Keuffel & Esser 4015 Fuller's Spiral Cylindrical Slide Rule

This rule consists of an outer wooden cylinder that both slides up and down and rotates. Two brass rings lined with felt are inside this cylinder. The cylinder is covered with paper marked with a single spiral logarithmic scale graduated into 7,250 parts and having a length, according to the maker, of 500 inches (nearly 42 feet). This length permitted computations up to four or five significant digits.

Inside the outer cylinder is a longer wooden cylinder, covered with paper marked with decimal, conversion, and sine tables. A solid mahogany handle is at one end. A brass index is screwed to the top of the handle. A second, longer brass index is screwed to the mahogany base and marked with a scale of equal parts used in finding logarithms. A third, removable, nickel-plated brass cylinder is inside the instrument and attached to the base. There is no case.

The tables on the middle cylinder include: decimal equivalents of feet and inches in feet; decimal equivalents of quarter weights and pounds in hundredweights; decimal equivalents of ounces and pounds in fractions of a pound; decimal equivalents of pounds, shillings, and pence in fractions of a pound; decimal equivalents of pence in shillings; days of the year as a fraction of the year; decimal equivalents of subunits of an acre; properties of various metals and woods; decimal equivalents of minutes of a degree in degrees; the Birmingham wire gauge; various conversion factors (mostly for weights and measures); and natural sines.

The outer, sliding cylinder is marked near the top: FULLERS SPIRAL SLIDE RULE. Near the bottom is marked: ENTD. STATS. HALL; STANLEY, Maker, LONDON. The bottom is stamped: 1389. The top of the long brass index is engraved: 1389 (/) 1901. According to Wayne Feely, these numbers indicate the instrument has serial number 1389 and was made by Stanley in 1901. A white celluloid tag affixed to the handle reads: KEUFFEL & ESSER CO. (/) ST. LOUIS. CHICAGO. (/) NEW YORK. (/) U.S.A. In the 1901 Keuffel & Esser catalog, Fuller's Spiral Slide Rule is listed as Model 4015 and priced at $30.00.

See also 311958, 1998.0046.01, and 316575.

References: Wayne E. Feely, "The Fuller Spiral Scale Slide Rule," Chronicle of the Early American Industries Association 50, no. 3 (1997): 93–98; Catalogue of Keuffel & Esser (New York, 1901), 290; James J. Fenton, "Fuller's Calculating Slide-Rule," Transactions and Proceedings of the Royal Society of Victoria 22 (1886): 57–61; Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 42–43; George Fuller, Instructions for the Use of the Fuller Calculator (London: W. F. Stanley & Co., Ltd., [about 1950]), http://www.mccoys-kecatalogs.com/KEManuals/4015/4015.htm. An 1879 first edition of the instructions manual was received with the instrument and is stored in the accession file.

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