Today I visited the bank.
Normal every day kind of thing. But…
I was in a hurry and had in my hand an object that I sat on the counter as I signed things. I’d not got it put back in its sleeve. It was a small thing, about 3 inches in diameter (84 mm or 3 5/16 inches). I’d not thought a lot about it. I only had it with me as I’d been working a couple of minor problems (the error bands on cubits) and occasionally needed a bit of help on some of the numbers (like what IS 365/366 x 6.02 compared to 6?)
The clerk, toward the end of the transactions, asked me: What’s that?
He looked and pointed.
I felt old.
It suddenly dawned on me that not only where these things uncommon and maybe even out of fashion, they were now unknown, even to this young man who dealt with numbers all day long and was at least a “20 something”.
It was my “Concise” Circular Slide Rule number N-28:
Available from these folks (who still make them, thank God…) for 1200 yen (about $15 at present Yen rates).
I let it soak in for a moment that I’d done the moral equivalent of showing up in Spats and with a vacuum tube radio… with my horse parked outside…
Then I explained with as much positive manner as I could muster that it was an antique computing device called a “slide rule” and that in ancient times, like when I was in high school, all Engineers, Chemists, Physicists and in fact anyone in Science learned to use them. That we did all our problems on them as there were no calculators “back then”.
He looked fairly interested, so I looked over my shoulder and saw there was no one waiting… And pressed on: “Here is how to multiply 2 x 2. Set this starting mark next to 2, now read off the result next to the other 2.” He said “And it even has Pi on it!” and I said “Yes, see, if we set the index at Pi, all the Pi x anything answers are all displayed at the same time, we just have to pick the one we want. Also, you could want a circle of, oh, 6 inches, and just find 6, then look under it for the diameter…. and it doesnt’ need any batteries and it always works. Fits in my shirt pocket too…”
Then I paused. Expecting the slightly forced smile of someone “tolerating” an elder… Accepting that some folks will always want their movies to be in Black and White but they look harmless enough… What I got was an enthusiastic: “Wow, that’s cool!”
Rarely have I felt so happy in explaining something and never have I been so happy in a bank…
This kid “got it” (“kid”, probably 22?) in about 20 seconds. No chargers, no batteries, plastic and waterproof, works in a hurricane or an earthquake power outage. Lets you SEE the problem not just a row of numbers on a display… I told him what search terms to use in Google to find one if he wanted one (redeeming my place in modern society ;-) and left the bank.
Yes, one of these lives in my “emergency restart the world kit”. One often visits my pocket too. I’ve also got a 6 inch “pocket Pickett” along with the model (NEW in box) that went to The Moon on Apollo as their “backup” to the computers. There are a couple of very large plastic ones that were my ‘day to day’ users and there are the two metal Picketts that were my college and work rules.
I don’t use them as often as I ought. Age means I now have to hunt up my glasses to get more than 2 decimal places of accuracy out of them. But sometimes I take them out. Sometimes I find them on the shelf asking to be “taken for a spin”. Every so often I run some numbers and see if I still remember Avogadro’s Number and can set up a 4 or 5 term equation that then just ‘reads off’ without moving the slide (the art of using multiple markings at once, using the inverted “C” scale creatively…) Or the square and cube scales ( “A” and “K”). Old friends, taken out for a beer at the local pub as we talk about “the old days” when we worked together every day, before they went into that retirement home…
So now I’ve decided to not hide this one when I’m using it. To maybe leave it laying on the counter after figuring tax and tip. To clearly hold it in view while figuring wood needed at the lumber yard. To take my friend to the park, and to the shop, on the way to the pub… And maybe even have him help out on that project I’m building in the back yard… A little Henge time might be good for the ol’ guy. Remind him that there are folks even older than him that still can get in a good days work ;-)
For anyone interested in playing with a slide rule, but not having one at the moment, there is a very interesting curiosity. Folks have made GIFs of the parts and put them in image frames so you can slide them back and forth.
That, of course, is all you need to make a working, real, slide rule. Never mind that the compute power being consumed to do this is orders of magnitude more. Just savor the moment of getting on that DisneyLand Animatronic Horse and taking a little gallop around the track:
A Pickett N-909 – ES (the yellow one). This was my main rule all through college. I still own one of these:
The N-600 S (that small “pocket model” that I have, though mine is white):
And yes, both of those are “working” slide rules that you can manipulate with your mouse.
This guy is even more “into it” than I am, and his site has several (many?) pictures and descriptions:
There is even an International Slide Rule group (though I’m not a member):
And with that, I think I need to acquaint my ‘kids’ with my slide rules so they know not to just pitch them out some day when they inherit them. After all, they are “cool” now ;-)
The front and back of the one that lives in my Doomsday Kit. The Engineering model (3200 yen, 4 5/16 inch so more precise):
The small one that lives in my pocket has a handy set of formulas on the back, but not any working marks:
But unlike the larger one, it does fit fairly easily in a normal shirt pocket.
This link takes you to an “index” page of many other simulations:
Including this one that has numerical readouts for the various scales(!):