Jim Frysinger wrote:
>My  guess is that the 1/6 and 1/12 inch divisions are useful for
>page layouts,

O.K., so far.

>figuring 72 picas per inch. If I recall, that makes a 12 point em equal to
>1/6 of an inch.

That's true, but it has nothing to do with this ruler. It's not as
sophisticated as that.

>I'm lost on the 5/32 inch divisions but two things come to mind.
>First, that's darned close to 4 mm! More likely though is that it would
provide
>a leading allowance for 1/8 inch tall (9 point) type.

See previous comment. (By the way, my own thoughts about the 5/32"
graduations are tentative. Joe Reid may remember more about that than I do.)

Bill Potts, CMS
Roseville, CA
http://metric1.org [SI Navigator]



>On Tuesday, 2004 January 13 00:52, Bill Potts wrote:
>> That's a very broad question, because there are so many kinds of rulers.
>>
>> I have a Canadian steel ruler from the early 1970s with two
>scales on each
>> of two sides. On one side, one edge is graduated in 5/32" units, with the
>> other edge in inches, subdivided into 1/6 and 1/12. The inches themselves
>> have two markings -- 1, 2, 3, 4, etc. and 6, 12, 18, 24, etc.
>>
>> On the other side, one edge has inches in 1/10, with each 1/10
>individually
>> marked from 1 to 150. The other edge has inches with 1/4", 1/8",
>1/16" and
>> 1/32" subdivisions. The inches themselves are marked 1, 2, 3, 4, etc. and
>> 150, 300, 450, 600, etc.
>>
>> The ruler has other features I won't mention yet.
>>
>> I want to see who can guess what kind of ruler it is, what some of the
>> numbers mean, and what the other features might be. One clue is that, in
>> spite of having no metric units whatever on it, it is still
>useful and the
>> units (and features) still have a valid purpose.
>>
>> Think "legacy systems."
>> Bill Potts, CMS
>> Roseville, CA
>> http://metric1.org [SI Navigator]
>....
>--
>
>James R. Frysinger
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>Senior Member, IEEE
>
>http://www.cofc.edu/~frysingj
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