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Lost Knowledge - Digital Calculator

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Remember these?




Just for the fun of it, I decided to rejuvenate my ability to use a slide rule. I have time to spare while between courtesy bus trips from the Club, so I thought I would put the time to good use. I realised that I needed an instruction book in physical form because if I had it on my iPad, the battery would soon go flat.


I went to my local Council library and searched its on-line catalogue using the words "slide rule". In just a snap, I got the reply: "No Match".


Imagine that! What would these blokes who designed the Apollo Mission space craft think?




I know that all us aviators can use a navigation slide rule, but what about the great unwashed masses? How are they going to maintain these ancient skills? We need to show the younger generations how to use the digital calculators we had when a chip was something that came off the Old Block.


The loss of this knowledge recalls a story by Isaac Asimov in which the world's calculating computers go on the fritz causing a major economic catastrophe because financial calculations cannot be done. The situation is saved by a backroom bod who has been doodling with pencil and paper and has taught himself basic mathematics.


We must revive these skills! Failure to do so exposes our Society to the return of ignorance and barbarism.




It's not logical, Jim.







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Not so new!


Otis Carter Formby King (1876–1944) was a grocer and engineer in London who invented and produced a cylindrical slide rule with helical scales, primarily for business uses initially. The product was named Otis King's Patent Calculator, and was manufactured and sold by Carbic Ltd. in London from about 1922 to about 1972.


With a log-scale decade length of 66 inches, the Otis King calculator should be about a full digit more accurate than a 6-inch pocket slide rule. But due to inaccuracies in tic-mark placement, some portions of its scales will read off by more than they should. For example, a reading of 4.630 might represent an answer of 4.632, or almost one part in 2000 error, when it should be accurate to one part in 6000 (66"/6000 = 0.011" estimated interpolation accuracy).[1]



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