I collect rules, but am a rookie at deciphering scales.  This really piqued
my curiosity.  Looking in the Phil Stanley book it mentions a scale AG (Ale
Gallon) which corresponds to the diameter of barrel that will contain one
imperial gallon per inch.  That diameter is 18.95 inches (17.15" for Wine
Gallon).  Could this be some kind of liquid measure scale?  So if the
diameter goes up the depth required goes down.  24 3/4" diameter it only
takes about 3/4" of liquid to equal a gallon.

wild *ss guess,
clint

-----Original Message-----
From: oldtools-bounces@r...
[mailto:oldtools-bounces@r...]On Behalf Of paul womack
Sent: Monday, September 10, 2007 5:08 AM
To: oldtools
Subject: [OldTools] ID: strange scaling ruler

At the weekend I scarfed up an unusual wooden ruler.

It's around 3" wide, and 27" long, and is made
from something like beech (at least it's a light coloured
hardwood, with a fine grain, that isn't box).

It's rather worn.

I bought it because it's some kind of scaling ruler;
it has multiple scales on both faces, with stranges labels.

I will list each "label" and the measured ratio of indicated inches
to actual inches

B18 3/4     1.0
B19 1/2      .96
B20 1/2      .9231
B21          .888
B21 3/4      .8627
B22 1/2      .834
B23 1/4      .808
B24          .7843
B24 3/4      .7582

Those scaling are FAR too big for this to be a pattern makers
shrink rule, and anyway all the shrink rules I've seen are metal.

But the scales aren't extreme enough to be an architects or map makers
scale.

And I don't know any other users of "scaling" rulers...

So what is it?

    BugBear
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