bought it used, probably in about 1956, from a bookstore in College Station while he was a Mechanical Engineering student at Texas A&M University. While I was at A&M in the late 1970’s, studying to become a Civil Engineer, I remember some of my old professors telling us students how easy we had it, doing advanced calculations with our fancy new electronic calculators!
Think back to the day when you watched or heard about Neil Armstrong walking on the moon, if you were alive then. Believe it or not, most of the intricate calculations that made that amazing feat possible were done with slide rules. The leader of the Apollo space program, Werner Von Braun, was a German rocket scientist who moved to the U.S. after World War 2 to work on the American space effort. When he came here, he brought with him his 1930’s vintage Nestler slide rules, and never once used an electronic calculator in his entire career.
Aluminium Pickett-brand slide rules were carried on the Apollo space missions. The model N600-ES owned by Astronaut Buzz Aldrin that flew with him to the moon on Apollo 11 was sold at auction in 2007. The one taken along on Apollo 13 in 1970 is owned by the National Air and Space Museum.
In the 1950’s and 1960’s, slide rules were carried by just about every practicing engineer. You could identify an engineer by his slide rule in the same way you could tell a doctor by his stethoscope. Gene tells the story about the early years of his career as an engineer, when he and the other young engineers were always “packin'” their slide rules like sidearms in their leather “holsters”, ready to whip it out at any time and perform calculations right there on the spot!
As my professors suggested, I was pretty fortunate to be entering the engineering profession at a time when electronic calculators and personal computers were becoming prevalent. Although there were some staunch slide rule fans who hung on to their weapons well into the late 1970’s, slide rules were rapidly coming to the end of their useful life, starting in the early 70’s. I can remember distinctly when my 7th Grade math teacher, Mr. Lowrance, at Boulter Jr. High in Tyler, had just returned from a teacher’s workshop in Dallas put on by Texas Instruments in the summer of 1974. They were just introducing to the public the first handheld calculator. Mr. Lowrance was fascinated and excited about it, as we all were, and he let us pass it around the room to try it out. If I remember correctly it was this model:
Four functions! 8 digits! Floating decimal point! And MORE! All made right there in Dallas, Texas. That simple little gadget and the ever more capable ones that have come after it, have enabled man to literally change the world over the last 40 years. But let’s not forget that, over 150 years BEFORE the invention of the electronic calculator, mankind achieved amazing things with another type of pocket calculator….the slide rule.
Paul's Point of View 
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