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Perry Hilbert Jr
01-16-2019, 5:54 PM
My daughter came into my office and asked to use a ruler. Sure top drawer of the Credenza. She opens it and picks up a slide rule, looks at it briefly and says what does this measure. Well it doesn't measure anything, it is a calculator. No really what does it do? It is a calculator. I answer. So she says: Here show me how to do 22 x 9. So I show her. Then come all the questions about how it works, and what else it can do. And of course it has been forever since I really used one. She lost interest, or so I thought, and then a couple hours later, I over hear her on the phone, telling a friend about the slide ruler and it multiplies and divides without batteries. .......

Bill Orbine
01-16-2019, 6:08 PM
To be honest, I have a couple slide rulers and I never learned to use them. The cheap calculators came out just in time!

Ken Fitzgerald
01-16-2019, 6:20 PM
I was using slide rules until the first HP scientific calculators that used reverse polar notation came out. Due to an advertising mistake I got one for really reduced price.

John K Jordan
01-16-2019, 6:22 PM
Yes, I have several and still use one on occasion. There was a thread recently about slide rules.

lowell holmes
01-16-2019, 6:23 PM
I have both, but I don't know where the slide rule is.

Alan Rutherford
01-16-2019, 6:49 PM
I know how to use one.

Several years ago I was visiting a local private school with my son and his mother to see if we wanted him to go there, probably around 7th grade. The Math teacher had a slide rule on his desk for some reason. I showed him how to use it. Son went elsewhere.

Lee DeRaud
01-16-2019, 7:46 PM
Slide rule...isn't that the one where the runner isn't allowed to do a rolling block into second base to break up a double play? :)

(I'm old enough to remember when most math classrooms had a huge Pickett slide rule mounted on the wall behind the teacher's desk. Apparently they gave them out free to schools that bought large quantities of the normal-sized ones.)

Stan Calow
01-16-2019, 7:56 PM
I've been picking up nice ones at estate sales. I only remember how to multiply and divide. Yeah we had one of those giant ones in the chemistry lab in high school.

lowell holmes
01-16-2019, 7:59 PM
If I were still working, I would have one. I had a 10" and a 6".
I would go inside refineries and chemical companies to do field work.
Maybe I will buy another one just because . . . . .....

Marty Gulseth
01-16-2019, 8:26 PM
I bumbled through all four years of engineering school using a slide rule. Yep, I’m THAT old! I sincerely believe that, had I had a “modern” scientific calculator, my GPA would have been a full point higher...

Bruce Wrenn
01-16-2019, 8:28 PM
Never forget that the first moon missions calculations were done on a slide rule. Still have mine.

Ron Citerone
01-16-2019, 8:29 PM
In my Junior Year in High School I used one for Chemistry, in my Senior year Physics we had calculators and never picked up a slide rule again.......1975, 1976

Lee Schierer
01-16-2019, 9:02 PM
I still have my slide rule. We were issued one at the naval Academy and I used it all 4 years. I switched to a calculator in 1972 but still did sines and cosine, etc on the slide rule it was more convenient than a book of tables. My grandkids didn't believe me when I said you could multiply and divide with it. I used to have a circular one but I don't know what happened to it.

Paul F Franklin
01-16-2019, 9:55 PM
The HP scientific calculator came out while I was a JR or SR in high school, but no way I could afford one. I made it through a year or two of engineering school using my dad's slide rule. Then TI introduced a more reasonably priced scientific calculator (SR50?) and I made the leap. As I recall, there was quite a bit of controversy at the time about allowing students to use calculators on exams and such. It was seen as a fairness issue because of the cost. But once the TI model came out the concern pretty much evaporated.

Tom Stenzel
01-16-2019, 10:46 PM
In my desk drawer at work I kept a few things to terrorize the apprentices with, beam power pentodes, force motors from obsolete equipment and other really obtuse things. Of course I had a slide rule in there and insisted that before they would succeed they would have to an expert with one. Well, physical abuse was out so the hazing became mental!

Still have my first calculator a Casio Fx-10. Still works and the blue fluorescent display is easy to read.

http://www.vintagecalculators.com/html/casio_fx-10.html

-Tom

Matt Mattingley
01-16-2019, 10:50 PM
So I’m intrigued to see one of these side rule calculators too. I am must be a little bit too young. As I was growing up we used what was called as a magic square. I use A dozen or so slide rules with different information in the shop every day. Sure, Google search engine has made most of these obsolete.
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Mike Henderson
01-16-2019, 11:12 PM
I went through my entire college career (electrical engineering) with a slide rule - hand held calculators were not really available. We could use the mainframe for certain calculations but, of course, not for tests. I was pretty good on the slide rule and knew how do just about all the different calculations you could do on one. I had my initials put on my slide rule so I could claim mine when we did group study and everybody had the same Post slide rule.

I still have mine but I doubt if I could remember how to do anything more than multiply on it.

Mike

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Bruce Page
01-16-2019, 11:19 PM
My dad taught me how to use one when I was a kid. I doubt I could remember how to do it today.
Here’s his pre digital age Curta “pepper mill” calculator that I inherited from him. It’s an amazing piece of machinery and pretty valuable to collectors.

Matt Mattingley
01-16-2019, 11:27 PM
I went through my entire college career (electrical engineering) with a slide rule - hand held calculators were not really available. We could use the mainframe for certain calculations but, of course, not for tests. I was pretty good on the slide rule and knew how do just about all the different calculations you could do on one. I had my initials put on my slide rule so I could claim mine when we did group study and everybody had the same Post slide rule.

I still have mine but I doubt if I could remember how to do anything more than multiply on it.

Mike

401434 Mike, thank you and wow! Now you’ve got me wanting one of them.

Keith Westfall
01-16-2019, 11:37 PM
My dad used a slide rule, even taught me a bit on it a looonnnngggggg time ago. For many many years he carried a small 4" circular one in his pocket. He could figure almost anything on it. I think I still have his slide rule, and he used to have (and use) the pepper grinder style as well. He loved his toys...

Jim Koepke
01-17-2019, 1:12 AM
One of my slide rules is actually a tie clip. It is a working 2" slide rule.

jtk

Charlie Velasquez
01-17-2019, 8:51 AM
yellow Pickett

I can still remember the first day of high school physics class, our teacher told us we all had to have one. We gathered around him as he showed us the various models in a catalog.
We had a couple of days to make a selection and bring in the money, he ordered them at a school discount.
12" aluminum body with a leather case.
Later got a another 12" with a plastic body and a 6" one to carry around with me.

Perry Hilbert Jr
01-17-2019, 10:32 AM
The one I had in high school in the 1960's was just a plastic one from a local store that sold some more specialized school supplies. The beginning of my Sr. year, I purchased a much fancier one at a college book store in the next town over. a few years later about 1974, I was attending a conference at Bucknell University and ran into an acquaintance who was an engineering student there. (we were on competing rifle teams) He was wearing a leather pouch on his belt almost the size of a cigar box. WTH is that? I asked him. He said it is a new electronic calculator. He was so excited about it. He showed me several of the functions. And it was truly an amazing thing. He had worked all summer just to buy the calculator for his engineering classes. A year later, a calculator that did the same things was a mere $200 and today a $8.00 calculator can do the same.

John K Jordan
01-17-2019, 12:21 PM
The one I had in high school in the 1960's was just a plastic one from a local store that sold some more specialized school supplies. The beginning of my Sr. year, I purchased a much fancier one at a college book store in the next town over. a few years later about 1974, I was attending a conference at Bucknell University and ran into an acquaintance who was an engineering student there. (we were on competing rifle teams) He was wearing a leather pouch on his belt almost the size of a cigar box. WTH is that? I asked him. He said it is a new electronic calculator. He was so excited about it. He showed me several of the functions. And it was truly an amazing thing. He had worked all summer just to buy the calculator for his engineering classes. A year later, a calculator that did the same things was a mere $200 and today a $8.00 calculator can do the same.

I also have a circular slide rule, required when I got my pilot's training. They probably use calculators now. A friend used a circular slide rule in graduate school when working on his physics PHD - he said he worked it with his left hand with a pencil his right.

Another piece of slide rule trivia - all the technical classrooms in colleges and many high schools had a huge teaching slide rule on the front wall above the blackboard.

As for calculators, I once had one with basic scientific functions (and MEMORY) in a cabinet maybe 2' wide and 3' tall with keyboard and nixie tube display. The memory was a big mechanical spiral in the cabinet - a piezoelectric transducer sent vibrations down the spiral representing the number to be stored. A sensor at the end detected the vibrations and a cabinet full of electronics decoded and recovered the number when needed, and constantly refreshed the signals so they would come around again.

Some info and photos for the inquisitive geek:
https://en.wikipedia.org/wiki/Delay_line_memory

JKJ

Lee DeRaud
01-17-2019, 1:29 PM
a few years later about 1974, I was attending a conference at Bucknell University and ran into an acquaintance who was an engineering student there. (we were on competing rifle teams) He was wearing a leather pouch on his belt almost the size of a cigar box. WTH is that? I asked him. He said it is a new electronic calculator.That timing sounds off: the (normal-size) HP35 scientific calculator came out in 1972. (My senior year, '71-'72, HP gave beta-test units to everyone in the engineering school, and replaced them with production units at graduation.)

Perry Hilbert Jr
01-17-2019, 1:39 PM
Might have been as early as 1970, that is when I first started intercolliegate competition where I would have met him. He was on Bucknell's team. I finished in college in 1973. But attended a conference there after graduation, so perhaps earlier.

Jason Roehl
01-18-2019, 8:17 AM
I was using slide rules until the first HP scientific calculators that used reverse polar notation came out. Due to an advertising mistake I got one for really reduced price.

I have an HP 42S in the desk drawer (RPN) that I've had for about 28 years, and an HP 42S simulator app on my smartphone. RPN lives!

roger wiegand
01-18-2019, 8:50 AM
I had the great good fortune of an uncle who was a physicist who believed that kids should be taught mathematics before the school system convinced them it was difficult. One afternoon when I was in the 4th grade he told me all about logarithms and how you could multiply and divide by adding and subtracting them. The notion has been intuitive ever since and I used a slide rule from that day until the point in grad school when we could afford an electronic calculator-- a plug-in-the-wall device the size of a shoebox that would only add subtract, multiply, and divide, and cost about $600. A year later the first HP calculators appeared and it was history.

Another vote for RPN-- I've never figured out how to use the other kind, the order of entry is just wrong. Who thinks "48, now what operation do I want do do, OK, divide, now by what, OK 12 then think again to actually do the operation by pushing equals?" (if all the rest of you think that way, break it to me gently!) For the record, my thought process is "48, 12, divide".

Rod Sheridan
01-18-2019, 9:00 AM
I can remember how to multiply and divide with a slide rule, however all else is lost to me.

My first calculator was an RPN one, then an HP 33E, I'm still using my HP 11C.

The 11C is theft proof, it sits on my desk at work, and if someone borrows it, they come back with it asking where the equals key is..........LOL.

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Ole Anderson
01-18-2019, 9:48 AM
Yep, got two. One is my dad’s from college, Michigan State class of 1933. I would be hard pressed to do much more than multiplication now. Last time used professionally about 1970.

John Stankus
01-18-2019, 1:47 PM
I...

Another piece of slide rule trivia - all the technical classrooms in colleges and many high schools had a huge teaching slide rule on the front wall above the blackboard.

...

JKJ


with apologies to Crocodile Dundee

That's not a slide rule, this is a slide rule.

I do have a five or six inch slide rule I hand to students who forget their calculator.:)

Andrew Seemann
01-18-2019, 2:29 PM
35 or so years ago in school we used slide rules for a couple weeks as part of learning about logarithms. The math teacher handed them out a the beginning of class and collected them at the end. Only time I have ever used one. I did like the concept though; you get a better idea of the limitations of precision in a practical sense. One of my irritations in the analytical world is people who don't understand concept of significant figures.

Lee DeRaud
01-18-2019, 2:55 PM
with apologies to Crocodile Dundee

That's not a slide rule, this is a slide rule.The real problem with these is that there's no belt-loop on the case.
401563

John K Jordan
01-18-2019, 5:06 PM
with apologies to Crocodile Dundee
That's not a slide rule, this is a slide rule.


Man, I'd drive half way across the country for one of those!
Somewhere I still have a working slide rule on a tie clip. The two would look great together.

As Andrew implied, one huge value of learning to do engineering calculations on the slide rule is it naturally helps you to understand significant figures. Teachers sigh at the student who divides three significant digits by two and writes down 10 digits from the calculator. And is 1200 two, three, or four significant figures? Another value is it forces you to think of magnitudes - does 1.51 really mean .00151 or 151 or 1.51x10^4 - what makes sense?

I keep these by my figurin' nest, mostly to enrich the education of young people when talking about math and science. One is a cheap plastic Pickett and the other is a high end K&E, double sided, precision slide, beautiful engraving, leather case - a wonderful machine.

401573
Scales: K, A, B, T, S, ST, S, D, L, DF, CF, CIF, CI, C, LL1, LL2, LL3, LL01, LL02, LL03 and an extra D.
I can't remember what most of those scales are for and some I never even knew.

JKJ

Andrew DiLorenzo
01-18-2019, 6:05 PM
I have one and can use it. I also have numerous TI calculators and have tutored on them to people just learning.

Jim Allen
01-18-2019, 6:22 PM
I sold the 2 I had last year on eBay....

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Ronald Blue
01-18-2019, 7:17 PM
That timing sounds off: the (normal-size) HP35 scientific calculator came out in 1972. (My senior year, '71-'72, HP gave beta-test units to everyone in the engineering school, and replaced them with production units at graduation.)

You are correct Lee.

Introduced on February 1 1972, the Hewlett-Packard HP-35 was the first handheld electronic calculator sold by HP, and the first handheld ever to perform logarithmic and trigonometric functions with one keystroke. In effect it was the world's first electronic slide rule. As opposed to later HP calculators, it has an xy function, not yx, and the trigonometric functions work in degrees only. It does not have a shift key like later models, but there is an ARC key for use with SIN, COS, and TAN to give their inverses. The story goes that it was made after William Hewlett was shown the HP9100 desktop calculator by his engineers, and asked for a version to fit in his shirt-pocket. At first, HP thought they would only make a few HP-35s for their own engineers, as no-one else would be interested. Then they decided to try selling it - and sold hundreds of thousands. The HP-35 is of special interest to collectors because it was the first HP handheld, and the world's first handheld calculator with transcendental functions, so I give more details of it than of other models.

http://www.vintagecalculators.com/assets/images/HP35_1.JPG
Hewlett-Packard HP-35.

Thomas Canfield
01-18-2019, 7:28 PM
Graduating with BSME in Jan'65, slide rules were the only game in town. No calculators and computers were only the key punch card main frame just coming into use, and not accessible. Of course, I had to also walk uphill both ways to/from all my 8:00 AM classes 6 days a week, for 4 years. That's right, 8:00 Saturday classes every semester.

Bill McNiel
01-18-2019, 7:47 PM
Yes, I still have mine. Slide Rule was required in my High School math classes and essential for Structures Class (3 years) in Architectural School (no relevant HP calculators at that time). All I can currently do with it now is multiply and divide.

Mark Blatter
01-18-2019, 8:28 PM
You are correct Lee.

Introduced on February 1 1972, the Hewlett-Packard HP-35 was the first handheld electronic calculator sold by HP, and the first handheld ever to perform logarithmic and trigonometric functions with one keystroke. In effect it was the world's first electronic slide rule. As opposed to later HP calculators, it has an xy function, not yx, and the trigonometric functions work in degrees only. It does not have a shift key like later models, but there is an ARC key for use with SIN, COS, and TAN to give their inverses. The story goes that it was made after William Hewlett was shown the HP9100 desktop calculator by his engineers, and asked for a version to fit in his shirt-pocket. At first, HP thought they would only make a few HP-35s for their own engineers, as no-one else would be interested. Then they decided to try selling it - and sold hundreds of thousands. The HP-35 is of special interest to collectors because it was the first HP handheld, and the world's first handheld calculator with transcendental functions, so I give more details of it than of other models.

http://www.vintagecalculators.com/assets/images/HP35_1.JPG
Hewlett-Packard HP-35.



I used a slide rule a bit in jr high, then in high school, was able to afford an HP. I think it was an HP 45 and it cost me about $200. In jr high, all the cool kids carried around slide rules in their shirt pockets, or pants pocket and whip them out and use them. Then high school, you were so not cool if you had to use a slide rule. I loved the HP (RPN) and anyone that used a TI was made fun of because they weren't real engineering calculators.

That reminds me of my 9th grade science teacher. He had lost most of one thumb somehow but always made a point of still using it to count. He would count to five using his non-existent thumb and four fingers, holding up that hand. It always looked funny, saying five, but only holding up four. He did it to get kids to pay attention I think.

Ole Anderson
01-19-2019, 8:19 AM
Both my dad's and my slide rule were K&E's. the bamboo ones with plastic faces. My first calculator was a TI30
https://encrypted-tbn0.gstatic.com/shopping?q=tbn:ANd9GcS5_4lcaAZ0sV-w2bKmkAWL-15P02pN2epjBYn_Hhq4KWNxusxstpWmaQxUVFG9X6YmMa8p4yZ et5T4ORvnVcln5buUlLISHg7ywW-o5RCdEWR7LNAYggoK&usqp=CAc
Speaking of mainframes. the MSU computer center had a Control Data 3600. I spent a lot of time in 1966 perfecting and printing out basic trig tables, each page was one degree, rows were one minute, columns were 10 seconds. 90 pages per book. Wish I would have kept at least one page from each book. All data entry was on punch cards.

John Stankus
01-19-2019, 12:42 PM
with apologies to Crocodile Dundee

That's not a slide rule, this is a slide rule.

I do have a five or six inch slide rule I hand to students who forget their calculator.:)

I’ll have to take a few close up pictures highlighting the woodworking in the large slide rule when I am back in the office Tuesday. I am guessing the wood is mahogany

John

John Stankus
02-04-2019, 11:49 AM
Took me a little longer than I expected to take the photos.

402761402762402763402764

It looks to be made of mahogany. I didn't realize until I took the photos that there was an angle scale on the reverse of the slider.

John

Roger Feeley
02-04-2019, 12:07 PM
I think I will teach my grandson to use a slide rule when he's old enough. I like the idea of touching your work. I still have and use a Vemco drafting machine. I guess that makes me old fashioned but there's something to be said for engaging other senses.

I hear that the SCUBA instructors aren't teaching the decompression tables anymore. They just hand you a dive computer and tell you to do what it says. Hmmmph. I don't carry the tables in my head and would certainly use a computer but I'm thinking that it would be hard to truly grasp how nitrogen builds up and outgasses without at least some passing experience.

By the same token, teaching logarithms with a slide rule seems like a great tactile experience.

John K Jordan
02-04-2019, 2:14 PM
I hear that the SCUBA instructors aren't teaching the decompression tables anymore. They just hand you a dive computer and tell you to do what it says. Hmmmph. I don't carry the tables in my head and would certainly use a computer but I'm thinking that it would be hard to truly grasp how nitrogen builds up and outgasses without at least some passing experience.


Yikes, what happens when the thing breaks just when you need it? Sport divers shouldn't need decompression anyway, just follow the no-decompression depth/time limits. But always carry a table.

During my years of cave diving we had to make decompression stops after deep dives, sometimes more than one. In particular, one of our favorite dives require going to over 100' before the "real" dive even started. I can tell you it sure gets chilly waiting and incredibly boring at the stops, even in the "warm" Florida springs and even when wearing a good dry suit with an insulated layers. We got so bored there were practical jokes played.

JKJ

Steve Demuth
02-10-2019, 6:12 PM
I saved all summer in 1973 to raise $395 for an HP35 to replace my slide rule at the beginning of the 1973 school year, but by the time I had the money to order it (from an ad on, I think, the last page of August 1973 Scientific American), HP had introduced the HP45, and so that ended up being my first electronic slide rule. I still have two of them, both work, but one has several missing LED segments, so isn't terribly useful. I use an HP45 simulator on my cell phone when I need a calculator for the occasional shop calculation (typically simple trigonometry).

I also have the slide rule that the HP45 replaced.

As long as we're reminiscing about HP - in 1976 we took delivery of HP 2640A ASCII CRT terminals. HP built a character mode terminal with a backplane that took add-in cards for storage and other purposes. They came with a program you could run an an HP 3000 minicomputer (for which the 2640 was designed) to download diagnostics to the 2640. We hacked the download, and figured out how to program the 2640 - basically turned them into an early personal computer, 5 years before the IBM PC, 2 before the Apple II, and contemporary with the early backplane personal computers like the IMSAI.

Fast forward to today, when there are entire computers, complete with batteries and Bluetooth Low Energy communications that fit in the margin of a contact lens and can be used to monitor glucose levels in tears, or focus the lens with piezoelectric components.

Osvaldo Cristo
02-11-2019, 2:41 PM
My daughter came into my office and asked to use a ruler. Sure top drawer of the Credenza. She opens it and picks up a slide rule, looks at it briefly and says what does this measure. Well it doesn't measure anything, it is a calculator. No really what does it do? It is a calculator. I answer. So she says: Here show me how to do 22 x 9. So I show her. Then come all the questions about how it works, and what else it can do. And of course it has been forever since I really used one. She lost interest, or so I thought, and then a couple hours later, I over hear her on the phone, telling a friend about the slide ruler and it multiplies and divides without batteries. .......

Oh yes - once a time I was very good to use these slide rules, actually the two I had is over my table now, my regular size Faber Castel 2/83 and my pocket sized Aristo 868, both made in Germany. I remind my richer colleagues used Japanese ones. I got the transition between slide rules and scientific calculator and probably I was the last one to use one at the Engineering graduation! They were fully replaced only on 1981 by my HP 15C, also in one of my desk drawers but unfortunately had its battery pins felt out when I tried to change its batteries a couple of months ago... but the slide rules are working great!

Another thing I learned how to create and I used a few times were alignment charts... I think nobody use them since 1960s...