A time when slide-rules ruled

No! This is not a review about the great Nevil Shute novel with the same name, but a musing about the object itself. The book itself was Shute’s own autobiography, and quite an engrossing one at that. For serious readers, Nevil Shute is always a recommendation, books like his ‘Town like Alice’& ‘On the beach’ standout novels.

I still remember the fist time I saw one of them beauties, a slide rule (not the gals), after I joined the engineering college. I had not the faintest clue that such a thing existed till I saw one and held it in my hands, and the one I saw was a lovely Faber Castell off-white contraption. It took a while before somebody explained how it worked and it took many days before I figured out the rudiments of slide-ruling.

As it was a necessity (until then we had managed famously with the Log tables), I pestered my uncle, a shippie to get me one, and he did. That was how I came to possess a ‘Hope 530’ Made in Japan - Slide rule. Straight away I stuck my name tag on the plastic box. I became fairly conversant with its use after many months of frustration but was never fluent like others who could complete complex calculations in a flourish. Today, after many decades, I saw it in the bottom shelf of our storage room and I wondered, was the calculator that came in the 70’s worth it? The slide rule, working based on logarithms, had by then crossed three hundred years of continuous use!! People like Neil Armstrong & Jimmy Crater were slide rule users. But admittedly, it required much training & it was still very complicated to go past two decimals, only a few had such mastery to get there.

Those were the things that set an engineer apart those days and a little higher up in the hierarchy. We carried the T square (later the mini drafter), drawing instruments (rivaling the medico’s guy’s stethoscope) and the Slide rule in style, confident in the fact that nobody would know what to do with them, and right we were.

The HP and Texas instrument calculators came soon after, the Texas machines had a nice red display and what they called positive sequence keying or something like that (you felt that click after you pressed a button – never to be seen on Japanese machines) while all the others (Japanese) had blue or green displays. Exams were completed faster, and in the early days many a calculator was stolen as they were almost always imported and much in demand.

I pestered my uncle again and he brought me a ‘thundering’ Casio device (FX102) with a blue LED display, not LCD, slightly clunky compared to today’s stuff. Man! That was like a Ford Mustang, did everything it was asked in lightning speed, used normal AA batteries and had 12 digits. And with that the slide rule hit the dust, consigned to the bottom of my trunk.

Today I looked at the relic slide rule with great fondness as it brought back many a college memory, of early teen age days gone by, new friendships, the ragging period, the first days of independent hostel living….remember the Tamil song in ‘Autograph’ Nyapakam varuthe nyapakm varuthe…. Today I can still operate the slide-rule, multiplying numbers for example, while my son looks on bewildered (otherwise he has tons of things to say on how backward we were) and awed…It required acquired skill, it needed no batteries, girls took time learning it, so the boys had ample opportunity getting up and closer training them ….

The slide rule is an extremely clever device that uses logarithms to simplify difficult calculations. It was invented in the 17th century by the British mathematician, William Oughtred. He realized that one could multiply or divide numbers by sliding two logarithmically marked rulers next to one another. Subsequent refinements added many more sophisticated functions and developed slide rules for highly specialized types of calculations. Users ranged from NASA engineers working on the Apollo Project to sanitation engineers, to artillerymen.

There was a movie in 1952 titled – Slide Rule Blonde – now that is something very irregular

And there is a great song by Sam Cooke– ‘Wonderful world’ which goes like this

Don't know much about geography
Don't know much trigonometry
Don't know much about algebra
Don't know what a slide rule is for.
But I do know that one and one is two,
And if this one could be with you,
What a wonderful world this would be.

And some reasons why it beats a computer hollow

-A Slide Rule doesn't shut down abruptly when it gets too hot
-A Slide Rule doesn't smoke whenever the power supply hiccups
-You can spill coffee on a Slide Rule; you can use a Slide Rule while completely submerged in coffee or wherever
-A Slide Rule doesn't need scheduled hardware maintenance
-A Slide Rule is immune to viruses, worms, and other depredations from hostile adolescents with telephones
-Slide Rules are designed to a standardized, open architecture


Nanditha Prabhu said...

and informative as usual!
so how many girls did you get close to with the "slide rule"?

Naveen Prabhu said...

very informative post sir ... i belong to your son's generation and we were allowed scientific calculators in exam halls ...

i guess the cmptrs and gadgets have in a way prvented us frm acquiring the skills which came naturally to you .... perhaps the idea of "getting closer" to the gals could do the trick if propagated in school .. :-)

Bhel Puri & Seekh Kabab said...

Nice post. It's the same with the abacus. A lot of Chinese shopkeepers still swear by it.

diyadear said...

hey hats off to a true engineer.. i sumtimes feel im not a proper engineer at all.. (though i have the lame excuse of being a software one) nowadays even for simple multiplication we tend to use a calculator.. is it really advancement?? :(

Lakshmi Bharadwaj said...

Interesting...I think this person called naveen is right. We do use logorithms in colleges now, but to a limited extent, and sometimes, we even find simple logorithms to be difficult. My Phy teacher is complaining that the present day generation is loosing out on Analytical skills because we are allowed calculators, big time. I had never heard of slide-rules, thanks for educating me. It's such a coincidence that I had my phy lab exam today, and I used log tables, when someone on the net is talking about logorithm tables and slide rules!

Maddy said...

nanditha -well ell, i did anticipate that, you can see i stated that i was not so adpet, to be a trainer!!
naveen - i used it only for one year..then moved on to the fx102.
BPSK - Ababcus - I know of it, but have not handled one - glad you enjoyed it.
Diya - my son asked me- you are an engineer but i dont see you doing equations and research and all that - you are talking marketing, sales, figures!! well i was at a loss for words, myself.
Lakshmi - I know, i tell my sons - The human race will mutate & evolve as darwin says. Eventually we will have mainly a brain plus a large set of hands with lots of 6pack muscles in our fingers after typing on phones, calculators, keyboards etc...

Maddy said...

A friend of mine mailed me an interesting link which allows you to interactively play with a slide rule (both sides!). So anybody interested can try it out!!


Happy Kitten said...

Girls took longer time.. in general? do I see a typical MCP comment out here?

just joking..

Maddy said...

HK - well, that was the lead for the punch line actually. But then, you must realise that in those days we had probabaly 3 girls max in a class of 50 and about 10 in a batch of 500. I guess they were overwhelmed, albeit initially!!