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Senior Advisor

Slide Rule

I remember in 1973 I bought a Sears 4 function calculator at the cost of $100.  Before that, I had sometimes but not regularly used a slide rule.  I never carried one around in those holsters that the engineering students used along with their pocket protector.  

We pilots use a circular slide rule called an E6B, at least in training.  Some farm applications have circular slide rules.

 

Did you used to use a slipsitck?  What and where and why?  Don't worry, you'll be showing your age so ignore it. 

 

The slide rule wasn't as good at adding so sometimes we used one of those things with lots of wheels on it that you turned with a stylus.  Oh, how far we have come.  

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Advisor

Re: Slide Rule

I watched a PBS show the other night about the group of intelligence workers in Britain during WWII who interpreted pictures through an ingenious system of 3D photos.  They created the 3D by having pilots take two different fly overs of the target at specified degrees of variance.  Then they used a very sophisticated machine that was able to calibrate and determine dimensions so precise they could actually tell allied bombers exactly where to put the bombs with their bomb-sights.  They discovered the German secrets before anyone else did.  The V-1 and V-2 rockets, not to mention the doodlebug cruise missile, were discovered by them.  These details of their efforts have only recently been declassified. 

 

 

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Advisor

Re: Slide Rule

Oh, by the way, I bought a Sears calculator about the same time as you.  Used it for many years.  Yep.  It dates me as well.

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Senior Advisor

Re: Slide Rule

The V-1 was nicknamed as the "buzz bomb" and "doodlebug" partly because of the noise of the pulse jet engine used and the leaping or jumping way it flew in response to the pulses.  Aerial reconaissance is interesiting, isn't it?

I think the CIA has tried for 40 years to estimate crop production in closed counttries from satellites.  I don't know how wel lthey do.  Probably not to close. 

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Veteran Advisor

Re: Slide Rule

I've been VERY lucky to have great-uncles (brothers to my Grandfather) who decided I needed an 'education' in case this new-fangled technology goes haywire.

I learned to use a slide ruler, even took it to grade school once, aced a test in no time in 8th grade, when the teacher had a 'no calculator' test.  I was done in maybe half the time anyone else was.  Teacher was sure I cheated somehow, and I outright told her 'I used this' and showed her the slide rule (this was a one-room schoolhouse, one of the very last of its kind, by the way).  The teacher looked at it, and didn't know what it was!  She called my house, and mom answered, and when I got home, mom had a good laugh out of having to explain what a slide ruler was to my teacher, but I wasn't supposed to take it to class anymore. 

I also have harnessed draft horses, and setup the belt drives on old thrashing machines, buzz saws, and such.  My grandpa even had a lineshaft in his old shop.  The guy at the Stuhr Museum in Grand Island was giving old-time sawmill demonstrations, and was asking us there questions, and I knew the answers to every one (why is the pulley widest in the middle, why do some belts cross, and others don't, etc. 

I know what 'advance the spark' and 'open the shutters' means, too.

The only problem, unless I go to some antique show, that knowledge is pretty much useless.

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Advisor

Re: Slide Rule

Yes, it is very interesting.  I believe we are losing the technical battle in our classrooms these days.  Lately, most great scientific minds come from other countries.  Our math scores are in decline, so are educational standards, though somehow we are confronted with rising scores, and yet, they cannot do great work at our colleges and universities.  A landlord that works in a major aircraft company says new recruits are desparately lacking in basic knowledge that entry level employees need, just to work at that level.

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Honored Advisor

Re: Slide Rule

We must have bought the same calculator, same specs, same price, same year. 

 

Whoever thought they would out-do the slide rules we toted to physics and calculus class?  Do you recall extreapoliating logarithms from the charts in the back of the book, too?  Sometimes wish I had pursued the math major I was recruited for...but, if wishes were horses, beggars would ride. 

 

We had one teacher in eleventh grade who was such a nerd, his tiepin bar was a tiny slide rule.  Now, the graphing calculators that display the equations in colors are awesome; but, many kids have no idea if their calculator answer to 1+1 is close to right or not., 

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Frequent Contributor

Re: Slide Rule

I just checked. There are two slide rules in my desk drawer. That probably tells you more about my housekeeping than my math abilities. When I did my masters in 1968 I had to do 50 square root calculations.I rented a Totalia mechanical calculator for $50 for a month. The calculations took less than a week. I then had it to play with. I was so impressed my dad offered to buy it for me. Luckily I thought I had better places to spend the $500. Four years later I bought a Unicom electronic calculator for $100. I still have it. It would still work but the screen is scratched up too bad to be readable. My how times have changed. My 11 year old grandson is doing algebra, something I did not start until high school!....Soyroy 

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Veteran Advisor

Re: Slide Rule

I agree.  If you want proof, watch the average person under 30 try to make change.

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Veteran Advisor

Re: Slide Rule


@Roy_Smith wrote:

I just checked. There are two slide rules in my desk drawer. That probably tells you more about my housekeeping than my math abilities. When I did my masters in 1968 I had to do 50 square root calculations.I rented a Totalia mechanical calculator for $50 for a month. The calculations took less than a week. I then had it to play with. I was so impressed my dad offered to buy it for me. Luckily I thought I had better places to spend the $500. Four years later I bought a Unicom electronic calculator for $100. I still have it. It would still work but the screen is scratched up too bad to be readable. My how times have changed. My 11 year old grandson is doing algebra, something I did not start until high school!....Soyroy 


That was before I was even born!

 

When did calculators really take off?  I remember some people having them, all through grade school, but my parents didn't want be to be dependant on a machine, so I couldn't have one until Algebra, but I could use the slide ruler.

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