5 ms·

Oughtred Society Archive of Slide Rule Collections

38 points by richardjam73 3y ago

mschaef 3y ago
It's really worth looking at a few of the collections. There are lots of slide rules on display, and many if not most are far beyond plain linear slide rules. (Most are special purpose and application specific.)
- ghaff 3y ago
  Cardboard slide rules of various times--often used as advertising--used to be very common for calculations and/or lookup tables.
  - sheepshear 3y ago
    There are still a few companies that make them. Called "slide charts", since they come in many forms besides just the "rule" form. I look into having them made every now and then, but it seems like the minimum order quantity is almost universally 500. It would be nice if there was a modern style of e-print service for smaller quantities.
- quercusa 3y ago
  Blackbody Radiaton Slide Rule: https://osgalleries.org/collectors/davis/info_and_image.cgi?string1=blackbody&string2=2251 https://osgalleries.org/collectors/davis/info_and_image.cgi?...
dudeinjapan 3y ago
Just like some people prefer vinyl over digital audio, I've always felt my division is warmer when using a slide rule.
- deleted 3y ago
  [deleted]
ftio 3y ago
I knew exactly what this website would look like just by reading the title. Absolutely perfect. Form elevated to content.
coldpie 3y ago
I inherited two or three slide rules from my father. One of them is circular shaped. Once or twice he showed me how to do some basic calculations, and I've spent ten minutes here and there with various online tutorials, but I've never put the time in to actually understand it, so I always instantly forget how they work. Kind of a shame, but I hang on to them anyway. They're cool artifacts from the pre-computer world. Hm, I wonder if it could be a handy way to do fractional computation while I'm doing woodworking? If so, that could be a good excuse to finally learn how to use one. (Strangely, my work's proxy blocks this domain as "pornography." Interpret that as you will.)
- toast0 3y ago
  Most slide rules will do many operations, but the basic operation is multiplication. Multiplication on a slide rule works because you can turn multiplication into addition with X * Y = 10 ^ (log(X) + log(Y)) (Edit: i had e and ln up here, but 10 and log is a better match the slide rules from 1 to 10l The rules are log scaled, so you find X on one rule and line up 1 on the other rule, then look at what number on the first rule is where Y is on the second rule. Run a couple examples you know the answer to, and you'll get it. As I recall, wrapping/bounding is tricky, you might need to reverse X and Y or go the opposite way to get your answer. You'll need to do it like scientific notation as well, the rules only have numbers between 1 and 10. Division is inverted multiplication, so for X / Y, line up the rules so X and Y match, the quotient is what is on the X rule where Y is 1. I don't know much about woodworking, are you doing multiplication or division with fractions, or adding? Do you want fractional results or decimals?
  - coldpie 3y ago
    Thanks! Usually adding and division. For example "7 3/4 plus 8 1/8" or "15 3/4 divided by 4." Fractional result would be ideal. I don't know if a sliderule is a good tool for this is or not :)
    - toast0 3y ago
      I think a slide rule isn't going to help much... You'll still need to do the addition, and then you'd need to eyeball 15 3/4 as a number between 1 and 2, do the division, and then eyeball the result into a fraction. I think I've only seen decimal marked slide rules, you could certainly have a fraction marked rule, but it wouldn't be that helpful, because 15 3/4 is not easy to turn into 10 * (1 + 1/2 + 3/4 * 1/5 ) And then you're not at a power of two fraction anymore either. Some other tool would be better; probably a pocket calculator that's taken advantage of half a century of computational advances and can manage fractions.
denton-scratch 3y ago
At school I was introduced to several calculation aids: * Slide rule * Mechanical adder * IBM Schools Computer The IBM wasn't actually much of an aid; it had no persistent storage, and you had to program it in hex, from the console. The mechanical adder was marvelous; you toggled in the arguments using metal wheels, and then cranked a handle on the side to do additions. We actually used them to do sums; there was a cupboard in the maths classroom, with enough machines to have one on each desk. My father left me a Faber slide rule from the twenties. Wood, with ivory lamination, and a nice, delicately-sprung cursor. We never used slide rules at school to do computations, we only used them to learn how to use slide rules (which was therefore a complete waste of time).
sleepybrett 3y ago
I feel like being gen x i might have been part of the first wave of kids never to learn to use a slide rule. I'm actually not even totally clear on what they are even for. I am really digging some of the other mechanical calculators in the collections though. Always love to see a curta.
- BoiledCabbage 3y ago
  > I'm actually not even totally clear on what they are even for. The same way you can pick a point on amap, measure a certain distance away on the map and "automatically" know how far away to locations are in really life - you can pick a number on a side rule, move a certain distance away and it will "automatically" multiply or divide two numbers. It will have a small amount of error in it, the same way measuring distance on a map will have a small amount of error in it.
ararar 3y ago
Concise Co. of Japan still makes slide rulers albeit only circular ones (https://www.sliderule.tokyo/products/list.php https://www.sliderule.tokyo/products/list.php). One prominent industry that still uses slide rulers is aviation. They use "flight computers".
- twic 3y ago
  I suppose pilots often have good eyesight and wear gloves, which makes a slide rule easier to use than a calculator with buttons.
OldGuyInTheClub 3y ago
I've been meaning to dust off my old slide rule for a long time. Learning to use one circa 8th grade made future science so much easier. Had to think of significant figures ahead of time, spend a few moments to plan the computation, and get comfortable with when to approximate and how. Pretty soon I was able to get a sense for what answers ought to be, at least to within a factor of 2-5. Anything outside of that and I knew I'd made a mistake somewhere. I also loved the old HP calculators of the late 1970s to late 1980s and eventually set the slipstick aside but am ever grateful for what it did for me. And for fellow RPNthusiasts, there is the Museum of HP Calculators at https://hpmuseum.org/ https://hpmuseum.org/

38 points by richardjam73 3y ago

It's really worth looking at a few of the collections. There are lots of slide rules on display, and many if not most are far beyond plain linear slide rules. (Most are special purpose and application specific.)

ghaff 3y ago
Cardboard slide rules of various times--often used as advertising--used to be very common for calculations and/or lookup tables.
- sheepshear 3y ago
  There are still a few companies that make them. Called "slide charts", since they come in many forms besides just the "rule" form. I look into having them made every now and then, but it seems like the minimum order quantity is almost universally 500. It would be nice if there was a modern style of e-print service for smaller quantities.
quercusa 3y ago
Blackbody Radiaton Slide Rule: https://osgalleries.org/collectors/davis/info_and_image.cgi?string1=blackbody&string2=2251 https://osgalleries.org/collectors/davis/info_and_image.cgi?...

dudeinjapan 3y ago

Just like some people prefer vinyl over digital audio, I've always felt my division is warmer when using a slide rule.

deleted 3y ago
[deleted]

ftio 3y ago

I knew exactly what this website would look like just by reading the title. Absolutely perfect. Form elevated to content.

coldpie 3y ago

I inherited two or three slide rules from my father. One of them is circular shaped. Once or twice he showed me how to do some basic calculations, and I've spent ten minutes here and there with various online tutorials, but I've never put the time in to actually understand it, so I always instantly forget how they work. Kind of a shame, but I hang on to them anyway. They're cool artifacts from the pre-computer world. Hm, I wonder if it could be a handy way to do fractional computation while I'm doing woodworking? If so, that could be a good excuse to finally learn how to use one. (Strangely, my work's proxy blocks this domain as "pornography." Interpret that as you will.)

toast0 3y ago
Most slide rules will do many operations, but the basic operation is multiplication. Multiplication on a slide rule works because you can turn multiplication into addition with X * Y = 10 ^ (log(X) + log(Y)) (Edit: i had e and ln up here, but 10 and log is a better match the slide rules from 1 to 10l The rules are log scaled, so you find X on one rule and line up 1 on the other rule, then look at what number on the first rule is where Y is on the second rule. Run a couple examples you know the answer to, and you'll get it. As I recall, wrapping/bounding is tricky, you might need to reverse X and Y or go the opposite way to get your answer. You'll need to do it like scientific notation as well, the rules only have numbers between 1 and 10. Division is inverted multiplication, so for X / Y, line up the rules so X and Y match, the quotient is what is on the X rule where Y is 1. I don't know much about woodworking, are you doing multiplication or division with fractions, or adding? Do you want fractional results or decimals?
- coldpie 3y ago
  Thanks! Usually adding and division. For example "7 3/4 plus 8 1/8" or "15 3/4 divided by 4." Fractional result would be ideal. I don't know if a sliderule is a good tool for this is or not :)
  - toast0 3y ago
    I think a slide rule isn't going to help much... You'll still need to do the addition, and then you'd need to eyeball 15 3/4 as a number between 1 and 2, do the division, and then eyeball the result into a fraction. I think I've only seen decimal marked slide rules, you could certainly have a fraction marked rule, but it wouldn't be that helpful, because 15 3/4 is not easy to turn into 10 * (1 + 1/2 + 3/4 * 1/5 ) And then you're not at a power of two fraction anymore either. Some other tool would be better; probably a pocket calculator that's taken advantage of half a century of computational advances and can manage fractions.

denton-scratch 3y ago

At school I was introduced to several calculation aids: * Slide rule * Mechanical adder * IBM Schools Computer The IBM wasn't actually much of an aid; it had no persistent storage, and you had to program it in hex, from the console. The mechanical adder was marvelous; you toggled in the arguments using metal wheels, and then cranked a handle on the side to do additions. We actually used them to do sums; there was a cupboard in the maths classroom, with enough machines to have one on each desk. My father left me a Faber slide rule from the twenties. Wood, with ivory lamination, and a nice, delicately-sprung cursor. We never used slide rules at school to do computations, we only used them to learn how to use slide rules (which was therefore a complete waste of time).

sleepybrett 3y ago

I feel like being gen x i might have been part of the first wave of kids never to learn to use a slide rule. I'm actually not even totally clear on what they are even for. I am really digging some of the other mechanical calculators in the collections though. Always love to see a curta.

BoiledCabbage 3y ago
> I'm actually not even totally clear on what they are even for. The same way you can pick a point on amap, measure a certain distance away on the map and "automatically" know how far away to locations are in really life - you can pick a number on a side rule, move a certain distance away and it will "automatically" multiply or divide two numbers. It will have a small amount of error in it, the same way measuring distance on a map will have a small amount of error in it.

ararar 3y ago

Concise Co. of Japan still makes slide rulers albeit only circular ones (https://www.sliderule.tokyo/products/list.php https://www.sliderule.tokyo/products/list.php). One prominent industry that still uses slide rulers is aviation. They use "flight computers".

twic 3y ago
I suppose pilots often have good eyesight and wear gloves, which makes a slide rule easier to use than a calculator with buttons.

OldGuyInTheClub 3y ago

I've been meaning to dust off my old slide rule for a long time. Learning to use one circa 8th grade made future science so much easier. Had to think of significant figures ahead of time, spend a few moments to plan the computation, and get comfortable with when to approximate and how. Pretty soon I was able to get a sense for what answers ought to be, at least to within a factor of 2-5. Anything outside of that and I knew I'd made a mistake somewhere. I also loved the old HP calculators of the late 1970s to late 1980s and eventually set the slipstick aside but am ever grateful for what it did for me. And for fellow RPNthusiasts, there is the Museum of HP Calculators at https://hpmuseum.org/ https://hpmuseum.org/