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 slide rule consists of two white celluloid bands, each about one inch wide and twenty inches long, that revolve within an elliptical brown and black Bakelite case. The case has clear plastic windows on both sides. Five green indicator lines appear on each of the windows. The bands are printed with identical logarithmic scales; the left is marked A, and the right is marked B. Two knurled knobs rotate the bands. Large round metal pins inside the knobs can be locked to force the bands to rotate in unison.
- The instrument fits in a brown canvas bag. When it was received, it had a sticker on one side, near the base, that read: PAISLEY (/) MODEL (/) A (/) PITTSBURGH. Both sides near the base read: PAISLEY CALCULATOR. Both sides of the case are marked: PAT.APP.FOR. Both bands are marked: ©1940—PAISLEY CALCULATOR COMPANY, INC. The edge of the A band is also marked: TAPE NO. 3; BASTIAN BROS. CO. ROCHESTER N.Y. Company and union logos appear on either side of the second mark.
- James R. Paisley of Pittsburgh, Pa., copyrighted the A and B scales of the Paisley Calculator on February 23, 1939. The Paisley Calculating [sic] Company of Pittsburgh copyrighted the phrase, "Paisley calculator a whiz at figures," on March 23, 1939. A James R. Paisley died in Pittsburgh on March 2, 1960, while the Social Security Death Index indicates that there was a man named James R. Paisley who lived from 1901 through 1987, dying in Wheeling, W. Va., in 1987.
- No patents associated with Paisley or the Paisley Calculator Company have been located, nor have any advertisements other than a new product notice issued by Office Machines Research, Inc., in 1939. Although this notice indicated the instrument would be made in Carnegie, Pa., presumably Paisley arranged for production with Bastian Brothers of Rochester, N.Y., which has been manufacturing lapel pins, medals, and commemorative items since 1895. The slide rule was expected to sell for $25.00. Since there is so little documentation for the instrument, it likely was produced only for a short time. Thus, this example was probably made near the 1940 copyright date shown on it.
- References: Office Machines Research, Inc., "Preliminary Report on a New Product," American Office Machines Research Service 1 (October 1939): section 4.2; Library of Congress, Catalog of Copyright Entries . . . for the Year 1939 (Washington, D.C.: Government Printing Office, 1940), 410, 633; Wayne Feely, "The Paisley Slide Rule," The Chronicle of the Early American Industry Association 49, no. 4 (1996): 113; Tom and Nancy McAdams, "Woodlawn Cemetery Section 3," Woodlawn Cemetery Association, Pittsburgh, Pa., October 2000, http://freepages.genealogy.rootsweb.ancestry.com/~tandnmca/woodlawn/sec3ntoz.html; "Bastian Company Profile," http://www.bastiancompany.com/about.shtml.
- Currently not on view
- date made
- Bastian Brothers Company
- ID Number
- catalog number
- accession number
- Data Source
- National Museum of American History, Kenneth E. Behring Center