Acu-Math 130 Duplex Slide Rule

This ten-inch duplex linear magnesium slide rule is coated with layers of white vinyl and has finger holes at both ends of both sides of the slide. On the front, the base has L, LL1, DF, D, LL3, and LL2 scales, with CF, CIF, CI, and C scales on the slide. The top of the base is marked LOG LOG DECIMAL TRIG ACU-MATH No 130 MADE IN U S A. On the back, the base has LLO, LLOO, A, D, S, ST, and T scales, with B, K, CI, and C scales on the slide. The indicator is plastic with white plastic edges. A maroon leather case with belt loop has a window marked: F. G. VIANZON.

The Acu-Rule Manufacturing Company was founded in 1938 in Festus, Mo., as the Festus Manufacturing Company. Renamed Acu-Rule Manufacturing Company in 1940, it soon was moved to St. Louis. In 1950 the company adopted the brand name Acu-Math (or ACUMATH). The firm moved to Mt. Olive, Ill., in 1954 and was sold to Sterling Plastics of Mountainside, N.J., in 1968. This model was not among the first rules sold by the firm, nor is it listed in a 1960 company catalog. Hence, it appears to date between 1950 and 1959. The donor's father, Felipe G. Vianzon, used this instrument.

Reference: George E. Keane, "A History of the Festus Manufacturing Company and Its Successor, the Acu-Rule Manufacturing Company, Makers of the Acu-Rule and ACUMATH Slide Rule," Journal of the Oughtred Society 14, no. 1 (2005): 51–54.

Currently not on view