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79SuperVert
Samba Member
Joined: May 31, 2002
Posts: 9758
Location: Elizabeth, NJ & La Isla Del Encanto
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 Posted: Thu Jun 27, 2013 6:19 pm Post subject: |
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| babysnakes wrote: |
I remember the old timers challenging each other on barrel crank calculators.
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I've never seen such a thing. Was that for accountants and such?
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Central Jersey VW Society
Wanted: Art Collins VW (Savannah, Georgia) items - license plate surrounds and other items. Also ivory "AM", "FM" and "SW" buttons for a US Blaupunkt Frankfurt. |
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my59
Samba Member
Joined: August 13, 2003
Posts: 3791
Location: connecting the dots
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| Posted: Thu Jun 27, 2013 8:18 pm Post subject: |
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I get working drawings from junior staff that will have a string of dimensions ending in 1/4", 3/8" etc with one dimension showing 16ths, and the over all dimension shows an even eighth or quarter inch.
When I mark up the drawings and tell them to check the math they get all huffy and the answer is usually something along the lines of that's what the computer said the dimensions are. Then they get quiet when I ask em where did the 16th's go.....
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my59: Well son, my grandfather died before I got to drive it, so does that answer your question?
our79: sunroof bus w/camper interior and 2.0 FI
Other:'12 Jetta, '77 Benz 300D, and a 74 MG Midget. |
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Da TOW'D
Samba Member
Joined: December 25, 2005
Posts: 1321
Location: Bella Coma Canada
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| Posted: Thu Jun 27, 2013 8:34 pm Post subject: |
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| 79SuperVert wrote: |
| babysnakes wrote: |
I remember the old timers challenging each other on barrel crank calculators.
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I've never seen such a thing. Was that for accountants and such? |
back in the `60s my navigator used one while we were rallying along with the Reed tables( time and distance)`. He was a math major at UCSB.
we did pretty good and had lots of fun.
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'57 type 1 Blackberry
'58 SC Ruf
'62 type 3 Notch
'92 Eurovan Willy DD
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Culito
11010101
Joined: December 07, 2006
Posts: 5865
Location: Columbia Missourah
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| Posted: Thu Jun 27, 2013 10:54 pm Post subject: |
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I have a nice Post slide rule with case...one of these days I'm going to learn how to use it.
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'64 standard w/2.0L type 4
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| johnnypan wrote: |
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79SuperVert
Samba Member
Joined: May 31, 2002
Posts: 9758
Location: Elizabeth, NJ & La Isla Del Encanto
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| Posted: Fri Jun 28, 2013 5:49 am Post subject: |
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| Culito wrote: |
| I have a nice Post slide rule with case...one of these days I'm going to learn how to use it. |
This is a nice easy to follow presentation on how to use a slide rule.
http://www.sliderulemuseum.com/SR_Course.htm
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Central Jersey VW Society
Wanted: Art Collins VW (Savannah, Georgia) items - license plate surrounds and other items. Also ivory "AM", "FM" and "SW" buttons for a US Blaupunkt Frankfurt. |
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drscope
Samba Member
Joined: February 19, 2007
Posts: 15273
Location: Baltimore, Maryland USA
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| Posted: Fri Jun 28, 2013 7:19 am Post subject: |
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What are you talking about? A slide rule IS a computer!
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Mother Nature is a Mean Evil Bitch! |
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79SuperVert
Samba Member
Joined: May 31, 2002
Posts: 9758
Location: Elizabeth, NJ & La Isla Del Encanto
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| Posted: Fri Jun 28, 2013 8:53 am Post subject: |
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From the SlideRuleMuseum website:
"Prior to 1980, Webster's Dictionary defined the word “COMPUTER” as a PERSON who computes, typically with a slide rule."
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Central Jersey VW Society
Wanted: Art Collins VW (Savannah, Georgia) items - license plate surrounds and other items. Also ivory "AM", "FM" and "SW" buttons for a US Blaupunkt Frankfurt. |
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babysnakes
Samba Member
Joined: August 19, 2008
Posts: 7106
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| Posted: Fri Jun 28, 2013 9:07 am Post subject: |
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| 79SuperVert wrote: |
| babysnakes wrote: |
I remember the old timers challenging each other on barrel crank calculators.
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I've never seen such a thing. Was that for accountants and such? |
These guys were licensed land surveyors and used that for their calc's. I have no clue how to use one. It even has a web site devoted to it.
http://www.curta.org/
If you can find one, they start around $500. |
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KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 34003
Location: Conejo Valley, CA
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| Posted: Fri Jun 28, 2013 9:19 am Post subject: |
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Looks like a cryptex!
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79SuperVert
Samba Member
Joined: May 31, 2002
Posts: 9758
Location: Elizabeth, NJ & La Isla Del Encanto
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| Posted: Fri Jun 28, 2013 10:14 am Post subject: |
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I got a headache reading the extract from the Curta user manual on how to use the machine. It must have been interesting to watch an expert use it.
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Central Jersey VW Society
Wanted: Art Collins VW (Savannah, Georgia) items - license plate surrounds and other items. Also ivory "AM", "FM" and "SW" buttons for a US Blaupunkt Frankfurt. |
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williamM
Samba Member
Joined: August 07, 2008
Posts: 4333
Location: southwest Arizona
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| Posted: Fri Jun 28, 2013 10:49 am Post subject: sounds like |
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B  bet one of those guys invented the Rubrics cube??
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some days I get up and just sit and think. Some days I just sit.
opinion untempered by fact is ignorance.
Don't step in any! |
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babysnakes
Samba Member
Joined: August 19, 2008
Posts: 7106
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| Posted: Fri Jun 28, 2013 8:23 pm Post subject: |
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| 79SuperVert wrote: |
| It must have been interesting to watch an expert use it. |
When I got into land surveying in the early 80's the Curta's were no longer used due to more modern calc. tools. Every few months or so they would bring in their hand cranks and come up with an equation. They would manipulate their devices and see who could come up with the correct result the fastest. It was great fun and very interesting to watch. |
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Gary
Person of Interest
Joined: November 01, 2002
Posts: 17069
Location: 127.0.0.1
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| Posted: Sat Jun 29, 2013 3:32 pm Post subject: |
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My dad was an engineer and retired around 1984 when CAD was coming out. When I was in my early teens, I asked if he used a slide rule. Oh yes, he certainly did and he also mentioned the Trig tables. I always wanted to get the opportunity to learn how to use a slide rule but never did.
One issue I have with schools these days is the teachers who rely on the TI-83 graphing calculators. I know some high schools require them as do some college courses, such as a college algebra course I recently completed for my major. The calculator itself requires its own course in order for someone to understand how to use it. I was happy that the Business Calculus instructor didn't require us to use the TI-83.
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West Virginia State Board of Education v. Barnette, 319 U.S. 624 (1943) |
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e&m_ghia
Samba Member
Joined: April 04, 2011
Posts: 418
Location: NoVA
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| Posted: Sun Jun 30, 2013 8:16 pm Post subject: |
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| 79SuperVert wrote: |
| 2Pack wrote: |
| My understanding is that the slide rule does not tell you where to put the decimal point. I take it that's your point about having to think it through yourself? I see them at flea markets sometimes- I should pick one up for fun. |
Yes, that's true, it doesn't tell you where to put the decimal point. If the problem is kind of simple (like 15.3 x 7) you can sort of guess where the decimal point should be (7 x 20 is 140 and 7 x 10 is 70 so you can guess the answer is going to be somewhere between those numbers).
But if the approximate result is hard to predict (like, say, 1,254 times 0.00237), you can simplify the numbers by converting them to scientific notation and then you don't have to guess. So the numbers above become 1.254 x 10 to the 3rd power times 2.37 x 10 to the -3rd power. The powers of 10 just tell you how many places you have to move the decimal point to get back to the original number.
Then you multiply 1.254 and 2.37 together, and you add the exponents of 10 together, and you end up with 2.97 x 10 to the zero power, or just plain 2.97. |
When I started engineering school in the mid-70's, there were basically 3 kinds of "scientific" calculators: the HP's, the TI's, and the "Bowmar Brains". As I recall, the Bowmars didn't have scientific notation, so they were kind of like slide rules with more digits. They went out of business pretty quickly...
I remember one EE student in my senior classes, who continued to use a slide-rule in class. Sometimes, after finishing an exam, I would sit and watch the guy plug away at complex calculations using his slide rule. I don't recall he did all that badly, just took him a bit longer to get the answers... I wonder if he got the answers more reliably than others, but with a digit or two less precision.
Decimal points... I'm always amused at the proliferation of "decimal point" errors. The factor of 1.E4 is particularly frequent (cm^2 vs. m^2) in the field where I work... Which kind of indicates that people have stopped using their intuitions for orders-of-magnitude... Maybe thinking about magnitude was a good thing.
I haven't used a slide rule since high school, although I remember how to use one - I had a nice K&E slide rule at one time, but it's been lost for many decades... We have a good slide rule, though - my wife inherited her father's yellow metal Pickett, like the ones shown with original posting. |
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