I wanted to show our g daughters what we used for a calculator before electronic calculators came into existence, but it has developed a fault.
Faber Castell is the maker and the two fixed scales look to have bent towards each other, making the slide difficult to move. I have tried putting a bit of hard soap on the slide, but that has not improved things very much.
Can anyone offer any advice on this problem?
Dave
Stick with the calculator
Tony
How wonderfully helpful!
Dave, If the slide rule is a wooden one, there is sometimes a spring deliberately designed to push the A & D scales together to compensate for natural movement in the sliding section. Graphite from a B pencil rubbed on the sliding surfaces can be helpful.
If you start your lesson with two linear rulers as an adding machine, you can then build on that to illustrate multiplication by 'adding' two logarithmic scales.
Bob
They won't be interested!
Thanks for that. I'll take a look later.
I'm not sure about the two rule idea, as that might be a step too far for them, as they are only 6 and 9 years old. The idea is to show how to do simple multiplication and division. e.g. 6 divided by 2 = ?
2 * 2 = ?. After that, I might go onto squaring a number.Dave
Well, maybe. But when I was sixteen or so, we found a big box of slide rules in the back of a cupboard in our old physics classroom. The teacher explained what they were (for some people) and how to use one (for all of us). Everyone was interested, and about half of us were sufficiently intrigued to use one instead of a calculator for the rest of the double lesson.
Couldn't remember it now though :-)
Pete
I wouldn't bet on it. I think my lad would be fascinated, daughter might show some vague interest, she likes maths. Show them the Apollo 13 movie where ground control are busy checking the final burn calculations, using slide rules. We went to the moon before electronic calculators where common place.
And Jim Lovell went on to say that he had previously failed at maths as the 4 slide rules went to work checking his gimble data conversions.
Dave
Failing that, try this one:
Before we used slide rules, it was books of tables. Gawd, those interpolation columns... Can you find yours and use that?
(Can you still buy such things? I'd be surprised if anyone is still printing them.)
Mine are right here on the shelf. I *think* I can remember...
Hmmm. Amazon have books *containing* such tables, in print. But they're basically books on other subjects, with tables included.
A couple of years back, I decided I would like a slide rule but had long since lost my school one (British Thornton). Picked one up on ebay, complete with original box and instructions and P&P for under 10 quid.
I found that even not having used one for over 30 years, I still remembered exactly how to use it.
Well, it would be very easy to print them off on a computer...
The best such book (I have a copy) is the "Science Data Book" editted by RM Tennent. It has the common tables plus a huge amount about materials, chemistry, physics, common formulae etc.
Well I was happy to have a copy but notice that, if you want one now, it's a bloody antique!
candle wax
My old slide rule is still in good condition although some of the numbers are a bit worn.
The mention of logs reminded me that I still have the tables, I don't need to use them any more (don't use a calculator either for the basic sums I can do in my head) but I loved any excuse to use them when at school. They were fascinating!
Mary
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Liquorice" saying something like:
Indeed, and the most famous slide rule scene before that was at the squash court in Chicago where Enrico Fermi was hand-caculating the expected neutron activity of the experimental pile for the several stages of rod withdrawal. His slide rule predictions were impressively accurate.
Yes, Documenta Geigy for example. And the "electronic" versions such as the formulae built in to Excel are less accurate. The best electronic packages fall back on lookup tables for calculations involving small numbers because it's more accurate than the Gaussian approximations used for large data sets.
A very quick look at Amazon shows lots of Documenta Geigy - but not, I think, new. That is, they might be in new condition but not as in new from the publishers. Obviously, my quick look at Amazon is not definitive and someone, somewhere might just be doing so. But I did see "Plane and Spherical Trigonometry and Four-Place Tables of Logarithms" by William Anthony Granville as a newly published edition.
With the history of Excel's mathematics, I wouldn't wish to trust it for anything vitally important. And I am perfectly content for packages to use any viable technique - including lookups - so long as it is reliable.
I remember that clip - amazing!
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.