Pickett N600-ES Log Log Duplex Slide Rule

This five-inch "eye saver" yellow aluminum linear slide rule has a nylon indicator and is held together with stamped aluminum contoured posts. The front of the base has LL1, A, D, DI, and K scales, with B, ST, T, S, and C scales on the slide. The left end of the slide is marked: MODEL (/) N600-ES (/) LOG LOG (/) SPEED RULE. The right end of the slide bears the form of the Pickett logo that was used between 1958 and 1962. The number 81 is printed above the logo, and MADE IN U.S.A. is printed below it.

The back of the base has LL2, DF, D, and LL3 scales, with CF, Ln, L, CI, and C scales on the front of the slide. The left end of the slide is marked: PICKETT (/) ALL METAL (/) SLIDE RULES. The right end of the slide is marked: PICKETT & ECKEL, (/) INC. (/) CHICAGO, ILL. (/) ©1962. The instrument fits in a red-orange leather case with a clip to slide over a pocket or belt. A leather strip above the clip is stamped in gold with the Pickett triangular logo and PAT. PEND. Raising the strip pulls the rule out of the case.

On January 26, 1959, John W. Pickett applied for a design patent for a slide rule case that resembles the case for this object. The patent was granted on April 5, 1960. It seems likely that the date of this rule is relatively close to the copyright date of 1962. Pickett was the son of company founder Ross C. Pickett and served as president of the firm from 1957 to 1967. For early company history, see 1979.0601.02. The company began manufacturing aluminum slide rules in Alhambra, Calif., in the early 1950s, while retaining offices in Chicago, and changed from glass to nylon indicators in 1958. In 1964, the firm moved to Santa Barbara, Calif., and changed its name from Pickett & Eckel, Inc., to Pickett Industries. In the mid-1970s, Pickett moved to Nogales, Mexico, ceased making slide rules, and was gradually subsumed into Chartpak, Inc., a maker of art supplies and office products now located in Leeds, Mass.

Its compact size and large number of scales made this model popular with engineers who had excellent vision. The Pickett 600-ES was carried on the first five Apollo flights. See the National Air and Space Museum's inventory number A19840160000.

References: John W. Pickett, "Slide Rule Case" (U.S. Patent D187,632 issued April 5, 1960); International Slide Rule Museum, "Pickett All-Metal Slide Rules," http://sliderulemuseum.com/SR_Dates.htm#Pickett; Michael Freudiger, et al., "Mathematics on the Moon: The 'Apollo' Pickett," Journal of the Oughtred Society 10, no. 2 (2001): 15–18; Eric Marcotte, "Pickett Slide Rules," http://www.sliderule.ca/pickett.htm.

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