3 ms·

Mine had them. I don't think that I'd prefer it for accounting work, though.

by zeveb 8y ago

lisper 8y ago
> Mine had them. I doubt that very much. Do you have a photograph? I used to collect slide rules. I have never seen one with a linear scale, and I can't find any evidence on the web that any such slide rule was ever manufactured. So if you can provide evidence that you possessed such a slide rule, that would be of significant historical interest.
- kens 8y ago
  Isn't the "L" scale on a slide rule linear? See the photo at the top of the Wikipedia page [1] for example. (I may be confused here, since you know slide rules better than me.) [1] https://en.wikipedia.org/wiki/Slide_rule https://en.wikipedia.org/wiki/Slide_rule
  - ghaff 8y ago
    Yes, but I'm not sure you could easily use them for addition. They exist to lookup the value of various logarithms. Adding's pretty fast anyway.
  - lisper 8y ago
    Sure, but to do addition you need two linear scales, one on the fixed part and one on the slider. The L scale is for computing logarithms, not for doing additions.
    - Someone 8y ago
      If the L scale is on the slider, and you’re not too much concerned accuracy (the procedure does 5 ‘align scales’ operations before the final ‘read the result’) one linear scale is sufficient, if you use the hairline on the cursor as a kind of memory: ”Example: calculate 0.23 + 0.45 - "Reset" the rule so that all the scales are lined up. - Move the cursor to 0.23 on the L scale. - Move the leftmost 0 on the L scale to the hairline. - Move the cursor to 0.45 on the L scale. - Reset the rule again so that all the scales are lined up. - The cursor should now be at 0.68 on the L scale, which is the sum of 0.23 + 0.45.” (from http://www.antiquark.com/2005/01/slide-rule-tricks.html http://www.antiquark.com/2005/01/slide-rule-tricks.html)
      - lisper 8y ago
        Another possibility: Using a sledge hammer, break the slide rule into N pieces, taking care to insure that N is greater than the sum you wish to compute. Now to compute the sum of A and B, count out A pieces into a paper bag, then count out B pieces into the same paper bag. Now empty the bag onto a clean workspace and count the total number of pieces to produce the result. https://www.mrao.cam.ac.uk/~steve/astrophysics/webpages/barometer_story.htm https://www.mrao.cam.ac.uk/~steve/astrophysics/webpages/baro...
- zeveb 8y ago
  I checked, and sure enough you're correct. I could have sworn that I'd had two linear scales, but … I was completely wrong. Been decades since I used it, and the memories obviously faded.
  - lisper 8y ago
    No worries, happens to everyone. But I appreciate you confirming that.

Mine had them. I don't think that I'd prefer it for accounting work, though.

by zeveb 8y ago

Mine had them. I don't think that I'd prefer it for accounting work, though.

> Mine had them. I doubt that very much. Do you have a photograph? I used to collect slide rules. I have never seen one with a linear scale, and I can't find any evidence on the web that any such slide rule was ever manufactured. So if you can provide evidence that you possessed such a slide rule, that would be of significant historical interest.

kens 8y ago
Isn't the "L" scale on a slide rule linear? See the photo at the top of the Wikipedia page [1] for example. (I may be confused here, since you know slide rules better than me.) [1] https://en.wikipedia.org/wiki/Slide_rule https://en.wikipedia.org/wiki/Slide_rule
- ghaff 8y ago
  Yes, but I'm not sure you could easily use them for addition. They exist to lookup the value of various logarithms. Adding's pretty fast anyway.
- lisper 8y ago
  Sure, but to do addition you need two linear scales, one on the fixed part and one on the slider. The L scale is for computing logarithms, not for doing additions.
  - Someone 8y ago
    If the L scale is on the slider, and you’re not too much concerned accuracy (the procedure does 5 ‘align scales’ operations before the final ‘read the result’) one linear scale is sufficient, if you use the hairline on the cursor as a kind of memory: ”Example: calculate 0.23 + 0.45 - "Reset" the rule so that all the scales are lined up. - Move the cursor to 0.23 on the L scale. - Move the leftmost 0 on the L scale to the hairline. - Move the cursor to 0.45 on the L scale. - Reset the rule again so that all the scales are lined up. - The cursor should now be at 0.68 on the L scale, which is the sum of 0.23 + 0.45.” (from http://www.antiquark.com/2005/01/slide-rule-tricks.html http://www.antiquark.com/2005/01/slide-rule-tricks.html)
    - lisper 8y ago
      Another possibility: Using a sledge hammer, break the slide rule into N pieces, taking care to insure that N is greater than the sum you wish to compute. Now to compute the sum of A and B, count out A pieces into a paper bag, then count out B pieces into the same paper bag. Now empty the bag onto a clean workspace and count the total number of pieces to produce the result. https://www.mrao.cam.ac.uk/~steve/astrophysics/webpages/barometer_story.htm https://www.mrao.cam.ac.uk/~steve/astrophysics/webpages/baro...
zeveb 8y ago
I checked, and sure enough you're correct. I could have sworn that I'd had two linear scales, but … I was completely wrong. Been decades since I used it, and the memories obviously faded.
- lisper 8y ago
  No worries, happens to everyone. But I appreciate you confirming that.