4.13 Sterling, Acu-Rule, Festus, USA

Festus Manufacturing made slide rules beginning in 1938 in Festus, Missouri, USA. The company was renamed Acu-Rule Mfg. Co. in 1939 and produced slide rules branded as Acu-Rule and Acu-Math. The company later relocated to St. Louis, Missouri and then to Mt. Olive, Illinois in 1954. Eventually Acu-Math became the standard brand for the Acu-Rule Mfg. Co.

Sterling Plastics made slide rules in Mountainside, New Jersey, from about 1961-1972, and were another manufacturer of rules often used by students. Several of those shown in the collection are mine from my high school years in the 1970’s. In 1969 Sterling Plastics merged with Acu-Rule, and Acu-Math became the standard brand of the Acu-Math Division of Sterling. Sterling was subsequently purchased and became a division of Borden Chemical Co. in 1970. Slide rules were produced by Borden until 1972.

Festus 50. Festus, MO

Festus Acu-Rule 10D.

Acu-Rule Acu-Math 90A. St. Louis, MO

Acu-Rule Acu-Math 1300 (Government Issued). Mt. Olive, IL

Sterling 594.

Total number of Festus, Acu-Rule and Sterling slide rules in the collection: 9.

Maker Model Year Mat Size Case Note
Festus 50 1938 wd 10 no Festus Model 50; rough condition; magnifier cursor
Festus Acu-Rule 10D 1938 wd 10 box Nice early rule; paper scales on wood; good condition; magnifier cursor
Acu-Rule Acu-Math 90A
1945 Mg 10 yes St. Louis, Mo., USA; Mannheim Trig; dimpled slide; special leather case; Acu Design pat. pending; owner R.W. Shutt, Tower City, Pa.
Acu-Rule Acu-Math 1300
1965 pl 10 yes Log Log Decimal Trig; U.S. Government No. GA 7520-551-5227; Instructions for using Trig and Log Log Slide Rules
Sterling 684
1968 pl 10 no beginner’s slide rule; instruction sheet
Sterling 587
1970 pl 5 no pocket rule
Sterling 587 1972 pl 5 no pocket rule; from my high school years (Soph year, 1972)
Sterling 594 1972 pl 10 yes Decimal Trig Log-Log; from my high school years (Jr year, 1973)
Sterling 594 1972 pl 10 yes Decimal Trig Log-Log; duplicate of my high school rule