Yo smart folks .....

J Miller · Post by **J Miller** » Mon Sep 29, 2014 11:19 pm

I found this slide rule in our stuff. No idea in the world how to use it, or what it is used for.

Slide rule composit.JPG

Can one or some of you smart folks educate me on this thing?

Joe

horsesoldier03 · Post by **horsesoldier03** » Mon Sep 29, 2014 11:26 pm

It is all giberish to me, but here is a youtube video.

http://www.youtube.com/watch?v=uUzSStVnAHk

J Miller · Post by **J Miller** » Mon Sep 29, 2014 11:30 pm

horsesoldier03,
Thanks, but unfortunately my dial up and old box won't do You-Tube videos.

Joe

Glenn · Post by **Glenn** » Mon Sep 29, 2014 11:40 pm

It's used for figgerin' out how to get back to earth when yer space ship blows half-way-up in outer space! (See Apollo 13 - the movie)

guido4198 · Post by **guido4198** » Tue Sep 30, 2014 4:57 am

Thanks for the memories....!!!!
I went through College and Graduate school with a couple of slide rules. I'm sure I still have them around somewhere.
It's a fact that in the days before common computer use....Slide Rules were how smart people figured things out.
They were good enough to get us to the moon.
I'm not at all sure that we're better off now, without them.

bdhold · Post by **bdhold** » Tue Sep 30, 2014 5:44 am

multiplication is adding logarithms
division is subtracting logarithms

this stuff is really easy

I used to keep two sheets of semi-log graph paper at the bottom of my stack during math and physics tests so I could "cheat" and make my own slide rule.
Really speeds up the calculation since you only have to carry the calculation in your head far enough to determine the last significant digit or two.

Pisgah · Post by **Pisgah** » Tue Sep 30, 2014 6:13 am

As my sister is fond of saying, "Bro, when the electricity is gone old folks like us will rule the world because we KNOW stuff!"

AJMD429 · Post by **AJMD429** » Tue Sep 30, 2014 6:41 am

bulldog1935 wrote:multiplication is adding logarithms
division is subtracting logarithms

this stuff is really easy

I used to keep two sheets of semi-log graph paper at the bottom of my stack during math and physics tests so I could "cheat" and make my own slide rule.
Really speeds up the calculation since you only have to carry the calculation in your head far enough to determine the last significant digit or two.

What bulldog1935 said.

After spending $40 (about $250 in today's dollars) on a 16" slide rule (longer rulers more accurate and faster to use usually) with lots of extra scales (the main ones do multiplication division and so on, but the others add in trigonometric functions one might use in certain chemistry and electronics or physics applications), my freshman college class was the first one allowed to use electronic calculators. So I never used the slide rule at all...

bdhold · Post by **bdhold** » Tue Sep 30, 2014 7:11 am

absolutely correct about trig functions.

It's also a great engineering tool to convey the concept of significant digits.
1 inch is not 2.54 centimeters, 1.00 inch is.

Something that has been completely lost in the world of calculators and 8 insignificant digits.

And yes, my daughter's favorite tv show is Big Bang Theory (when she was younger, she used to get mad at the teacher when she didn't make 100).

J Miller · Post by **J Miller** » Tue Sep 30, 2014 9:00 am

OK, so then I could, if I knew how, do all sorts of calculations on this thing. So, since I can't do videos is there a text with reference pics instruction sheet somewhere?

I never could understand higher math. Made no sense to me at all. I can do standard math with a pencil and paper, but that's all.

Back in 71-72 when I had my first year of college they were just starting that "New Math" stuff that really messed with your brains. It ruined me for anything else.

Joe

Mescalero · Post by **Mescalero** » Tue Sep 30, 2014 9:06 am

Mine still has the " how to " book with it.
I guess I could try to copy it.

bmtshooter · Post by **bmtshooter** » Tue Sep 30, 2014 9:08 am

Think of it as an analog calculator. Works great ........ never needs batteries. Some of us surely remember how expensive the first electronic hand - held calculators were. Now they are throw away items. Isn't it strange how printer cartridges are so expensive by comparison?

bdhold · Post by **bdhold** » Tue Sep 30, 2014 9:57 am

3 x 8 = 24

pick two adjacent sliding scales (if you can recognize it, they should both be log scales - use scale A and scale B in your first photo)
slide the cursor (black lines on clear slider) over to 3 on the top scale (scale A)
slide the zero on the bottom scale to the cursor (scale B)
move the cursor over to 8 on the bottom scale (scale B)
the answer is at the cursor on the top scale - 24 (scale A)
you're geometrically adding the logarithms of 3 and 8 to measure the logarithm of the product

all that math stuff really works - it's real world and doesn't become abstract until you get i in the picture.

stretch · Post by **stretch** » Tue Sep 30, 2014 10:35 am

I never learnt haow to use a slide rule, because affordable
calculators came in just in time for high school. That said,
I don't own a calculator now. I do the stuff in my head when possible,
because I feel that it keeps the old grey matter working in my
dotage.

A the old Lockheed Skunk Works, the SR-71 was designed in less than
a year without computers. Just slide rules and the like. I believe it still
holds the trans-Atlantic, the trans-Continental(North America), and some
other speed records. The P-38 Lightning was designed the same way by the
same outfit in WWII. Good engineering works, and is NOT dependent on
computers!

-Stretch

J Miller · Post by **J Miller** » Tue Sep 30, 2014 11:05 am

Bulldog,

Ummm, trying to do what you said, but .... there is no "0" anywhere on these scales. Numbers 1 through 9 but no 0. Am I blind or is the old brain just not working here?

Joe

bdhold · Post by **bdhold** » Tue Sep 30, 2014 11:09 am

of course, the physical "zero" is numerically 1 on the slide rule - in this case, it represents multiplying by 1 - you get the same number

J Miller · Post by **J Miller** » Tue Sep 30, 2014 11:28 am

bulldog1935 wrote:of course, the physical "zero" is numerically 1 on the slide rule - in this case, it represents multiplying by 1 - you get the same number

OOOK, I was looking at the wrong end of the rule to start with, then I didn't know the 1 at the end represented 0 but once you clarified that I found the 2 and the 4 marks that represent 24.
I'll try some other things and see what I come up with.

Mescalero wrote:Mine still has the " how to " book with it.
I guess I could try to copy it.

I'd really appreciate it. Maybe I can learn something

Joe

JohndeFresno · Post by **JohndeFresno** » Tue Sep 30, 2014 11:35 am

Joe,
No offense intended, but the smart folks use an app on their phone or 'puter or one of them things called a calculator.

The brilliant folks get the smart folks to figure out this stuff and then take all the credit (like Georg Luger, Alexander G. Bell, George Westinghouse).

The enlightened ones shoot old revolvers and leverguns and things and don't worry about that stuff.

Blaine · Post by **Blaine** » Tue Sep 30, 2014 11:53 am

Decimal degrees, minutes, seconds & tenths of feet are the easiest calculations. ....logs were a gift of the math gods

jnyork · Post by **jnyork** » Tue Sep 30, 2014 12:52 pm

USAF Flight Engineer school in 1969, prep to serve on EC-121's, we had about 6 weeks on nothing but slide rule for 4 hours a day, remainder of the day on aircraft performance. 4 hours average homework every night. At the end of training we could whip on just about anything you could dream up that could be done on the slide rule. (I wont go into the old joke about the constipated mathematician who worked it out with a slide rule)

Anyway, I came across it a few months ago while searching through an old footlocker. Couldn't remember how to do the most simple calculations. Now, where did I put that electronic calculator?

J Miller · Post by **J Miller** » Tue Sep 30, 2014 1:00 pm

My wife has a fancy calculator that can do any math you want. It makes ZERO sense to me. I can't use it.

I don't have a smart phone, mines stupid. It don't take pics or do the internet or cook my breakfast or start my car for me as my flight is approaching the airport. It just makes phone calls.

Slide rules are something I've never had the chance to mess with so this is different to me.

If I learn something good. If not then fall back and punt.

Joe

KiwiKev · Post by **KiwiKev** » Tue Sep 30, 2014 2:21 pm

I have one of these which is like a circular slide rule for pilots. A Rotary clone - not a Breitling

I need a magnifying glass to read - my eyes!

I think my year may have been the first not to use slide rules- I remember my brother cursing over his. But I did learn how to use one. They are quite cool and good for building brain power.

MacEntyre · Post by **MacEntyre** » Tue Sep 30, 2014 3:20 pm

Mescalero wrote:Mine still has the " how to " book with it.
I guess I could try to copy it.

JMiller, get instructions here, from Amazon.com:
http://www.amazon.com/s/?ie=UTF8&keywor ... par4h9p9_e

...or here, from WikiHow: http://www.wikihow.com/Use-a-Slide-Rule

There are lots of other sites with instructions, if you search for "How to use a slide rule"

Hawkeye2 · Post by **Hawkeye2** » Tue Sep 30, 2014 4:39 pm

When I went off to college in the fall of '62 I was carrying a new Pickett magnesium slide rule which cost me a week's pay. You could tell an engineering student a quarter mile or more away because we all wore a slide rule hung from our belt. I remember on fellow who had a chess piece, a knight, on his slide rule case, can anyone guess what TV show was very popular at the time? When I worked in a lab at Pratt & Whitney (United Aircraft) in the late 60's we did all our calculations on a slide rule with the exception of a few. The lab had a mechanical desktop calculator which was about the size of two and a half typewriters and probably weighed as much as a Buick. It was mechanical like a giant adding machine and if I remember it went to 8 decimal places and we would have used scientific notation.

1894c · Post by **1894c** » Tue Sep 30, 2014 5:18 pm

it was at this point in our story when my brain unexpectedly switched off...ONLY KIDDING...well kind-of... :)

Buck Elliott · Post by **Buck Elliott** » Tue Sep 30, 2014 6:32 pm

I still have my old K&E log-log-duplex-decitrig slide rule that I used in High School and College. it was my Dad's, and was passed along to me.. It is made of closely-milled bamboo, with inlaid celluloid faces. i still trot it out from time to time, although my TI calculators are handier for most things..

Back in the mid-late 70s, my neighbor came up with a new HP pocket calculator - about the size of a cigarette pack - that featured Addition, Substraction, Multiplication and Division, and cost him the enormous sum of $650.. !!

Grizz · Post by **Grizz** » Tue Sep 30, 2014 7:01 pm

I still have my cheapo hs slide rule. I offered it to my son if he would pass it on the dna chain.

Ho Hum.

As I said, I still have my old slide rule....

Old Ironsights · Post by **Old Ironsights** » Tue Sep 30, 2014 7:16 pm

J Miller wrote:OK, so then I could, if I knew how, do all sorts of calculations on this thing. So, since I can't do videos is there a text with reference pics instruction sheet somewhere?
...Joe

http://www.oughtred.org/
http://www.oughtred.org/books/AllAboutS ... 121001.pdf
http://sliderulemuseum.com/SR_Course.htm

Though, by the looks of your 'rule, I think you would find learning on it horribly frustrating. Your cursor/hairline is not True/calibrated. it would make even the most simple calcs an exercise in head banging.

But, since you collect Pens and old sewing machines, I think slide rules would be right up your alley.

AJMD429 · Post by **AJMD429** » Tue Sep 30, 2014 7:19 pm

JohndeFresno wrote:Joe,
No offense intended, but the smart folks use an app on their phone or 'puter or one of them things called a calculator.

The brilliant folks get the smart folks to figure out this stuff and then take all the credit (like Georg Luger, Alexander G. Bell, George Westinghouse).

The enlightened ones shoot old revolvers and leverguns and things and don't worry about that stuff.

I agree 100%...

Old Ironsights · Post by **Old Ironsights** » Tue Sep 30, 2014 7:29 pm

Here's a "virtual Sliderule" to play with...

Hawkeye2 wrote:When I went off to college in the fall of '62 I was carrying a new Pickett magnesium slide rule which cost me a week's pay. You could tell an engineering student a quarter mile or more away because we all wore a slide rule hung from our belt. ...

Back to my set:

The belt-scabbard Versalogs are great, but the Pocket Protector Versalog/KE 4181-1 is handier/geekier...

Joe: If you really want to learn, I will trade you my Sterling Mannheim Rule (The green & white plastic one in the middle) for the one you have. The one you have looks to be a folded plastic Trade-Show unit. If you take me up on it, I'll research it and tell you if there is any collector value. If not, I'll call it even. If there is Value beyond the trade, I'll negotiate with you to Buy it or swap back.

Interested?

J Miller · Post by **J Miller** » Tue Sep 30, 2014 10:19 pm

OI,

I've seen one like the yellow virtual slide rule you posted above. Not sure where, but I've seen one.

As for the trade offer I'll mention it to my wife. The little plastic one I'm playing with is hers.

Joe

Old Ironsights · Post by **Old Ironsights** » Tue Sep 30, 2014 10:23 pm

The Yellow design is/was, IIRC a Trademark of Pickett. They made some really nice metal Rules. Click on the pic and it will link you to a real-time interactive simulator. Should work even over dialup.

92&94 · Post by **92&94** » Wed Oct 01, 2014 8:54 am

In my box of drafting stuff is a slide rule, probably my dad's. I never had much inclination to figure it out, but now I almost do

After years and years of math, trig is the only thing I've used regularly outside of school

J Miller · Post by **J Miller** » Wed Oct 01, 2014 10:26 am

Old Ironsights wrote:Here's a "virtual Sliderule" to play with...

Hawkeye2 wrote:When I went off to college in the fall of '62 I was carrying a new Pickett magnesium slide rule which cost me a week's pay. You could tell an engineering student a quarter mile or more away because we all wore a slide rule hung from our belt. ...
Back to my set:

The belt-scabbard Versalogs are great, but the Pocket Protector Versalog/KE 4181-1 is handier/geekier...

Joe: If you really want to learn, I will trade you my Sterling Mannheim Rule (The green & white plastic one in the middle) for the one you have. The one you have looks to be a folded plastic Trade-Show unit. If you take me up on it, I'll research it and tell you if there is any collector value. If not, I'll call it even. If there is Value beyond the trade, I'll negotiate with you to Buy it or swap back.

Interested?

OI,
Sent you a PM.

Joe

piller · Post by **piller** » Wed Oct 01, 2014 10:40 am

My Dad still has his slide rules and still knows how to use them. He Graduated High School in 1947. His older brother used a slide rule to figure out where the warheads from the Trident would impact. A good slide rule and an engineer who knows which end is up can do some amazing stuff.

When I was in High School, I had a TI55 that cleared all its memory when you turned it off. It used a red LED display and had rechargeable battery packs. It could do anything that I needed up through Physics 202 in college.

Pete44ru · Post by **Pete44ru** » Wed Oct 01, 2014 3:09 pm

J Miller wrote:
Since I can't do videos is there a text with reference pics instruction sheet somewhere?

Join a local Public Library, which can have a copy transferred in (usually free) if they don't have a book about them (speak to the librarian).

.

J Miller · Post by **J Miller** » Wed Oct 01, 2014 4:58 pm

Library? Do they still have those? What with the internet I thought they did away with those.

Joe

JohndeFresno · Post by **JohndeFresno** » Fri Oct 03, 2014 11:09 am

Joe,
I found a really practical use for your equipment in the downloadable classic reloading book cited earlier:
https://app.box.com/s/h2or5r4ot9zno8o57frg

The Complete Guide to Handloading by Phil Sharpe, now searchable, a 197MB file... "With dial-ups, you probably should click on the download at bedtime and then pick it up when you awaken."

I know that you use dial-up, but this one 468 page download is worth the effort, I believe. I just takes a bit of time.

Specifically, Chapter XXXIV "Practical Handloading Computations with the Slide Rule," starting on page 324, you are shown some practical use of that device. After the introduction of who did what (Mr. Napier's discovery of logarithms, etc.), the next page (325) starts out with using your slider to figure out the volume of a bullet. Set one slider to the first number of the equation, then next slide to the multiplier shown in the equation, read the number in another part, and so on. Step by step.

Hopefully, this image will load for you:

Several ballistic equations are given. I suspect that I will be off the net for a while. Thanks again to WM for finding this gem. Enjoy.

John

Panzercat · Post by **Panzercat** » Sat Oct 04, 2014 5:20 pm

Yo, I got one of those. Picked it up at the goodwill

J Miller · Post by **J Miller** » Sun Oct 05, 2014 10:21 am

I got a hard copy of Phillip Sharpes book. No need to download it. I doubt my modem would stay connected long enough to do it anyway.

I just got to find it.

Joe

Old Ironsights · Post by **Old Ironsights** » Sun Oct 05, 2014 10:24 am

JohndeFresno wrote:Joe,
I found a really practical use for your equipment in the downloadable classic reloading book cited earlier:
https://app.box.com/s/h2or5r4ot9zno8o57frg

The Complete Guide to Handloading by Phil Sharpe, now searchable, a 197MB file... ...
Several ballistic equations are given. I suspect that I will be off the net for a while. Thanks again to WM for finding this gem. Enjoy.

John

That is cool. Thanks.

Bill in Oregon · Post by **Bill in Oregon** » Mon Oct 06, 2014 9:05 am

Growing up in Tacoma in the 60s, a lot of my friends' dads worked for Boeing, and boy, could they run slide rules. And when it came time for the Cub Scout Pinewood Derby, the Boeing kids' cars looked so cool and ran so well, it gave me an inferiority complex ...