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what is an inch?

March 2, 2009

Which one of these rulers do you like better? Why?

(Both rulers are accurate: apparent difference between them is caused by parallax error of camera position.  They are both made by the Lufkin company of Saginaw, Mich.)

Update: see comments

Categories: Uncategorized
  1. Ray
    March 2, 2009 at 05:51 | #1

    Interesting? Not overly.

    Like better? Well, the lower one, of course – it’s obvious!

    Seriously, though, if I needed to measure and mark a particular length, it is (for me, anyway) much easier to do so above the rule line rather than below it. Of course, one could turn #1 upside down to achieve the same effect, but then one would be prone to needless errors due to the inversion.

  2. gruntled atheist
    March 2, 2009 at 12:23 | #2

    What Ray said.

  3. March 2, 2009 at 12:49 | #3

    Here’s what I thought was interesting (not fascinating, but a bit o’ tech history) about them.  The aluminum ruler 60 is years older than the wooden one, and probably cost an arm and a leg when it was made.  The numbers and lines appear to be machine-turned; that’s one hell of a lot of machine-turning on both sides of a 6-foot folding rule.

    The wooden ruler raises other questions.  How the hell did they print – in paint – on wood so accurately?  Both rulers check out perfectly against a Starrett calibration rule.

    Then there’s the matter of style. The numbers on the newer ruler abandon the turned style (older wooden rulers had machine-turned style, even though they were stamped).  They are certainly readable, but IMHO less attractive.

    And yes, at some point, someone said; “Why not have markings on both edges of the rule?”  It’s not like anything new had to be invented for that change.  Why was this idea obvious in 1980 but not in 1920?  What triggers innovation?

  4. March 2, 2009 at 17:10 | #4

    I’ve been pondering this all day, and I just can’t work up an emotional response to this ruler issue.

  5. March 2, 2009 at 21:18 | #5


    Sorry to get all persnickety, but when I hear that, I think of a finish like this:


    nowadays made with a drill press and a wire brush with lapping compound, it’s great for a low-friction metal to metal contact like inside of watch movements. It’s also a decorative finish.

    I don’t know the proper term to use here though. Maybe engraved?

    anyway, I like the metal ruler, although I thought it was made of steel. They don’t make ‘em like they use to,

  6. March 2, 2009 at 21:31 | #6

    I’d be more likely to collect and keep and show off the upper one—but more likely to use the bottom one.

  7. March 2, 2009 at 22:45 | #7

    Sorry, Gerry; sometimes I just geek on technology history.  I’d like to have been a fly on the wall the first time someone said; “Hey!  Let’s put markings on both edges!”  Did anyone argue against the idea?  And with all the care lavished on the first ruler, why didn’t they think of it earlier?

    Standard Mischief: whoops, I used the wrong term.  A correct term is “machine divided” or “engine divided” using a device invented for making absolutely regular engravings. It played a huge role in the industrial revolution. Clever machine, and an early example of open-source design (at least the one whose development was funded by the Board Of Longitude). 

    I guess engine dividing is pretty automated but the amazing thing is that the ruler consists of 12 folding pieces, and yet it’s as accurate as a good tape measure.  The brass joints are damned clever – same design on both rulers.

    ***Dave, yep; I use the wooden ruler, have a couple of them.  The aluminum one I keep in a box with nifty old tools.  The wood one is not as pretty but is easier to use for reasons mentioned.

    I found the aluminum one in an alley behind a bar.

  8. March 3, 2009 at 19:56 | #8

    I sure like the typeface on the top one.  The top one is an RF, the bottom a DSLR.

  9. March 4, 2009 at 22:14 | #9

    I would prefer the bottom one too. I hated using rulers in school with markings on only one side! What a pain.

  10. March 5, 2009 at 12:03 | #10

    The top one has better marketing :-)
    Should it ever be (partially) damaged you would immediately know where to buy a new one, and even which part number to order.

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