Before There Was Calculators.

G

Grumpy Gator

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Found this round slide rule under the bottom drawer of a Kennedy box. I had a hard enough time learning the basics of a normal slide rule many years ago.
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*********Just Saying**********G*****************
 
The flat disc slide rule works on the exact similar principal to that of the linear slide rule. If you can use a straight linear slide rule you should be able to use type.
A further more accurate slide rule was the drum slide rule used by a lot of Drawing offices. These had the logarithmic scales on the outside of a drum which could have a scale length of 500 " as opposed to the 10" normal straight linear type. Sure was a lot quicker (though not as accurate) as using log / anti-log tables ( 7 fig. tables in the D.O. !)
Happy days !
 
In hi school, I had one of those. As for being accurate, yes and no. In 1972, I took an electronics theory course. In many cases, there were a series of calculations. The guys who spent about 250 bucks for a scientific calculator many times were farther from the answer than I was with my old slip stick. The calculator took it to too many decimal points where as the slide rule would automatically round it off. Mark
 
Ok, are we dating our selves again, Now days I do not think they know how to use a slide rule, (it would take me a little to remember as it has been so long). I had one like that that I used in high school doing engineering and drafting. Of course we had the old T square, Bottled ink with the dropper, and such. None of the fancy stuff.
 
I still have one today use it back in the late 60's
Still works today and battier need

Dave
 
Had one in high school, used one for the first two years of college--couldn't afford a calc. Carried one in my shirt pocket as an engr in gas plants--because it was intrinsically safe. Probably still some chicken scratch on the I-beams of those plants where I was trying to keep track of the decimal points. The good old days. Still have a couple and still use them.
 
i can certainly relate, remembering the first electric calculator we got. . . i think it was a remington. still have my slide rules in the desk.
 
Rule #1, Slide rules need no batteries!
My first really good calculator was an HP35. Reverse polish is better in my opinion..........I miss it still.
 
I grew up using the linear slide rule at University. Mine was a K&E, others preferred the Picket, and there was a laminated bamboo Japanese. My first work term was with a British Engineer and he was using a Curta. I never mastered that one.
https://en.wikipedia.org/wiki/Curta

David
 
I still have my first Picket N902 and the over-the-top Picket N4 Log Log Dual Base Speed Rule along with its holster. I can't remember having used the hyperbolic or log-log scales but I did use the rest of the 29 scales.

One of the problems with linear slide rules was when performing chain multiplications or divisions, you could run off the scale so you had to slide the slide over to the side to continue. The circular slide rule just wrapped around so it eliminated that inconvenience.

I designed and built a custom circular slide rule for my ex, many years ago. It calculated the length of bar stock required to make a horse shoe, based on the dimensions of the horse's hoof. The scales were printed on adhesive backed Mylar and glued to aluminum backing , the product being sold to farriers.

It is amusing to show the slide rule to some of the newer engineers. I like the quizzical looks it generates. Same goes for log and trig tables.
 
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