Keuffel & Esser 68-1944 Demonstration Slide Rule

In the early twentieth century, a growing proportion of American children attended public schools. However, some continued to prefer private academies. For example, the Thurston Prep School, founded in Shadyside, Pennsylvania, in 1887, was devoted to teacher training for young women. A similar school in Shadyside – which also had young boys as students – was established in 1902 and soon named the Winchester School. Financial difficulties at the time of the Depression led to a merger of the two schools in 1935 – male students were then limited to kindergarten and first grade, and the curriculum resembled public elementary schools and high schools. Winchester Thurston moved to new premises in 1967, and at about that time purchased this teaching slide rule. The instrument was donated to the Smithsonian by the school through the good offices of Frances Glockler Hein (1923-2012). Mrs. Hein, as she was known to students, was born in California, raised in Minneapolis, and attended the University of Iowa. In late 1943 she graduated from iowa with a B.A. in mathematics. The next year she married a slightly older University of Iowa student, Richard E. Hein, who then was studying chemistry at Iowa State University and working on the Manhattan Project. They soon had four sons. By 1964, the boys were sufficiently grown for her to take a position at Winchester Thurston, where she taught mathematics for over twenty years.

In 1967, Winchester Thurston moved to a new campus. At about that time, the school acquired this 79-inch demonstration slide rule. It is made of painted wood, with a plastic cursor that has a wooden frame. In the early seventeenth century, the Scottish mathematician John Napier had discovered functions known as logarithms which make it possible to reduce problems of multiplication, division, and taking the roots of numbers to additions and subtractions. On a slide rule, the logarithms of numbers are represented as lengths. To multiply, one length is set on the base, and another added to it using the slide. The sum of the logarithms, which gives the product, is read off using the cursor. This slide rule also has scales for finding the squares, cubes, square roots, and cube roots of numbers.

Slide rules had first became popular in the United States in the 1890s, especially among engineers and scientists. Use of the device was taught in high schools and universities using oversized instruments like this. During the 1960s, the United States placed new emphasis on teaching mathematics and science. By the late 1970s, slide rules would be almost entirely displaced by handheld electronic calculators.

References:

Yearbooks and student newspapers of the University of Iowa.

Registrar's Office, University of Iowa.

Online obituary of Frances G. Hein at tributes.com.

Winchester Thurston School, Thistle Talk Commemorative Edition, vol. 39 #1, Summer, 2010.

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