A. W. Faber Mannheim Simplex Slide Rule

This one-sided, ten-inch wooden rule has a layer of white celluloid on the front side. It has unlettered A and D scales on the base and B and C scales on one side of the slide. The other side of the slide has lettered S, L, and T scales. The bottom left corner is marked: QUOTIENT (/) +1. The bottom right corner is marked: PRODUCT (/) –1. The indicator is glass in a metal frame, with a circular scale and pointer on the right side of the frame for registering digits to be added or subtracted during the calculation. The top edge is beveled and has a 25-centimeter scale, divided to millimeters. A second scale, 27 centimeters in length, is on the front edge. Underneath the slide is a third centimeter scale, numbered from 30 to 55.

The bottom of the base is marked in gold: A. W. FABER. D.R.G.M. 98350 & 116832. A set of tables of equivalent measures printed in German on paper is glued to the back of the instrument. The rule is in a cardboard case covered with black leather. The case is marked: Rechenstab (/) von (/) A. W. Faber. Inside the case is written in pencil: Mit Anlistz (/) [illegible] 10 (/) R. C. Archibald. On the back of the inside is written in pencil: RCA.

A. W. Faber was a German company that began manufacturing slide rules in 1882 and introduced this form of instrument around 1894. German patent 116832 was issued to A. W. Faber in June 1899. The digit-registering cursor was added in 1905. Although there is no model number on this rule, it was sold as model 367 from 1905 to 1913. The firm was renamed Faber-Castell in 1905, although instruments continued to be marked "A. W. Faber" as late as 1913.

This slide rule reflects the rich intermixture of cultures that characterizes the American mathematical community. It was owned by Raymond C. Archibald (1875–1955), a Canadian born in Nova Scotia. He began his college education in Canada and completed a bachelor's and a master's degree from Harvard University in Cambridge, Mass. Then, like several other late 19th- and early 20th-century North American mathematicians, Archibald traveled to Germany, spending the academic year 1898–1899 at the University of Berlin and 1899–1900 at the University of Strasbourg. He obtained his Ph.D. in Strasbourg in 1900 and may have purchased this slide rule near the end of this European sojourn. Archibald then returned to Canada, where he taught for several years before joining the faculty of Brown University in Providence, R.I., in 1908. He remained at Brown for the rest of his academic career. Archibald's wide ranging interests included the history of mathematics, the computation of mathematical tables and the development of computing tools. In 1943, he became the founding editor of the journal Mathematical Tables and Other Aids to Computation, a publication that included some of the first articles published about electronic computers.

References: Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 25–26, 41; Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 24; George Sarton, "Raymond Clare Archibald," Osiris 12 (1956): 4–34; Charles N. Pickworth, Instructions for the Use of A. W. Faber's Improved Calculating Rule (New York: A. W. Faber, [after 1900]), 36–40. This work is undated, but it refers to a prize awarded to Faber at the Exposition universelle held in Paris in 1900. The pages cited describe "a new form of A. W. Faber's calculating rule," the form of the slide rule catalogued here.

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