Pickett N4-ES Vector-Type Log Log Duplex Slide Rule

This aluminum ten-inch linear duplex slide rule is coated in Pickett's "Eye Saver" yellow plastic. The flat nylon indicator is screwed within a white plastic frame. The front top of the base has three extended cube root scales (one for numbers with 1, 4, 7, 10, or more digits before the decimal point; one for numbers with 2, 5, 8, 11, or more digits; and one for numbers with 3, 6, 9, 12, or more digits) and a DF scale. The front bottom of the base has D, DI, and square root scales. The top square root scale gives roots of numbers on the D scale with an odd number of digits before the decimal point; the lower square root scale gives roots of numbers with an even number of digits. The front of the slide has CF, CIF, double T, ST, S, CI, and C scales.

The left end of the slide is marked: MODEL N4-ES (/) Vector-Type LOG LOG (/) DUAL-BASE SPEED RULE. The right end has "Pickett" in script on a triangle with a dot at one point. MADE IN U.S.A. appears beneath the logo. This form of logo was in use from 1958 to 1962. The style of the grooved stamped aluminum posts is also consisted with this timeframe.

The top back of the base has LL1, LL2, and DF/M scales. D, LL3, and LL4 scales are on the bottom of the base. The back of the slide has CF/M, TH, SH, Ln, L, CI, and C scales. The back of the slide is marked at the left end: COPYRIGHT 1959© (/) PATENT APPLIED FOR. The right end is marked: PICKETT (/) ALL METAL (/) SLIDE RULES (/) PICKETT & ECKEL INC. (/) CHICAGO ILL. U.S.A. The mention on the instrument of a patent application may refer to a patent for a case issued to John W. Pickett in 1960. Pickett was the son of company founder Ross C. Pickett and served as president of the firm from 1957 to 1967.

The slide rule is in a red-brown leather case lined in white plastic. The triangular Pickett logo is stamped in gold on the front of the case, and a metal ring on the back is for a leather strap (no longer with the instrument) that can be hung around a belt loop. See 1980.0097.04 for instructions.

The donor, engineer Edgar F. Peebles, obtained this slide rule free of charge as a replacement when the numbers came off the slide rule he had used in college. He first used it from 1959 to 1965 in the satellite control facility of the Air Force at Sunnyvale, Calif. He then used it as a down range representative for Lockheed Missiles and Space Company from 1965 to 1968 in tests of the Polaris missile. Finally, from 1968 to 1969 he used the slide rule in the checkout area of the test Polaris missile manufacturing plant in Sunnydale.

References: Rodger Shepherd, "Pickett's 'Eye Saver Yellow,'" Journal of the Oughtred Society 1, no. 1 (1992): 18; International Slide Rule Museum, "Pickett All-Metal Slide Rules," http://sliderulemuseum.com/SR_Dates.htm#Pickett; Maurice L. Hartung, How to Use . . . Pickett Dual Base Log Log Slide Rules (Chicago: Pickett & Eckel, Inc., 1953), http://sliderulemuseum.com/Manuals/M103_Pickett_HowToUseDualBase_1953.pdf; John W. Pickett, "Slide Rule Case" (U.S. Patent D187,632 issued April 5, 1960); accession file.

Currently not on view