A  History of the Festus Mfg. Co.
and its successor
The Acu-Rule Mfg. Co.

Makers of the ACU-RULE and ACUMATH Brand Slide Rule
also information about
The Slide Rule and Scale Engineering Co.

Copyright George E.  Keane November 30,  2004
Festus, Missouri.

This is a redesigned version updated and published November 24, 2006

Copyright November 24, 2006

This slide rule is a near mint example of a model 10J.  These slide rules had the numerical scales printed on paper that w
as then glued to the wood body.  The wood was milled so that a raised shoulder would prevent wear on the paper.  This model had a flat, 1/8 inch beveled edge, red line  Lucite cursor. This and three other models were the first  production models made in Festus, Missouri.  The price for this slide rule was $18.00 per gross or twelve and a half cents.

Above is a 1938 model 50 with paper scales.
Note that the "A" scale has been lost. This
model has a 10 inch ruler and a metric ruler
on the edges

This material is in book form in the reference section of the Festus, Missouri library and the Abraham Lincoln Presidential Library, Springfield, Illinois.  About 95 pages of detailed business records, additional pictures, newspaper clippings and other items of documentation are in the book plus the text from the first version of this web page.

This web page is the result of three years research and many revisions.