Science & Mathematics

Chemical Balance

The Museum's collections hold thousands of objects related to chemistry, biology, physics, astronomy, and other sciences. Instruments range from early American telescopes to lasers. Rare glassware and other artifacts from the laboratory of Joseph Priestley, the discoverer of oxygen, are among the scientific treasures here. A Gilbert chemistry set of about 1937 and other objects testify to the pleasures of amateur science. Artifacts also help illuminate the social and political history of biology and the roles of women and minorities in science.

The mathematics collection holds artifacts from slide rules and flash cards to code-breaking equipment. More than 1,000 models demonstrate some of the problems and principles of mathematics, and 80 abstract paintings by illustrator and cartoonist Crockett Johnson show his visual interpretations of mathematical theorems.

Topic: Slide Rules

Lawrence Engineering Service 10-B Mannheim Simplex Slide Rule

This inexpensive 9-1/2 inch one-sided wooden slide rule is painted white on the front face. A, D, and K scales are on the base, and B, CI, and C scales are on one side of the slide. A plastic indicator is in a metal frame. The top of the base is marked: MADE IN U.S.A.
Description
This inexpensive 9-1/2 inch one-sided wooden slide rule is painted white on the front face. A, D, and K scales are on the base, and B, CI, and C scales are on one side of the slide. A plastic indicator is in a metal frame. The top of the base is marked: MADE IN U.S.A. It is also marked LAWRENCE ENGINEERING SERVICE, PERU, INDIANA and PAT. PEND. The right end of the slide is marked: 10-B. Tables for equivalents and conversions appear on the back of the instrument, which is in a cardboard box covered with black synthetic leather.
George Lee Lawrence (1901–1976) established a firm in Chicago to make slide rules for photography. In 1935 he moved to Wabash, Ind., renamed the company Lawrence Engineering Service, and began to manufacture general purpose slide rules. In 1938 he relocated once more to Peru, Ind., probably to enlarge the factory. Lawrence's second wife, Vivian Breyer, received the company in their 1947 divorce. Its name was changed to Engineering Instruments, Inc., and the company remained in business until its building burned down in 1967. Thus, this rule dates between 1938 and 1947. The model 10-B sold for 25 cents during this period. There is no record that Lawrence ever received a patent for any aspect of his design or manufacturing process. According to the donor, this rule belonged to her father, George L. Sterns. Compare to 1980.0097.02.
References: Bruce Babcock, "Lawrence Engineering Service — A Tale from an American Small Town," Journal of the Oughtred Society 5, no. 2 (1996): 55–61; David G. Rance, "The Unique Lawrence," Proceedings of the 17th International Meeting of Slide Rule Collectors (September 2011), 87–107, http://www.sliderules.nl/index.php?p=papers; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 195–196; accession file.
Location
Currently not on view
date made
1938-1947
maker
Lawrence Engineering Service
ID Number
1983.0042.01
accession number
1983.0042
catalog number
1983.0042.01

Knox Hydraulic Pump Slide Rule

This rule consists of a clear plastic envelope, glued together along the back bottom edge, and a white plastic slide. The front is marked: KNOX (/) SO. WALPOLE/W. SPRINGFIELD. MASS./BRIDGEPORT, CONN. (/) PNEUMATIC & (/) HYDRAULIC SYSTEMS & (/) COMPONENTS.
Description
This rule consists of a clear plastic envelope, glued together along the back bottom edge, and a white plastic slide. The front is marked: KNOX (/) SO. WALPOLE/W. SPRINGFIELD. MASS./BRIDGEPORT, CONN. (/) PNEUMATIC & (/) HYDRAULIC SYSTEMS & (/) COMPONENTS. By setting the force in pounds opposite the PSI of a line, a user can read the diameter of a cylinder in inches. By setting the rule to the desired diameter of a cylinder, the user reads the displacement in cubic inches opposite the length of a stroke in inches. By setting the back of the rule to a desired pump delivery in gallons per minute, the user reads the time in seconds opposite displacement in cubic inches and the velocity of oil flowing through the pipe (in feet per second) opposite the area of the pipe in square inches.
Knox, Inc., manufactured hydraulic pumps. From its headquarters on Foxhill Drive in South Walpole, Mass., the company filed for trademarks in 1966 and 1968 and was assigned U.S. Patent 3,599,849 in 1971. Thus, this rule likely dates to around 1970. By 1980, the company was renamed Knox-Norton, Inc., and headquartered in Hartford, Conn.
Reference: U.S. Patent and Trademark Office, Trademark Electronic Search System.
Location
Currently not on view
date made
ca 1970
maker
Knox, Inc.
ID Number
1988.0795.02
accession number
1988.0795
catalog number
1988.0795.02

Controller Circular Slide Rule for Canadair

This aluminum circular slide rule has a D scale on the base and C, CI, and A scales on the rotating disc. (These scales are not marked with letters.) Parts of the D and C scales are shaded in blue and yellow, and the CI scale is printed in red.
Description
This aluminum circular slide rule has a D scale on the base and C, CI, and A scales on the rotating disc. (These scales are not marked with letters.) Parts of the D and C scales are shaded in blue and yellow, and the CI scale is printed in red. A clear plastic rotating indicator is fastened with an aluminum screw and nut. The center of the rotating disc is marked: CONTROLLER, and a black arrow indicates the origin point.
The back of the instrument has a ruler around the serrated edge, marked by single centimeters from 0 to 20. Between the numbers 0 and 20 is marked DBGM, which stands for "Deutsches Bundes Gebrauchsmuster," or German Federal Registered Design. This indicates the device was made in West Germany after 1949. Inside the ruler is a chart shaped like a wheel, for making conversions between various weights and measures. The center is marked: MADE IN GERMANY (/) © (/) CONTROLLER (/) MÜNCHEN 15. Controller manufactured a few types of circular slide rules in Munich in the second half of the 20th century. This instrument most closely resembles Controller's model Mod 75 R.
The slide rule fits in a round, dark blue plastic sleeve. The sleeve is marked: C-L (/) CANADAIR LIMITED. The instrument was probably distributed as a promotional item by Canadair, an aircraft manufacturer established in 1944 that was the Canadian subsidiary of General Dynamics from 1954 to 1976, when it was nationalized. The company was acquired by Bombardier Inc. in 1986. The slide rule was probably made around 1960.
References: Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 154; "Herman van Herwijnen's Slide Rule Catalogue at ISRM – C," http://sliderulemuseum.com/HSRC/SRC_C.htm; James Marsh, "Canadair Ltd.," The Canadian Encyclopedia, http://thecanadianencyclopedia.com/articles/canadair-ltd.
Location
Currently not on view
date made
ca 1960
maker
Controller
ID Number
1985.0788.01
accession number
1985.0788
catalog number
1985.0788.01

Keuffel & Esser 4092-3 Log Log Duplex Slide Rule

This ten-inch mahogany two-sided linear slide rule is coated with white celluloid and held together with L-shaped metal end pieces. On one side, the base has K, DF, D, and L scales, with CF, CIF, CI, and C scales on the slide.
Description
This ten-inch mahogany two-sided linear slide rule is coated with white celluloid and held together with L-shaped metal end pieces. On one side, the base has K, DF, D, and L scales, with CF, CIF, CI, and C scales on the slide. The right end of the slide is marked in red: < 4092-3 >. The bottom of the base is marked in red: KEUFFEL & ESSER CO. N.Y.; PAT. JUNE 5. '00 DEC. 22. '08 APRIL 1 '24; MADE IN U.S.A. On the other side, the base has LL0, A, LL3, LL2, and LL1 scales, with B, S, T, and C scales on the slide. The left end of the slide and the front of the base are marked with a serial number: 373480.
The indicator is frameless glass with plastic edges held together with metal screws. One edge is marked: K&E.CO.N.Y. (/) PAT.8.17.15. The rule fits in a brown leather case, which is marked on the front of the flap: 4092-3S. The top of the flap is marked: K & E (/) LOG LOG DUPLEX (/) SLIDE RULE. The names of several former owners of the rule are written on the case, including: Bill A.'s; Charles Potter; Theta Xi; Wm. Lund (/) 407 Delaware (/) Ave. (/) Bethlehem Penn.
For information on the patents, see 322761, 318475, and 318479. Keuffel & Esser of New York introduced model 4092-3 in 1922 and in 1925 added a K scale to the rule and an N to the prefix of the model number. The prefix was dropped in 1936, but the indicator was replaced with a new version of K&E's frameless indicator. K&E stopped selling model 4092-3 in 1938, when it was priced with a leather case at $11.75. The serial number on this example is consistent with a manufacture date between 1936 and 1938, but the indicator is of the pre-1936 style. Compare to 1981.0933.01.
References: K&E Slide Rules and Calculating Instruments (New York, 1922), 10–11; K&E Slide Rules and Calculating Instruments (New York, 1925), 10–11; Catalogue of Keuffel & Esser Co., 38th ed. (New York, 1936), 318–319; Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg.
Location
Currently not on view
date made
ca 1936
maker
Keuffel & Esser Co.
ID Number
1984.1068.02
catalog number
1984.1068.02
accession number
1984.1068

Darling, Brown & Sharpe Astronomical Linear Slide Rule

This large mahogany linear astronomical slide rule is covered with strips of German silver. There are two slides, each of which have scales on both sides. Each slide has a knob near one end for moving it; these may be unscrewed and attached on the reverse side.
Description
This large mahogany linear astronomical slide rule is covered with strips of German silver. There are two slides, each of which have scales on both sides. Each slide has a knob near one end for moving it; these may be unscrewed and attached on the reverse side. One slide is marked COLLIMATION on one side and AZIMUTH on the other. The other slide is marked LEVEL AZIMUTH on one side and REFRACTION on the other. The base has four identical, unlabeled logarithmic scales, each of which runs from 1 to 10 twice (with a bit more at each end).
On the center portion of the base, the instrument is marked Darling Brown & Sharpe Providence R.I. Darling, Brown & Sharpe did business under that name from 1866 to 1892. For additional company history, see 1977.0460.01. According to records of the United States Naval Observatory, this slide rule was purchased for $154.00 in December 1887. Few slide rules specifically for astronomy survive, so these large and expensive objects were probably not widely used. Compare to two late 19th-century rules held by the Powerhouse Museum, http://www.powerhousemuseum.com/collection/database/?irn=233017.
Reference: Ledger of Instruments Purchased by the U.S. Naval Observatory, ca. 1845–1906, United States Naval Observatory, Washington, D.C.
Location
Currently not on view
date made
1887
patentee
Darling, Samuel
maker
Brown & Sharpe Manufacturing Company
ID Number
1987.0693.01
catalog number
328994
accession number
1987.0693

Dietzgen 1732 Decimal Trig Log Log Duplex Slide Rule

This ten-inch, two-sided wooden slide rule is coated with white plastic and has a glass indicator with plastic and metal edges. The endpieces are L-shaped metal. The front of the base has L, LL1, DF, D, LL3, and LL2 scales, with CF, CIF, CI, and C scales on the slide.
Description
This ten-inch, two-sided wooden slide rule is coated with white plastic and has a glass indicator with plastic and metal edges. The endpieces are L-shaped metal. The front of the base has L, LL1, DF, D, LL3, and LL2 scales, with CF, CIF, CI, and C scales on the slide. The top of the base is marked: DIETZGEN MANIPHASE MULTIPLEX DECIMAL TRIG TYPE LOG LOG RULE CAT. NO. 1732. The back of the base has LL0, LL00, A, D, DI, and K scales, with B, T, ST, and S scales on the slide. The top of the base is marked: EUGENE DIETZGEN CO. PATS. 2,170,144 2,285,722 MADE IN U.S.A. 530361. The case is cardboard covered with black leather. A Dietzgen logo is on the flap—the letter D inside the letter E inside the letters Co. Paper taped to the case is marked: PHILIP KRUPEN.
Model 1732 does not appear on a 1943 price list for the Eugene Dietzgen Co. of Chicago, but an instruction manual for this model was published in 1946. A drawing in this manual shows the same scales that are on this slide rule. Although the model is advertised in Dietzgen's 1953–1954 catalog, the log and K scales are arranged very differently from this rule. Hence, the rule apparently dates from 1944 to 1952.
Three U.S. Naval Academy professors applied for the patents mentioned on this slide rule in 1937 and 1938. These patents dealt with arranging and coloring scales so that problems could be solved in the fewest steps. They were also cited on Keuffel & Esser slide rules, models 4080 and 4081. (See 1992.0437.01, 2007.0181.01, 318482, 334387, 1990.0687.01, and 1986.0790.03.) The inventors also wrote instruction manuals for K&E, such as 1987.0085.02 and 2007.0181.01.01. The scales on the patents match those on this rule, except that the positions of the LL0 and LL00 scales are reversed.
This slide rule was given to the Smithsonian in 1986 by the physicist Philip Krupen (1915–2001). Krupen received his BS from Brooklyn College in 1935, worked on the development of the proximity fuze during and after World War II, earned a master's degree in physics from George Washington University, and spent a total of 38 years working for the U.S. government before his retirement in 1973. It seems possible that he acquired the rule while working on his master's degree.
References: Robert Otnes, "Dietzgen Patents, Runners, and Log Log Scales," Journal of the Oughtred Society 5, no. 2 (1996): 45–48; H. Loren Thompson and Ovid W. Eshbach, The Dietzgen Maniphase Multiplex Decimal Trig Type Log Log Slide Rule No. 1732 (Chicago: Eugene Dietzgen Co., 1946), http://sliderulemuseum.com/Manuals/M179_Dietzgen1732Manual1946.pdf; Dietzgen School Catalog (Chicago, 1953), 27; Lyman M. Kells, Willis F. Kern, and James R. Bland, "Slide Rule" (U.S. Patent 2,170,144 issued August 22, 1939), and "Slide Rule" (U.S. Patent 2,285,722 issued June 9, 1942).
Location
Currently not on view
date made
1944-1952
maker
Eugene Dietzgen Company
ID Number
1986.0790.01
catalog number
1986.0790.01
accession number
1986.0790

Keuffel & Esser 4105 Webb's Stadia Cylindrical Slide Rule

This instrument consists of a wooden cylinder covered with paper scales, wooden handles at the ends of the cylinder, and a metal sleeve lined with felt. The sleeve, which is painted maroon, holds the cylinder. A slot 1.5cm wide and a paper scale run the length of the sleeve.
Description
This instrument consists of a wooden cylinder covered with paper scales, wooden handles at the ends of the cylinder, and a metal sleeve lined with felt. The sleeve, which is painted maroon, holds the cylinder. A slot 1.5cm wide and a paper scale run the length of the sleeve. For detailed information, see MA.333636. The only difference between the instruments is that the sleeve on this example has been decoratively painted in gold. Keuffel & Esser of New York sold this model for $5.00 from 1903 to 1923.
The School of Forestry of the University of Montana in Missoula donated this example to the Smithsonian in 1983. The School of Forestry was established at the State University of Montana (later Montana State University, now the University of Montana) in 1913. By 1921, courses taught in the school of forestry included—subject to student demand—a course on the slide rule. The course covered the theory and use of the Mannheim, Stadia, Polyphase, and Log rules.
References: State University of Montana, Annual Catalogue (Missoula, 1921), 125; "The Jack Burton Collection," Journal of the Oughtred Society 2, no. 1 (1993): 15–18; Bob Otnes, "The 31st (1903) and 32nd (1906) Editions of the K&E Catalogue" Journal of the Oughtred Society 11, no. 2 (2002): 24–32; Bob Otnes, "Keuffel & Esser Slide Rules 1909" Journal of the Oughtred Society 12, no. 1 (2003): 25–32.
Location
Currently not on view
date made
1903-1923
maker
Keuffel & Esser Co.
ID Number
1983.0472.01
catalog number
1983.0472.01
accession number
1983.0472

Concise CTCS-552 Circular Slide Rule

This white plastic circular slide rule is on a rectangular base that has a 4-inch ruler on the left side and a 10-cm ruler on the right. The top of the base is marked: CONCISE (/) CONVERSION TABLES (/) AND CIRCULAR SLIDE RULE. The slide rule has a D scale along the outer rim.
Description
This white plastic circular slide rule is on a rectangular base that has a 4-inch ruler on the left side and a 10-cm ruler on the right. The top of the base is marked: CONCISE (/) CONVERSION TABLES (/) AND CIRCULAR SLIDE RULE. The slide rule has a D scale along the outer rim. A rotating disc fastened with a metal grommet has C, CI, L, A, and K scales. There is a clear plastic rotating indicator. The bottom of the base is marked: MODEL CTCS-552.
The back of the instrument has a table of the chemical elements, arranged in alphabetical order, and a chart for converting temperatures from Celsius to Fahrenheit. The bottom of the back is marked: MODEL CTCS-552 (/) SAMA & ETANI, INC. GROTON MASSACHUSETTS U.S.A. (/) MADE IN JAPAN BY CONCISE.
A rectangular plastic card fits inside a slot in the base. The card provides various physical constants and conversions for length, area, weight, volume, decimal equivalents to 64ths, velocity, gas constant values, flow rate, pressure, and energy. One edge of the card is marked: ©1966 CONCISE INTERNATIONAL CO., LTD. The instrument and an instruction manual providing contact information for Sama & Etani and copyrighted 1960 both fit in a black plastic case.
Domenick Sama and Kenzi Etani designed this style of slide rule and conversion card when they were students at the Massachusetts Institute of Technology in 1954. By the mid-1960s, Concise, a firm in Tokyo, Japan, was manufacturing the device for Sama & Etani, who in turn were distributing Concise's products through their partnership headquartered in Groton, Mass. In Japan, the company operated as Etani Shoji Kaisha, Ltd. It closed by 1992. Concise began operating under the name Concise International Co., Ltd., in 1966 and remains in business as of 2012. For other slide rules by Concise, see 1996.0141.01, 2003.0012.01, and 2006.0173.01.
References: "Concise Corporate History," http://www.concise.co.jp/eng0731/history.html; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 153–154; "Groton Engineer, Associate Design Pocket Size Rule," Groton Town Diary 13 (March 1967): 17, http://books.gpl.org/greenstone/collect/towndiar/index/assoc/D5248.dir/Vol13_1967_017.pdf.
Location
Currently not on view
date made
after 1966
maker
Concise
ID Number
1985.0636.02
accession number
1985.0636
catalog number
1985.0636.02

Keuffel & Esser 68-2047 Log Log Duplex Decitrig Manual and S14-5 Care Instructions

ID number 1987.0085.01, a model 68–1210 Log Log Duplex Decitrig slide rule by Keuffel & Esser of New York, was received with these two paperback booklets. The citation information for the first booklet is: Lyman M. Kells, Willis F. Kern, and James R.
Description
ID number 1987.0085.01, a model 68–1210 Log Log Duplex Decitrig slide rule by Keuffel & Esser of New York, was received with these two paperback booklets. The citation information for the first booklet is: Lyman M. Kells, Willis F. Kern, and James R. Bland, K&E Slide Rule Manual: Log Log Duplex Decitrig, 4th ed. (New York: Keuffel & Esser Co., 1955). Kells, Kern, and Bland were all mathematics professors at the United States Naval Academy; they first prepared this manual in 1943. They designed the book for students to learn to operate slide rules on their own, without the aid of a teacher.
The manual covers the following topics: multiplication and division; the proportion principle and combined operations; squares and square roots, cubes and cube roots; trigonometry; the log log scales; and logarithms and the slide rule. Included are exercises, answers, and a historical note (featuring K&E's contributions to the development of slide rules). The manual was previously K&E model number 4187S.
The second pamphlet is small (4 X 3 inches) and titled: "How to Take Care of Your Slide Rule." It was copyrighted in 1944, 1949, 1958, and 1962. Users are to clean the slide rule only with a moistened cloth. Instructions are provided for adjusting and aligning the slide rule.
Location
Currently not on view
date made
1955-1962
author
Kells, Lyman M.
Kern, Willis F.
Bland, James R.
publisher
Keuffel & Esser Co.
ID Number
1987.0085.02
accession number
1987.0085
catalog number
1987.0085.02

Otis King's Pocket Calculator Model L Cylindrical Slide Rule

This six-inch cylindrical slide rule consists of a chromium-plated holder, a metal cylinder that slides into the holder, and a black metal tube that fits around and slides up and down on the cylinder.
Description
This six-inch cylindrical slide rule consists of a chromium-plated holder, a metal cylinder that slides into the holder, and a black metal tube that fits around and slides up and down on the cylinder. The rule is ten inches long when extended and equivalent to a linear slide rule 66 feet in length. Two short white lines on the tube and a black mark on the chrome cap at the end of the cylinder serve as the indicator. A paper spiral logarithmic scale is attached to the top half of the holder. A second, linear and logarithmic, paper scale is attached to the cylinder. The logarithmic scales are used to multiply and divide, and the linear scale is used to find logarithms.
The end of the cylinder is engraved: MADE IN (/) ENGLAND. At the top of the cylinder is printed: PATENT No 183723. At the bottom of the cylinder is printed: OTIS KING'S POCKET CALCULATOR; SCALE No 430. The top of the scale on the holder is printed: SCALE No 429; COPYRIGHT. The bottom is printed: OTIS KING'S PATENT No 183723. The end of the holder is machine engraved: T/0503. Engraved by hand (and upside-down to the serial number) is: C73.
The instrument is stored in a rectangular black cardboard box. A label on one end reads: Otis King's (/) Calculator (/) Model "L" (/) No. T0503. The slide rule arrived with instructions, 1987.0788.06, and an advertising flyer, 1987.0788.07. See also 1989.3049.02 and 1981.0922.09.
Otis Carter Formby King (b. 1876) of Coventry, England, received a British patent (183,723) for this instrument on August 31, 1922, and in 1923 he received patents 207,762 and 207,856 for improvements to the slide rule. From London, King filed a U.S. patent application, which he assigned to Carbic Limited, the London manufacturer of the slide rule, when that patent was granted in 1927. With co-inventor Bruce Hamer Leeson, King received U.S. Patent 1,820,354 for an "electrical remote control system" on August 25, 1931.
The serial number indicates that this example of Otis King's calculator was manufactured around 1960 to 1962. Howard Irving Chapelle (1901–1975), a naval architect, maritime historian, and curator of what was then the National Museum of History and Technology, donated it to the Smithsonian around 1969 to 1970.
References: Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 274, 281; Otis Carter Formby King, "Calculating Apparatus," (U.S. Patent 1,645,009 issued October 11, 1927); Richard F. Lyon, "Dating of the Otis King: An Alternative Theory Developed Through Use of the Internet," Journal of the Oughtred Society 7, no. 1 (1998): 33–38; Dick Lyon, "Otis King's Patent Calculator," http://www.svpal.org/~dickel/OK/OtisKing.html.
Location
Currently not on view
date made
1960-1962
maker
Carbic Limited
ID Number
1987.0788.01
catalog number
1987.0788.01
accession number
1987.0788

Pickett 140-ES Microline Student Duplex Slide Rule

This ten-inch yellow plastic duplex linear slide rule has a clear plastic indicator. The posts holding the rule together are also yellow plastic. The front of the base has LL2, LL3, and DF scales at the top and D, LL2, and LL3 scales at the bottom.
Description
This ten-inch yellow plastic duplex linear slide rule has a clear plastic indicator. The posts holding the rule together are also yellow plastic. The front of the base has LL2, LL3, and DF scales at the top and D, LL2, and LL3 scales at the bottom. The front of the slide has CF, CIF, L, CI, and C scales. The left end of the slide is marked: PickETT (/) MICROLINE (/) 140. The right end is stamped with the Pickett logo used between 1964 and 1975.
The back of the base has LL1, K, and A scales at the top and D, DI, and LL1 scales at the bottom. The back of the slide has B, S, ST, T, and C scales. The right end of the slide is also stamped with the 1964–1975 Pickett logo, featuring block letters with a triangle over the "I".
The rule slides into a black imitation leather stitched sheath. Earlier Pickett rules that were also intended for use by middle and high school students include 1991.0445.02 and 1984.1068.03.
Location
Currently not on view
date made
1964-1975
maker
Pickett Industries
ID Number
1989.0325.07
accession number
1989.0325
catalog number
1989.0325.07

Keuffel & Esser 1740 Thacher Cylindrical Slide Rule

This rule has a cylindrical hollow brass drum, which is covered with paper printed with 40 A scales. The first A scale runs from 100 to 112; the fortieth runs from 946 to 100 to 105. The paper is also printed in italics on the right side: Patented by Edwin Thatcher [sic], C.E.
Description
This rule has a cylindrical hollow brass drum, which is covered with paper printed with 40 A scales. The first A scale runs from 100 to 112; the fortieth runs from 946 to 100 to 105. The paper is also printed in italics on the right side: Patented by Edwin Thatcher [sic], C.E. Nov. 1st 1881. Divided by W. F. Stanley, London, 1882. A wooden handle is attached to each end of the drum, and the drum slides in both directions.
The drum fits inside an open rotating frame to which 20 brass slats are fastened. The slats are lined with cloth and covered with paper. The paper on each slat is printed with two B and two C scales. The first B scale runs from 100 to 112; the fortieth runs from 946 to 100 to 105. The first C scale runs from 100 to 334; the fortieth runs from 308 to 325. The frame is attached to a mahogany base, and the object is housed in a mahogany case. A paper label appears to have been removed from the top of the case.
A paper of directions and rules for operating THACHER'S CALCULATING INSTRUMENT is glued to the top front of the base. A metal tag attached to the top back of the base is engraved: Keuffel & Esser (/) New York. The front right corner of the frame is stamped with numbers: 57 and 35. Presumably one of these is the serial number, but which one is not clear. In either case, the low number and the shape of the frame suggest that this example is the earliest Thacher cylindrical slide rule in the collections. Model 1740 sold for $30.00 in 1887.
Robert B. Steffes of the U.S. Bureau of Labor Statistics donated this instrument to the Smithsonian in 1970.
See also MA.312866 and 1987.0107.08.
References: Wayne E. Feely, "Thacher Cylindrical Slide Rules," The Chronicle of the Early American Industries Association 50 (1997): 125–127; Catalogue of Keuffel & Esser (New York, 1887), 128. This was the first K&E catalog to list the model 1740.
Location
Currently not on view
date made
1882-1887
maker
Keuffel & Esser Co.
Stanley, William Ford
ID Number
1987.0808.01
catalog number
1987.0808.01
accession number
1987.0808

ECOBRA 1611 Duplex Slide Rule

This ten-inch aluminum linear duplex slide rule is coated with white enamel and has aluminum endpieces. One side of the base has scales for sin/cos, tg/ctg (tangent/cotangent), DF, D, and the square root of 1 – x2 (a Pythagorean or P scale).
Description
This ten-inch aluminum linear duplex slide rule is coated with white enamel and has aluminum endpieces. One side of the base has scales for sin/cos, tg/ctg (tangent/cotangent), DF, D, and the square root of 1 – x2 (a Pythagorean or P scale). On the slide are CF, CI, and C scales. The right end of the slide is marked: ECO BRA (/) Nr. 1611. The lower right corner of the base is marked: System (/) DARMSTADT. On the other side, the base has K, A, LL3, LL2, and LL1 scales. The slide has B, lg, and C scales. The numbers on the C, LL3, LL2, and LL1 scales are green, which is unusual. The indicator is plastic with aluminum edges. The letter Q is on the hairline on one side. On the other side, Q is on the hairline and W and PS are on shorter hairlines at the top of the indicator. These hairlines are for circle conversion and peripheral horsepower conversion, respectively.
The rule fits in a cardboard box covered with maroon synthetic leather. The top edge of the box is marked No. 1611. The front is marked with the Ecobra logo, and the back is marked MADE IN GERMANY.
Alwin Walther (1898–1967) of the Technische Hochschule in Darmstadt, Germany, developed the Darmstadt system of scales in 1934. His arrangement was aimed particularly at engineers. ECOBRA or Eco Bra was a brand name of Bayerische Reisszeugfabrik, a Nuremberg maker of drawing instruments that was purchased by Joseph Dietzgen in 1909. The company began producing slide rules before World War II, and after the war, Eugene Dietzgen Company of Chicago distributed ECOBRA rules in the United States. Metal rules were more popular in the United States than they were in Europe.
Reference: Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 34–35, 52–53.
Location
Currently not on view
date made
after 1945
maker
Ecobra
ID Number
1984.1071.04
accession number
1984.1071
catalog number
1984.1071.04

Fuller's Computing Telegraph Circular Slide Rule

This square yellow cardboard instrument has circular discs that rotate about a metal pin. The edges of the instrument are bound in red morocco leather. The disc on one side, Fuller's Time Telegraph, is designed to rapidly compute intervals between dates on the calendar.
Description
This square yellow cardboard instrument has circular discs that rotate about a metal pin. The edges of the instrument are bound in red morocco leather. The disc on one side, Fuller's Time Telegraph, is designed to rapidly compute intervals between dates on the calendar. It has linear scales for the 365 days of the year around the edge of the disc and on the surrounding circle on the frame. In addition to the name of the instrument and directions for finding the number of days and weeks between two dates, there is a copyright mark: Entered according to Act of Congress in the year 1845 by John E. Fuller in the Clerk's Office of the District Court of the State of Massachusetts (/) Eng[rave]d by G. G. Smith, Boston.
The disc on the other side, Palmer's Computing Scale, has logarithmic scales for area, distance, weight, and volume. The scales are marked with various equivalents, such as 5,280 feet to one mile. The surrounding circle on the frame has logarithmic scales for days, months, and costs per hundredweight. The center of the disc is marked: IMPROVED BY (/) FULLER. Near the top of the disc is marked: Use the inner circle for Dollars, Cents & Mills, (/) or Pounds, Shillings & Pence. Below the name of the instrument is a copyright mark: Entered according to Act of Congress, in the year 1843, by Aaron Palmer in the Clerks [sic]Office of the District Court of the State of Massachusetts (/) and by J. E. Fuller 1847. (/) Engraved by George G. Smith 186 Washington St. Boston. Above the name of the instrument is a second copyright mark: Entered according to Act of Congress, in the year 1847, by J. E. Fuller, In the Clerks [sic] office of the District Court of the United States, for the Southern District of New York.
The instrument fits in a folder with a dark green cover marked: FULLER'S (/) COMPUTING (/) TELEGRAPH. Inside the front cover is a 21-page booklet. The booklet, published in London, is titled: Fuller's Computing Telegraph: Multiplication and Division by one Single Process . . . To Which is Added Fuller's Complete and Perpetual Calendar. The booklet advertises the instrument's capabilities, explains how to solve various problems, and provides more detailed instructions. There are various tables for mechanics and engineers, including squares and cubes and the pressure of steam engines, and rules for solving problems of machines and of geometry. A circular statistical chart for the 35 states of the United States, separated into free and slave states, is also provided. Inside the back cover is a pictorial chart of 178 "mechanical movements," depicting gears and other machines carrying out rectilinear and circular motions. W. Nicholson prepared the chart, O. Pelton engraved it, and John E. Fuller published it.
This instrument was one of the first circular slide rules sold in the United States. It was introduced by Aaron Palmer of Boston, who made a prototype in 1841, took out a copyright for a computing scale in 1843, and published an account of it in 1844. He exhibited both the original and a smaller version at the 18th American Institute Fair, held in New York, N.Y., in 1845. There it may have attracted the attention of John Emery Fuller (1799–1878). By 1846, Fuller had acquired rights to Palmer's instrument and published an account of his improvements. He also added the time telegraph, which he had copyrighted in 1845. Fuller copyrighted the revised form of Palmer's scale in 1847. He exhibited the slide rule at the Crystal Palace exhibition in London in 1851 and prepared an English version of the instrument.
Bobby Feazel counted seven separate issues of the instrument, the four by Palmer listed above and three by Fuller (1847, 1848, 1871). The marks on this example correspond to the sixth issue, which was the English version and was manufactured between 1848 and 1871. The references in the instruction booklet to slave states and data from the 1860 Census suggest a date between 1861 and 1865.
References: Aaron Palmer, A Key to the Endless, Self-computing Scale, Showing Its Application to the Different Rules of Arithmetic, &c. (Boston: Smith & Palmer, 1844); Scientific American 1, no. 8 (October 16, 1845): 3; "The Eighteenth Annual Fair of the American Institute," American Whig Review 2, no. 5 (November 1845): 538–542, on 541; John E. Fuller, Improvement to Palmer's Endless Self-computing Scale and Key: Adapting It to the Different Professions . . . and Also to Colleges, Academies and Schools, With a Time Telegraph, Making, by Uniting the Two, a Computing Telegraph (New York, 1846; new ed., New York, 1851); "Fuller's Computing Telegraph," The Public Ledger, St. John's, Newfoundland, August 11, 1857, 2; Florian Cajori, "Aaron Palmer's Computing Scale" and "John E. Fuller's Circular Slide Rules," Colorado College Publication: Engineering Series 1 (1909): 111–122; Bobby Feazel, "Palmer's Computing Scale," Journal of the Oughtred Society 3, no. 1 (1994): 9–17; 4, no. 1 (1995): 5–8.
Location
Currently not on view
date made
1861-1865
maker
George Philip and Son
ID Number
1987.0284.01
catalog number
1987.0284.01
accession number
1987.0284

Gurley Cox's Stadia Computer Circular Slide Rule

This instrument consists of a plastic disc riveted to a plastic base. It is similar to a paper instrument of the same name (see 1987.0221.01).The base, just outside the disc, has a logarithmic scale that represents readings in feet of a stadia rod used with a transit telescope.
Description
This instrument consists of a plastic disc riveted to a plastic base. It is similar to a paper instrument of the same name (see 1987.0221.01).
The base, just outside the disc, has a logarithmic scale that represents readings in feet of a stadia rod used with a transit telescope. The base, just outside the disc, has a logarithmic scale that represents readings in feet of a stadia rod used with a transit telescope. The edge of the disc has two scales of functions of angles. Applying the first scale multiplies the stadia reading by 1/2 sin 2A, where A is the vertical angle of the transit telescope. This multiplication gives the difference in elevation of the transit and the stadia rod, in feet. The second scale multiplies the stadia reading by the square of cos A, to find the horizontal distance of the rod in feet.
The back of the instrument bears an advertisement for W. & L. E. Gurley, a maker of instruments in Troy, N.Y. A transit is depicted; it appears to be Gurley's Explorers [sic] precise transit. This was the smallest and lightest Gurley transit, shown in the Gurley catalogs for 1910 and 1912 (with a different image than is on this rule) and 1921 (with same image as on rule), but not the 1928 catalog. The 1921 catalog advertises the celluloid form of the Cox stadia computer and indicates that it sold for 75 cents.
A maker's mark at the bottom of the back of the computer is not legible, but the firm of Whitehead and Hoag of Newark, N.J., is known to have manufactured the instrument for Gurley in the second quarter of the 20th century.
References: W. & L. E. Gurley, Catalogue of Gurley Engineering Instruments (Troy, N.Y., 1921), 50; Florian Cajori, "A Stadia Slide-Rule," Engineering News 43 (April 5, 1900): 232; Laine Farley, "Whitehead & Hoag Celluloid Bookmarks," http://www.bibliobuffet.com/on-marking-books-columns-195/archive-index-on-marking-books/1039-whitehead-a-hoag-celluloid-bookmarks-053109.
Location
Currently not on view
date made
ca 1921
maker
W. & L. E. Gurley
ID Number
1987.0221.02
accession number
1987.0221
catalog number
1987.0221.02

Dietzgen 1767 National Simplex Slide Rule

In the 1950s, several manufacturers sold inexpensive plastic slide rules for use by students. This one-sided, ten-inch example, sold by the Chicago firm of Dietzgen has K, S, A, D, T, and L scales on the base. B, CI, and C scales are on the slide.
Description
In the 1950s, several manufacturers sold inexpensive plastic slide rules for use by students. This one-sided, ten-inch example, sold by the Chicago firm of Dietzgen has K, S, A, D, T, and L scales on the base. B, CI, and C scales are on the slide. The rule has a clear plastic frameless indicator with a hairline and black plastic endpieces. The top right corner of the base is marked: NATIONAL. Both ends of the slide are marked: DIETZGEN (/) NO. 1767. Both ends of the bottom of the base are marked: MADE (/) IN (/) U. S. A. A cream-colored synthetic leather case is marked: R. LAWSE. The rule was received with an instruction manual, 1988.0367.02.
According to Peter Hopp and Bruce Babcock, Dietzgen manufactured model 1767 from 1955 to 1959. An earlier version of the National, the 1767P, had a different set of scales. It was manufactured from 1941 to 1952 and sold in 1952 for $1.75 or $18.25 for a dozen.
References: Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 160; Bruce Babcock, "Dietzgen Catalog Matrix," Journal of the Oughtred Society 5, no. 2 (1996), http://sliderulemuseum.com/Manuals/Dietzgen_CatalogMatrix_BruceBabcock1996_chart.jpg.
Location
Currently not on view
date made
1955-1959
maker
Eugene Dietzgen Company
ID Number
1988.0367.01
accession number
1988.0367
catalog number
1988.0367.01

Instructions for C-Thru Pocket Slide Rule

This single sheet of paper was received with 1988.0807.02. It describes how to read the scales for two inexpensive student slide rules, the pocket-sized model 27 and ten-inch model 88, made by the C-Thru Ruler Company of Hartford, Conn.
Description
This single sheet of paper was received with 1988.0807.02. It describes how to read the scales for two inexpensive student slide rules, the pocket-sized model 27 and ten-inch model 88, made by the C-Thru Ruler Company of Hartford, Conn. The postal code indicates a date between 1943 and 1963. The back of the sheet is stamped: GEORGE A. NORTON (/) 132 SWANN ROAD (/) WASHINGTON 23, D.C.
Location
Currently not on view
date made
1943-1963
maker
C-Thru Ruler Company
ID Number
1988.0807.06
accession number
1988.0807
catalog number
1988.0807.06

Keuffel & Esser 4081-5 Log Log Decitrig Duplex Slide Rule

This 20-inch mahogany slide rule is coated with white celluloid on both sides and held together with metal end pieces. A glass indicator has plastic edges held together with metal screws. .
Description
This 20-inch mahogany slide rule is coated with white celluloid on both sides and held together with metal end pieces. A glass indicator has plastic edges held together with metal screws. . There are LL02, LL03, DF, D, LL3, and LL2 scales on one side of the base, with CF, CIF, CI, and C scales on the slide. The right end of the slide is marked in red: © (/) K + E. On the other side of the base, there are LL01, L, K, A, D, DI, and LL1 scales, with B, T, SRT, and S scales on the slide. The left end of the slide is marked: 450243. The left end of the top and the bottom of the base are both marked: 243. Keuffel & Esser used this arrangement of scales on this model from 1955 to 1962; the serial number suggests this example was made around 1958.
The top edge of the rule is marked: PATS. PEND. MADE IN U.S.A. 4081-5 LOG LOG DUPLEX DECITRIG ® COPYRIGHT 1947 BY KEUFFEL & ESSER CO. PATS. 2,500,460 2,168,056 2,170,144 2,285,722 2,422,649. These patents were issued between 1939 and 1950. They dealt with the arrangement of scales on a slide rule, in particular so that the user could solve multistep problems without having to write down intermediate settings, and with the placement of a legend to make placing the decimal point easier.
The rule slides into an orange leather case lined with chamois. The flap is marked: K + E. Inside the flap is written: PHIL (/) KRUPEN. In 1959, model 4081-5 sold with a leather case for $50.50. Compare to ten-inch versions of model 4081, MA.318482 and MA.334387.
This slide rule was given to the Smithsonian in 1986 by the physicist Philip Krupen (1915–2001). Krupen received his BS from Brooklyn College in 1935, worked on the development of the proximity fuze during and after World War II, earned an MS in physics from The George Washington University, and spent a total of 38 years working for the U.S. government before his retirement in 1973.
References: Carl M. Bernegau, "Slide Rule" (U.S. Patent 2,168,056 issued August 1, 1939); Lyman M. Kells, Willis F. Kern, and James R. Bland, "Slide Rule" (U.S. Patent 2,170,144 issued August 22, 1939); Lyman M. Kells, Willis F. Kern, and James R. Bland, "Slide Rule" (U.S. Patent 2,285,722 issued June 9, 1942); James R. Bland, "Slide Rule" (U.S. Patent 2,422,649 issued June 17, 1947); Herschel Hunt, "Slide Rule" (U.S. Patent 2,500,460 issued March 14, 1950); Clark McCoy, "Collection of Pages from K&E Catalogs for the 4081-3 Family of Slide Rules: 4080-3 & 4081-3 Family Groups," http://www.mccoys-kecatalogs.com/KEModels/ke4081-3family.htm; Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; K + E Price List, Applying to the 42nd Edition Catalog (Hoboken, N.J., 1959), 73; Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 71–75; "Philip Krupen," The Washington Post, February 23, 2001, B07.
Location
Currently not on view
date made
1955-1962
date received
1986
maker
Keuffel & Esser Co.
ID Number
1986.0790.03
accession number
1986.0790
catalog number
1986.0790.03

Ladew Belting Strength Computer Circular Slide Rule by Whitehead and Hoag

Leather belting produced from cowhide tanned in a solution with ground oak bark had been manufactured in New York City from the 19th century.
Description
Leather belting produced from cowhide tanned in a solution with ground oak bark had been manufactured in New York City from the 19th century. By the end of the century, the firm of Fayerweather & Ladew in Glen Cove, N.Y., had developed methods of waterproofing leather belting so that it could be used in wet and humid conditions. After the death of Edward R. Ladew in 1905, the firm operated as Estate of Edward R. Ladew. It was renamed Edw. R. Ladew Co., Inc., about 1919, and in 1920 it was sold to Graton & Knight Manufacturing Co. of Worcester, Mass.
To publicize its products, the company began distributing the Ladew Belting Strength Computer in 1914. This tan circular slide rule was made by the Whitehead & Hoag Company of Newark, N.J., under a June 6, 1905, patent for printing on pyroxylin (celluloid). It has a rotating disc and another rotating circular segment, pivoted about a metal rivet and attached to a rectangular celluloid base. The logarithmic scales allow computation of the horsepower a leather belt of known quality will transmit, given the width of the belt, the diameter of the pulley, and the rate of revolution of the pulley. The scales also make it possible to calculate the working strain of the belt, according to the kind of belt used and the horsepower transmitted. Instructions are provided on the back of the instrument.
For a linear slide rule for computations relating to cloth belting, see the Computer for Belting and Computer for Shafting made by J. A. & W. Bird & Co. of Boston (1988.0323.02). For information on Whitehead & Hoag, see 1984.1080.01.
References: Frank R. Norkross, A History of the New York Swamp (New York: The Chiswick Press, 1901), 103–107; Richard E. Roehm, "Process of Printing Upon Pyroxylin Materials" (U.S. Patent 791,503 issued June 6, 1905); Library of Congress, Catalogue of Copyright Entries, part 1, group 2, n.s., vol. 11, no. 8 (Washington, D.C., 1914): 754; "Ladew Belt Mill Sold," New York Times (February 13, 1920), 23; "Business Changes," Steam 25, no. 4 (May 1920): 145; accession file.
Location
Currently not on view
date made
1914-1920
maker
Whitehead & Hoag Company
ID Number
1988.0350.01
accession number
1988.0350
catalog number
1988.0350.01

Harvard Project Physics Circular Slide Rule

The slide rule is a device to assist in multiplication, division and other mathematical operations. Invented in the 1600s, it became popular in American science and engineering in the 1890s.
Description
The slide rule is a device to assist in multiplication, division and other mathematical operations. Invented in the 1600s, it became popular in American science and engineering in the 1890s. By the 1930s, slide rule use was taught in high schools.
From 1962 until 1972, Harvard University faculty cooperated with others in developing a humanistically oriented high school physics course that might attract more students to the subject. Staff developed not only textbooks, handbooks, transparencies and film loops but this extremely simple and inexpensive plastic slide rule.
The instrument has two circular logarithmic scales for multiplication and division (most elementary slide rules also had scales for taking squares and square roots). There also are linear scales of inches and centimeters.
A stylized bubble chamber image, the logo of Project Physics, appears over the rule. The slide rule was designed so that "Harvard Project Physics" showed just over the shirt pocket of a boy carrying it. This design may reflect the fact that there were no female undergraduates at Harvard College at the time. Not long after this slide rule was made, inexpensive pocket calculators displaced the slide rule.
Location
Currently not on view
date made
ca 1965
ID Number
1988.0539.01
accession number
1988.0539
catalog number
1988.0539.01

Hemmi 153 Duplex Slide Rule

This bamboo rule is coated on both sides and its long outer edges with white celluloid. The rule is held together with metal posts. The glass indicator has a metal frame with bamboo and celluloid sides.
Description
This bamboo rule is coated on both sides and its long outer edges with white celluloid. The rule is held together with metal posts. The glass indicator has a metal frame with bamboo and celluloid sides. The rule is marked in the lower right corner of the base front: "SUN" (between two drawings of the sun) (/) HEMMI (/) MADE IN JAPAN. The scales are 25 cm (9-7/8") long.
Hemmi designed this model for electrical engineers. The front of the base has L, K, A, D, T, and Gθ scales. The front of the slide has B, CI, and C scales. The back of the base has θ, Rθ, P, LL3, LL2, and LL1 scales, with Q, Q', and C scales on the back of the slide. The P, Q, and θ scales were used for trigonometric relationships in right triangles and for hyperbolic functions. They were developed in 1929 for Hemmi rules and credited to Sadatoshi Betsumiya and Jisuke Miyazaki. These scales were not used in the West, and even Hemmi did not use these scales on all of its models.
The rule is stored in a black rectangular cardboard box which is opened by removing the right end. This end is marked in silver: "SUN" (between two drawings of the sun (/) "HEMMI" BAMBOO (/) SLIDE RULE. There are two stars where the box joins together.
Hemmi, a Japanese firm, manufactured this model of slide rule between 1933 and 1967. From 1942 through 1946, Hemmi exports to the English-speaking world were severely limited. From 1946 to 1950, Hemmi rules were marked, MADE IN OCCUPIED JAPAN. After 1950, Hemmi rules were stamped with codes indicating the year and month of manufacture. Hence, it seems likely that this rule was made between 1933 and 1942.
Dr. Robert P. Multauf, who owned this rule, was an early director of the Museum of History of Science and Technology (later the National Museum of American History). Previously, he served in the U.S. Navy in postwar Japan.
References: Brian Borchers and Noël H. Cotter, "The Sun Hemmi System of Trigonometric and Hyperbolic Scales," Journal of the Oughtred Society 9, no. 2 (2000): 28–31; Hisashi Okura, "Hyperbolic Scale Rule" (U.S. Patent 2,079,464 issued May 4, 1937).
Location
Currently not on view
date made
1933-1942
maker
SUN HEMMI JAPAN CF
ID Number
1989.0443.01
catalog number
1989.0443.01
accession number
1989.0443

Pickett 904-ES Decimal Keeper Duplex Slide Rule

This aluminum duplex slide rule has a yellow coating and a clear plastic indicator. The "ES" in the model number refers to the rule's "Eye Saver" yellow color. The rule and indicator are held together with aluminum braces that have protruding grooves.
Description
This aluminum duplex slide rule has a yellow coating and a clear plastic indicator. The "ES" in the model number refers to the rule's "Eye Saver" yellow color. The rule and indicator are held together with aluminum braces that have protruding grooves. The front of the rule has K, A, DF, D, and L scales, with CF, S, T, CI, and C scales on the slide. The scales are 9-1/2 inches long. The back of the rule has a D* scale, with T*, S* Cl*, and C* scales on the slide. Instead of covering the typical one decade of C and D scales, the scales with asterisks cover twenty decades, from 1010 to 10-10. These scales helped inexperienced users keep track of the decimal point. They performed their calculation first on the back, to determine the order of magnitude, and then a second time on the front, to make the answer precise to three significant figures.
The front of the slide is marked: MODEL 904-ES (/) TRIG AND (/) DECIMAL KEEPER (/) SPEED RULE. A Pickett logo is at the other end of the slide, with the number 47 printed above the logo. The back of the rule is marked: PATENT (/) APPLIED FOR; DECIMAL KEEPER; PICKETT & ECKEL, INC. (/) CHICAGO 3, ILL. - ALHAMBRA, CAL. The logo on this rule is that used by Pickett from 1958 to 1962. The shape and material of the cursor and the braces suggest a date of 1957–1959. Hence, the object appears to have a rough date of 1958–1959.
The donor patented an "automatic decimal point slide rule" and assigned the patent to Pickett. He also distributed Pickett slide rules through his own mail order firm of Devonics, Inc.
The rule was received in a plastic bag. For somewhat related documentation, see 1995.0126.04. See also Lawrence J. Kamm, "Automatic Decimal Point Slide Rule" (U.S. Patent 2,893,630 issued July 7, 1959).
References: Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries (Mendham, N.J.: Astragal Press, 2000), 75–76, 100; Ron Manley, "Pickett 904-ES – Trig and decimal keeper," http://www.sliderules.info/collection/10inch/090/1096-pickett-904.htm; "Slide Rule Dates and Time-Lines," http://sliderulemuseum.com/SR_Dates.htm.
Location
Currently not on view
date made
ca 1958-1959
maker
Pickett & Eckel, Incorporated
ID Number
1995.0126.01
accession number
1995.0126
catalog number
1995.0126.01

Sheets, Gradeulator, Instructions for Use

In the early 1970s, Frank J. Thomas (1924-1976), a construction engineer from Topeka, Kansas, invented the "Gradeulator", a circular slide rule. These photocopied sheets give instructions on its use.
Description
In the early 1970s, Frank J. Thomas (1924-1976), a construction engineer from Topeka, Kansas, invented the "Gradeulator", a circular slide rule. These photocopied sheets give instructions on its use. They were received with an example of the device (see 1990.0509.01).
Location
Currently not on view
date made
1973
maker
Thomas, Frank J.
ID Number
1990.0509.02
accession number
1990.0509
catalog number
1990.0509.02

Pickett Elementary Simplex Math Slide Rule Instructions

Maurice L. Hartung, a mathematics professor at the University of Chicago, wrote this 48-page booklet in 1965. It sold separately for $1.00, but it was also included with Pickett's N901 simplex slide rule (1995.0126.02). John W.
Description
Maurice L. Hartung, a mathematics professor at the University of Chicago, wrote this 48-page booklet in 1965. It sold separately for $1.00, but it was also included with Pickett's N901 simplex slide rule (1995.0126.02). John W. Pickett marketed that rule to teachers and students from the second grade up.
The instructions are structured as a workbook, requiring students to fill in a blank for each numbered item. The items both explain the slide rule's functions and test students' comprehension. The answers are printed in the right margin of each page. The manual covers addition, subtraction, multiplication, division, proportion and percent, scientific notation, decimal points, squares and square roots, and the C, D, CI, and L scales. The inside back cover advertises the benefits of Pickett all metal slide rules and provides instructions for caring for the slide rule.
The ten-digit phone number for Pickett, Inc., in Santa Barbara, Calif., is written in ink on the back cover of the booklet, above the printed copyright date and company address.
References: Greg Scott, "Pickett – Elementary Simplex Math Slide Rule," http://sliderule.ozmanor.com/man/man020-pickn901es-01.html.
Location
Currently not on view
date made
after 1965
date received
1995
author
Hartung, Maurice L.
ID Number
1995.0126.02.01
accession number
1995.0126
catalog number
1995.0126.02.01

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