Slide RulesCylindrical Slide Rules
Writing a logarithmic scale in a spiral that is then imprinted around the outside of a cylinder allows instrument makers to lengthen the scale. Since a logarithmic scale only needs to run to 10 twice to include all possible results from adding or subtracting two logarithmic numbers, this means that the distance between the points on the scale may be increased. When any two numbers on the scale are further apart, the user may read a fractional position between these numbers (expressed as a decimal) to a finer level of granularity. For example, on a 10" linear slide rule, results generally may be calculated to only three significant figures (0.123, 1.23, 12.3, 123, 1230, and so on). A cylindrical slide rule may provide results of up to seven significant digits (0.1234567, 1.234567, 12.34567, 123.4567, 1234.567, and so on).
On the other hand, cylindrical slide rules were typically about twice as expensive to produce as linear slide rules, and the provenances for the objects on this page indeed suggest that, in the main, only corporate and government offices could afford them. A number of the objects in this category were received with instruction manuals and advertising pamphlets, which may be viewed in the Index by Makers & Retailers. The collection includes multiple examples for several of the objects, as the 23 items below represent only eight different slide rules, half developed in Europe and half invented by Americans. The cylindrical slide rule by Edwin Thacher, a Pennsylvania railroad bridge designer, also illustrates the 19th-century shift in production from Europe to the United States, as originally William Ford Stanley's London firm made the entire instrument. Then, Keuffel and Esser of New York City began constructing the wooden drum and brass and wood stand while continuing to import the scales printed on paper and pasted around the drum. Finally, K&E developed its own dividing engine for printing the scales and henceforth manufactured the entire instrument in the United States.
"Slide Rules - Cylindrical Slide Rules" showing 1 items.
- This large cylindrical slide rule consists of an aluminum frame supporting a horizontal rotating aluminum drum. Paper covering the drum is marked with 60 logarithmic C and D scales that are 20.5" long and run from 1,000 to 10,000. Each scale repeats part of the previous scale, so the instrument is approximately equivalent to a linear slide rule 50 feet (or 15m) long. A slotted cylindrical sleeve that is 13" long fits over the drum. It slides back and forth. The right end of the sleeve is secured in an aluminum ring. The ring and sleeve can rotate independently of each other.
- The sleeve's 60 slats are marked with logarithmic scales that run from 100 to 1,000. Four small clear celluloid triangles attached to the slats serve as indicators. Black bands on either side of the drum and on the left side of the sleeve are marked with numbers from 1,000 to 9,623. The bands on the sleeve were originally covered with clear celluloid.
- The side pieces of the frame are both marked: LOGA. The ends of the drum are both marked: LOGA-CALCULATOR • ZURICH. The band on the right side of the sleeve is marked: Loga - Calculator 15m Patente Daemen Schmid, Uster - Zürich.
- The Swiss firm of Heinrich Daemen-Schmid manufactured approximately 30,000 cylindrical Loga-Calculators between 1900 and 1935. Daemen-Schmid patented the device in the United States in 1912. The donor, Jacques Kayalaff (1898–1983), was an international banker who used this instrument for calculations relating to currency exchange. He purchased it around 1925 for $500.
- References: Accession File; Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 42, 44; Heinrich Daemen-Schmid, "Computing Device" (U.S. Patent 1,036,575 issued August 27, 1912); Heinz Joss, "350 Jahre Rechenschieber, und was die Region Zürich dazu beigetragen hat (350 Years of Slide Rules, and What the Zurich Region Has Contributed)," Vierteljahreszeitschrift der Naturforschenden Gesellschaft in Zürich 146, no. 2–3 (2001): 75–82, http://www.rechenschieber.org/zurich.html.
- Currently not on view
- date made
- ca 1925
- ID Number
- catalog number
- accession number
- Data Source
- National Museum of American History, Kenneth E. Behring Center