Index by Material

An image of various slide rules from the collection of the Division of Medicine and Science at the National Museum of American History.

Slide rules were sometimes distinctive by the materials from which they were made. Early rules were often made from boxwood and other woods. By the late 19th century, German manufacturers and Keuffel & Esser of New York City had not only switched to the more uniform and durable mahogany but were also coating the wood with early forms of plastic (celluloid). Around the turn of the 20th century, Japanese firms used bamboo, which did not expand and shrink as much as wood, thus reducing errors in the results of calculations. Later, Pickett slide rules were notable for their aluminum construction and proprietary yellow color. Although the rules tended to be less affordable and popular than wooden rules, manufacturers have used brass and other metals throughout the history of slide rules. Plastic and paper became increasingly widespread for inexpensive rules in the 20th century.

AluminumChromiumMetalSterling Silver
BambooIvoryPaperWood
BoxwoodMagnesiumPlasticYew
BrassMahogany  
Search term: *:* Set Name: Medicine and Science: Mathematics Clear All

Keuffel & Esser 4078 Duplex Slide Rule

This 20-inch mahogany linear slide rule is coated on the front and back with white celluloid; the edges are bare. The scales are labeled on the right end of each side. On both sides, the top of the base has an A scale, and the bottom of the base has a D scale.
Description
This 20-inch mahogany linear slide rule is coated on the front and back with white celluloid; the edges are bare. The scales are labeled on the right end of each side. On both sides, the top of the base has an A scale, and the bottom of the base has a D scale. On one side, the slide has B and C scales; on the other, the slide has BI and CI scales. The rule has two indicators: the original brass double-chisel style indicator, and the frameless glass with plastic edges that Keuffel & Esser adopted in 1915. According to the donor, the second indicator was acquired some years after the original slide rule.
The bottom of the base on one side and the chisel indicator on the other side are both marked: KEUFFEL & ESSER Co. NEW-YORK. The bottom of the base is also engraved: CHAS. C. BRUSH 1901. The symbol for pi has also been scratched on the D scale on that side. On the other side, the bottom of the base is marked: PAT. OCT. 6. 1891. One edge of the frameless indicator is marked: K&E.CO.N.Y. (/) PAT.8.17.15. For information on these patents, see MA.318477 and MA.318475.
The cardboard case is covered with brown morocco leather. It is marked: KEUFFEL & ESSER CO. (/) DUPLEX (/) SLIDE RULE. See the similar case for MA.326613.
According to the donor, the instrument was used by his father, Charles C. Brush (1880–1968), who graduated from high school in Philadelphia in 1898 and subsequently studied at the Franklin Institute. He received a certificate from the School of Naval Architecture there in 1904. The model 4078 is only listed in Keuffel & Esser catalogues for 1901 and 1903, priced at $16.50. The catalog evidence and the date on the slide rule make it reasonable to suppose that Brush acquired the slide rule in the course of his studies. Charles C. Brush was then associated with the Bureau of Lighthouses from 1917 to 1939. When the Lighthouse Service ended in 1939, he served as a marine engineer in the engineering department of the U.S. Coast Guard until his retirement in 1944.
References: Catalogue of Keuffel & Esser Co., 30th ed. (New York, 1900–1901), 296; Catalogue of Keuffel & Esser Co., 31st ed. (New York, 1903), 306; accession file.
Location
Currently not on view
date made
1901-1903
maker
Keuffel & Esser Co.
ID Number
1977.0370.01
accession number
1977.0370
catalog number
335926

Pickett N1010-ES Trig Duplex Slide Rule

This ten-inch aluminum linear slide rule has a yellow ("eye saver") coating and a nylon indicator. The front of the base has L, DF, D, and DI scales, with B, ST, T, S, and C scales on the slide. The left end of the slide is marked: MODEL (/) N1010-ES (/) TRIG.
Description
This ten-inch aluminum linear slide rule has a yellow ("eye saver") coating and a nylon indicator. The front of the base has L, DF, D, and DI scales, with B, ST, T, S, and C scales on the slide. The left end of the slide is marked: MODEL (/) N1010-ES (/) TRIG. The right end of the slide has the style of Pickett logo used between 1958 and 1962, with MADE IN U.S.A. printed below the logo.
The back of the base has K, A, D, and DI scales, with CF, CIF, CI, and C scales on the slide. The left end of the slide is marked: COPYRIGHT 1959© (/) PATENT APPLIED FOR. The right end of the slide is marked: PICKETT INC. (/) Santa Barbara, Calif. Compare to 1993.0559.01.
A black leather case is lined in pink plastic. The triangular Pickett logo stamped in gold below the slot for the case's flap is wearing away. The back of the case has a metal ring for attaching to a belt. Inside the flap is the name and address of David D. Goldberg, who was apparently the first owner of the instrument. It then passed to Janis Popowicz, who donated the rule to the Smithsonian while she was technician in the Division of Mathematics from September 1977 to April 1978. She used it as a high school physics student.
As is the case for many Pickett slide rules (e.g., 1991.0445.02), the dating for this instrument is ambiguous. The copyright date, logo, shape of the posts, and location of the grooves (on the slide instead of on the base) are all consistent with a date between 1958 and 1962. However, Pickett & Eckel only moved to Santa Barbara, Calif., and took the new name of Pickett Industries in 1964. The logo changed in 1962 and again in 1964. See the company history with 1998.0119.02.
References: Rodger Shepherd, "Pickett Metal Slide Rules," Journal of the Oughtred Society 1, no. 1 (1992): 5–8; James A. Coontz, "You Think You Have Moving Day Problem?" Los Angeles Times, January 16, 1964, B8; Michael P. O'Leary, "Pickett from a Manufacturing Perspective," Journal of the Oughtred Society 10, no. 1 (2001): 13–14; Maurice L. Hartung, A Teaching Guide for Slide Rule Instruction (Chicago: Pickett & Eckel, Inc., 1960), http://www.sphere.bc.ca/test/pickett/pickett_training.pdf.
Location
Currently not on view
date made
ca 1962
maker
Pickett Industries
ID Number
1977.1113.01
catalog number
336446
accession number
1977.1113

Makeba-Kombinator Pencil Slide Rule

This instrument combines a mechanical pencil and a slide rule. The pencil has a metal body surrounding a black plastic tube, which is pulled out to move the scales. Four white plastic logarithmic scales are glued to the pencil.
Description
This instrument combines a mechanical pencil and a slide rule. The pencil has a metal body surrounding a black plastic tube, which is pulled out to move the scales. Four white plastic logarithmic scales are glued to the pencil. One pair of scales is divided logarithmically from 1 to 100 (as A and B scales), and the other pair is divided logarithmically from 1 to 10 (as C and D scales).
The black plastic tube (underneath one of the A/B scales) is marked: MAKEBA-KOMBINATOR. The black plastic tube surrounds a metal tube and spring, which connect a metal tip and a plastic pusher. A pencil lead is inside the metal tube. A sliding plastic indicator is in a metal frame with a ridged edge for gripping.
Makeba was established in Bautzen, Germany, in 1922. By the 1950s, it was a sub-brand of Markant, an East German company that copied designs for Pelikan fountain pens as late as the 1970s.
Reference: Der neue Makeba-Kombinator: Fallstift mit Rechenschieber (Bautzen, East Germany: VEB Füllhalterfabrik Makeba, 1957). According to Worldcat, a copy of this publication is in the Deutsche Nationalbibliothek in Leipzig. See http://d-nb.info/574971327.
Location
Currently not on view
date made
ca 1957
maker
Makeba
ID Number
1977.1120.01
catalog number
336447
accession number
1977.1120

Felsenthal Graphical Site Table

Computing devices have been manufactured for military purposes since at least the early 17th century. Around the end of World War II, the Chicago firm of Felsenthal designed an instrument like a slide rule for aiming a variety of howitzers, or short cannons, used by the U.S.
Description
Computing devices have been manufactured for military purposes since at least the early 17th century. Around the end of World War II, the Chicago firm of Felsenthal designed an instrument like a slide rule for aiming a variety of howitzers, or short cannons, used by the U.S. Army, including the 155 mm size. The Fort Sill, Okla., bookstore sold these slide rules for $1.50.
This wooden graphical site table has a white coating on both sides. The indicator is clear plastic with wooden edges held together with brass screws. The bottom of the base has a scale marked: Site and Vertical Interval. On one side, the slide has a scale for range and scales for the Target Above Gun (TAG) and Target Below Gun (TBG) with charges of 4 or 5. This side is marked: HOW., 155-MM (/) MI (/) SHELL, M107 (/) FT 155-Q-2. The other side of the slide has another scale for range and TAG/TBG scales for charges of 1, 3, 6, and 7. The back of the instrument has instructions and examples of use. Both sides of the slide, the base, and the back are all marked: 25045.
Compare to 1977.1141.27, whose markings suggest that this instrument was made before 1964. For a graphical firing table, see 2005.0271.02. For Felsenthal company history, see 1977.1141.01 and 1977.1141.02.
References: "Graphical Site Table," The Field Artillery Journal 35, no. 9 (September 1945): 548; Elizabeth R. Dickinson, "The Production of Firing Tables for Cannon Artillery," U.S. Army Ballistic Research Laboratory, Report No. 1371 (Aberdeen (Md.) Proving Ground, November 1967), 75–80; Johnnie F. Pearson, Jr., "Fire Direction Center Operations in Viet Nam," 5, 19, http://83rd_artillery.home.comcast.net/~83rd_artillery/Artillery_Info/Artillery_Misc_Files/FDC_Operation_2012_040312.pdf; accession file.
Location
Currently not on view
date made
mid-20th century
Date made
pre-1964
maker
Felsenthal Instrument Co.
ID Number
1977.1141.26
catalog number
336410
accession number
1977.1141

Felsenthal Graphical Site Table

This one-sided wooden instrument, similar to a slide rule, was designed in 1964 by Felsenthal Instrument Company but, according to the accession file, made at the Fort Sill Bookstore in Oklahoma. It was used to position a 155 mm howitzer armed with high-explosive M107 shells.
Description
This one-sided wooden instrument, similar to a slide rule, was designed in 1964 by Felsenthal Instrument Company but, according to the accession file, made at the Fort Sill Bookstore in Oklahoma. It was used to position a 155 mm howitzer armed with high-explosive M107 shells. The indicator is clear plastic with wooden edges held together with brass screws.
The bottom of the base has a scale labeled Site and Vertical Interval. The lower right corner of the base is marked: Rule 2 (/) Apr 64. On one side, the slide has a scale for range and scales for the Target Above Gun (TAG) and Target Below Gun (TBG) with charges of 5 or 6. The other side of the slide has another scale for range and TAG/TBG scales for charges of 3, 4, and 7. Tables for the observer's position are on the left and right ends of the slide on both sides. Both sides are marked: HOW 155 mm (/) FT 155-AH-1 (/) PROJ, HE, M107 Rule 2 (/) Apr 64.
Tables for angling guns to the left and right at various distances are printed under the slide. The back of the instrument has instructions and examples of use. The markings suggest that this rule was distributed in a white bag. Compare to 1977.1141.26, which may be an earlier version of the instrument.
Location
Currently not on view
date made
1964
maker
Felsenthal Instrument Co.
ID Number
1977.1141.27
catalog number
336411
accession number
1977.1141

Pickett 14 Military Duplex Slide Rule

This ten-inch aluminum linear slide rule is coated with yellow plastic and has a flat nylon indicator. The back of the base has LL1, LL2, A, D, LL3, and LL4 scales, with B, T, ST, S, K, and C scales on the slide. The left end of the slide is marked: MODEL 14 (/) U.S.
Description
This ten-inch aluminum linear slide rule is coated with yellow plastic and has a flat nylon indicator. The back of the base has LL1, LL2, A, D, LL3, and LL4 scales, with B, T, ST, S, K, and C scales on the slide. The left end of the slide is marked: MODEL 14 (/) U.S. The right end has the Pickett triangular logo used between 1958 and 1962. The style of the grooved stamped aluminum posts is also consisted with this timeframe.
The top front of the base has scales for "opposite angle" (sine) in both degrees and mils; the top bottom of the base has "Distance D" and A scales. The front of the slide has scales for apex angle (in both mils and degrees), tangent, sine-tangent, sine, and base. The top center of the base is marked: U.S. MILITARY SLIDE RULE.
Pickett & Eckel, Inc., of Chicago and Alhambra, Calif., made this instrument for computations related to the use of field artillery. It fits in an orange-red leather case that has the Pickett logo and US stamped in gold on the front and a metal loop on the back for suspension from a belt. The case is lined with white plastic. A white plastic "data strip" slides into a slot on the case. The strip contains diagrams and equations for trigonometric functions, traverse computations, azimuth and distance from coordinates, triangle computation, and the distance to an artillery target.
The case fits in a brown, black, white, and yellow paper box. The box and its insert are repeatedly marked: ALL METAL SLIDE RULE a rule for every need. The Pickett logo appears between the two segments of the mark. The end of the box once bore a paper tag: 1 UNIT - FSN - 7520 - 656 - 0660 (/) Slide Rule – Military, Field Artillery (/) With Data Strip and Case MIL-S-20195B (/) Mfg. Contr.; PICKETT & ECKEL, INC. Model No. 14.
The object comes from the Felsenthal Collection of computing devices. (See Felsenthal's company history with 1977.1141.02.) Donor Ben Rau suggested a date of 1965 for this slide rule, but it was probably made a few years earlier. Compare to the box collected with 1995.0126.02.
References: Accession File; Tom Bullock, "Pickett 14 U.S. military slide rule," December 8, 2009, http://www.tbullock.com/sliderule.html; Clark McCoy, "Highlights of the A. J. Boardman Collection of Pickett Slide Rules," Journal of the Oughtred Society 16, no. 2 (2007): 10–14.
Location
Currently not on view
date made
1958-1962
maker
Pickett & Eckel, Incorporated
ID Number
1977.1141.29
catalog number
336413
accession number
1977.1141

Koehler Trim-Numeral Calculator

This plastic green and white slide rule carries out calculations related to the capacity, draft, and resistance of cargo tankers able to carry up to 26,700 deadweight metric tons of petroleum or petroleum products. Eight metal rivets hold the rule together.
Description
This plastic green and white slide rule carries out calculations related to the capacity, draft, and resistance of cargo tankers able to carry up to 26,700 deadweight metric tons of petroleum or petroleum products. Eight metal rivets hold the rule together. The front is marked: KOEHLER TRIM-NUMERAL CALCULATOR (/) 26700 D.W.T. TANKERS. The bottom of the front of the slide is marked: MARKETED BY JEFKO PRODUCTS COMPANY, 100 OAKLAND ROAD, MAPLEWOOD, NEW JERSEY. The back of the rule and the back of the slide are both marked: COPYRIGHT 1954 BY J. F. KOEHLER.
According to the accession file, this instrument was made by Felsenthal Instrument Company in 1954 as model number FDJ-23. For company history, see 1977.1141.01 and 1977.1141.02. The address for JEFKO Products is a single-family home constructed in 1925. A New Jersey engineer named J. Franklin Koehler (b. 1927) earned a B.S. in naval architecture and marine transportation from the Massachusetts Institute of Technology in 1951 with a thesis titled "Influence of Rising Operating Costs on Relative Economic Operation of Higher Speed Cargo Vessels."
Location
Currently not on view
date made
1954
maker
Felsenthal Instrument Co.
ID Number
1977.1141.38
catalog number
336422
accession number
1977.1141

Felsenthal FAE-15 Stadia Computer Circular Slide Rule

This white plastic circular slide rule consists of a disc riveted to a square backing. The backing has a logarithmic scale of readings of a stadia rod used with a transit telescope, in feet. The disc has two logarithmic scales of angles.
Description
This white plastic circular slide rule consists of a disc riveted to a square backing. The backing has a logarithmic scale of readings of a stadia rod used with a transit telescope, in feet. The disc has two logarithmic scales of angles. The first scale gives the difference in elevation of the transit and the stadia rod, in feet. It represents multiplying the stadia reading by 1/2 sin 2A, where A is the vertical angle of the transit telescope. The second scale finds the horizontal distance of the rod in feet and represents multiplying the stadia reading by the square of cos A. There is no indicator.
The instrument is marked on the front: STADIA COMPUTER. The interior of the disc has DIRECTIONS FOR USE and a table providing the quantity to be added when a constant is used in measuring stadia. On the back, the rule is marked: 6675-664-4676 (/) CONTRACT NO. DSA 700-68-M-AF86 (/) FELSENTHAL INSTRUMENTS CO. (/) CHICAGO, ILLINOIS (/) 22040 (/) MFR'S PART NO. FAE-15. It has a blue plastic case with snaps and a holder for a label. This object was donated with a second, duplicate Felsenthal stadia computer, which was assigned the same catalog number.
The instrument resembles Cox's Stadia Computer (see 1987.0221.01 and 1987.0221.02). Donor Ben Rau dated the object to 1968, which is consistent with the form of the company name on the instrument. For Felsenthal company history, see 1977.1141.01 and 1977.1141.02.
References: Deborah J. Warner, “Browse by Maker: Felsenthal,” National Museum of American History Physical Sciences Collection: Navigation , http://americanhistory.si.edu/collections/navigation/maker.cfm?makerid=173; accession file.
Location
Currently not on view
date made
ca 1968
maker
Felsenthal Instrument Co.
ID Number
1977.1141.41
catalog number
336425
accession number
1977.1141

Hemmi Duplex Slide Rule Retailed by Post (Versalog 1460)

The Frederick Post Company, a 20th-century manufacturer and retailer of scientific instruments based in Chicago, did not make its own slide rules. From 1932, its exclusive supplier of linear slide rules was Hemmi, a Japanese firm.
Description
The Frederick Post Company, a 20th-century manufacturer and retailer of scientific instruments based in Chicago, did not make its own slide rules. From 1932, its exclusive supplier of linear slide rules was Hemmi, a Japanese firm. Hemmi was known for using a large-diameter variety of bamboo grown in Kagoshima Prefecture on the island of Kyushu. Company founder Jiro Hemmi (1878–1953) patented this innovation in several nations, including the United States in 1920.
While Post usually sold standard Hemmi models, around 1951 Hemmi created two ten-inch slide rules for Post, which sold in the United States as the model 1450 Versatrig and model 1460 Versalog. The Versalog was especially popular, selling several hundred thousand copies.
This example is bamboo, coated on all sides (except the ends) with white celluloid. The rule is held together with metal posts, one of which is engraved on the front: Wm. Krutz. The glass indicator has a metal frame with plastic sides. One side is marked: HEMMI JAPAN. The other side bears a Post logo in red, which has largely been rubbed away. The red Post logo and the serial number 015836 appear on the right front of the slide. The serial number indicates the rule was manufactured in 1959. This is confirmed by the date code JI on the bottom edge of the rule, which corresponds to a manufacturing date of September 1959.
The top edge of the rule is marked: CAT. NO. 1460; VERSALOG; FREDERICK POST CO.; HEMMI BAMBOO – JAPAN. The front of the base has LL0, LL/0, K, DF, D, R1, R2, AND L scales. The front of the slide bears CF, CIF, CI, and C scales. The LL/0, CIF, and CI scales are numbered in red. The back of the base has LL/1, LL/2, LL/3, D, LL3, LL2, AND LL1 scales. The back of the slide has T, Sec T and ST, Cos and S, and C scales. The LL/1, LL/2, LL/3, T, and Sec T scales are numbered in red. All the other scales are navy.
The rule fits into a black Fabrikoid case with a leather flap (stamped POST). The case could be hung from the user's belt, and it is labeled: W. K. KRUTZ. The case is stored in a red, white, and black cardboard box, along with a guarantee from Post and a ruler-sized white plastic set of conversion tables, copyrighted in 1950 by the Eugene Dietzgen Co., another prominent slide rule manufacturer. The rule also arrived with an instruction booklet, 1978.0800.02.
References: Jiro Hemmi, "Slide-Rule" (U.S. Patent 1,329,902 issued February 3, 1920); Walter Shawlee II, Ted Hume, and Paul Ross, "The Post Slide Rule Archive," Sphere Research Corporation, http://www.sphere.bc.ca/test/post.html; Bob Otnes, "Notes on Frederick Post Slide Rules," Journal of the Oughtred Society 7, no. 1 (1998): 7–10; Paul Ross and Ted Hume, "Slide Rules of the Frederick Post Company," Journal of the Oughtred Society 9, no. 2 (2000): 37–46; Ted Hume, "The Popular Post Versalog Slide Rule," Journal of the Oughtred Society 15, no. 1 (2006): 53–55; William Lise, "Japanese Slide Rules," 19 August 2004, accessed via Internet Archive Wayback Machine; E. I. Fiesenheiser, The Versalog Slide Rule: An Instruction Manual (Chicago: The Frederick Post Company, 1951).
Location
Currently not on view
date made
1959
maker
SUN HEMMI JAPAN CF
inventor
Frederick Post Co.
ID Number
1978.0800.01
catalog number
336682
accession number
1978.0800

Japanese Artillery Simplex Slide Rule

This ten-inch, one-sided Japanese brass linear slide rule has a (broken) glass indicator in a brass frame. On the top and bottom of the base and the top edge of one side of the slide are logarithmic scales that are identically marked and run from 10 to 10,000.
Description
This ten-inch, one-sided Japanese brass linear slide rule has a (broken) glass indicator in a brass frame. On the top and bottom of the base and the top edge of one side of the slide are logarithmic scales that are identically marked and run from 10 to 10,000. These are labeled with a Japanese character that signifies kyori (distance). The lowest scale on this side of the slide is also logarithmic, but has 1/10 the values of the other 3 scales (except at the end, where it reads 800 instead of 1,000). This scale is for reading maps drawn to 1/6,400 scale.
In the center of this side of the slide is a scale that runs from .01 to 45. It is labeled on the left with 1/16, for map reading conversions, and is labeled on the right with the character for seisetsu (tangent). The reverse side of the slide has two logarithmically divided scales, divided in the same way. One runs from 1 up to 1,600. The other runs from 3,199 down to 1,600. Both of these scales are labeled with the Japanese character for seigen (sine). The upper edge of the instrument is beveled and has a scale of 28 centimeters, divided to millimeters. The flat front of the instrument is also divided in a scale of equal parts. This scale runs from 1 to 138.
The rule fits in a sturdy brown leather case with a buckle clasp. For a similar object, see "Japanese Gun Laying Slide Rule, 1920–1929" in the Powerhouse Museum, http://www.powerhousemuseum.com/collection/database/?irn=384855. According to the donor, Robert L. Klinger, this instrument was recovered from an artillery dump at Asahigawa in Hokkaido, Japan in October of 1945. Klinger went on to work for the Smithsonian Institution.
Location
Currently not on view
date made
before 1945
ID Number
1978.2289.01
catalog number
1978.2289.01
accession number
1978.2289
catalog number
336874

Pickett & Eckel Model 2 Deci Log Log Duplex Slide Rule

This 10-inch duplex slide rule is made from a magnesium alloy coated with white celluloid. It has a flat glass indicator with metal sides and stainless steel end posts. One screw on the back bottom side is missing.
Description
This 10-inch duplex slide rule is made from a magnesium alloy coated with white celluloid. It has a flat glass indicator with metal sides and stainless steel end posts. One screw on the back bottom side is missing. The top side is engraved with a serial number: CO24920.
The front of the rule has nine D scales, four also labeled 1/N, one also labeled Co, and four also labeled N. The two groups of four scales are extended and folded, so that for reading off logarithms, the rule is the equivalent of a rule 80" long. The slide has CF, CI, and C scales.
The slide has several markings above the scales. The first marking reads: INTERNATIONAL (/) COPYRIGHT 1947 (/) U.S.A. COPYRIGHT 1947 (/) R. C. PICKETT, A. F. ECKEL (/) CHICAGO, U.S.A. Second, there is a table for Digits or Zero for Sine and Tangent and a table for the number of digits in a result found on the C scale. Third, a logo inside an oval reads: DECI• (/) LOG LOG (/) Trade Mark. Fourth is another table for whether a result has zeroes or digits in results for squares, cubes, and roots. The fifth marking reads: THE NUMBER OF ZEROS IS (/) ONE LESS THAN THE ABSO- (/) LUTE VALUE OF THE NEGA- (/) TIVE CHARACTERISTIC. (/) EXAMPLE: 10-5 = .00001. The sixth marking reads: THE NUMBER OF DIGITS IS (/) ONE GREATER THAN THE (/) POSITIVE CHARACTERISTIC. (/) EXAMPLE: 105 = 100,000. Finally, a mark at the right end of the slide reads: PATENTS PENDING (/) MADE IN U.S.A. (/) PICKETT & ECKEL, INC. (/) CHICAGO 3, U.S.A. (/) MODEL 2.
The back of the rule has three cube root scales, an L scale, a D scale, and two square root scales. The scales for roots are folded, so that the rule is the equivalent of 60" in length for cube roots and 20" in length for square roots. The slide has two T scales and ST, S, CI, and C scales. The left side of the slide is marked: INTERNATIONAL (/) COPYRIGHT 1945 (/) U.S.A. COPYRIGHT 1945 (/) R.C. PICKETT, A. F. ECKEL (/) CHICAGO, U.S.A.
Arthur Frederick Eckel (1894–1960) and Roswell Colvert Pickett (1892–1969) partnered in Chicago in 1943 to manufacture slide rules. By 1946, they had transitioned from paper slide rules to magnesium, and Pickett established a branch of the company in Alhambra, Calif. In 1947, Maurice L. Hartung, a University of Chicago professor who helped Pickett & Eckel market their products to schools, described the Model 2 in How to Use the Deci-Log Log Slide Rule (Chicago: Pickett & Eckel, 1947). A copy of this pamphlet is 1979.0601.04. Eckel received four of the patents mentioned as "pending" on the object in 1948 and 1949. He left the company around that time, and his name was removed from slide rules by 1950. Thus, this example was probably made between 1946 and 1950.
Indeed, the donor, Frank M. Graves, reported that he used this rule as a college student. He received a Bachelor of Science degree in chemistry from Syracuse University in 1949.
The rule fits in a brown leather case marked on the flap with "Pickett" in script over a triangular logo. A belt loop on the back of the case is marked: SADDLE (/) LEATHER. The logo was used by the company from 1950 to 1958, so the case may be a replacement. The style of the belt loop, though, differs from the ring construction depicted in Pickett's 1953 catalog. In 1953, Model 2 and its case sold for $21.35.
References: Arthur F. Eckel, "Decimal Point Locator for Slide Rules" (U.S. Patent 2,446,696 issued August 10, 1948), "Calculator and Decimal Point Locator (U.S. Patent 2,466,883 issued April 12, 1949), "Slide Rule," (U.S. Patent 2,466,983 issued April 12, 1949), "Interchangeable Scale for Slide Rules" (U.S. Patent 2,491,650 issued December 20, 1949); Pickett All-Metal Slide Rules and "Retail Price List-Catalog," (Chicago: Pickett & Eckel, February 1, 1953); International Slide Rule Museum, "Pickett All-Metal Slide Rules," http://sliderulemuseum.com/SR_Dates.htm#Pickett; Accession File.
Location
Currently not on view
date made
1946-1950
maker
Pickett & Eckel, Incorporated
ID Number
1979.0601.02
catalog number
1979.0601.02
accession number
1979.0601

Gilson Binary Circular Slide Rule

This two-sided aluminum circular slide rule is coated with white celluloid enamel. The front has two interlocking yellow-green plastic arms, pivoted at the center with a metal nut and bolt with metal washers on both front and back. The back has one rotating arm.
Description
This two-sided aluminum circular slide rule is coated with white celluloid enamel. The front has two interlocking yellow-green plastic arms, pivoted at the center with a metal nut and bolt with metal washers on both front and back. The back has one rotating arm. Thirteen circles of scales are on the front, including C (for multiplication, division, and proportion), CI (C inverted), A (squares), K (cubes), logarithms, a spiral log-log scale (marked from 1.0015 to 1,000,000), two binary scales for adding and subtracting fractions, a scale of drill sizes, a scale of thread sizes, and millimeters. The front is marked near the center: THE BINARY SLIDE RULE (/) MADE IN U.S.A. (/) COPYRIGHTED 1940.
Three concentric circles forming a scale of degrees, sines, and tangents are on the back. Inside this scale is a chart for decimal equivalents of fractions. The back is marked: COPYRIGHTED (/) 1931 (/) GILSON SLIDE RULE CO. (/) STUART, FLA. The sets of scales are almost the same as those on 1998.0119.01 and 1989.0032.01, which are both Gilson Midget circular slide rules, but the scale of thread sizes is in United States Form instead of United States Standard. Because it does not have alternating yellow and white stripes, this rule is unusual for a Gilson Binary slide rule. There is a case for this rule.
References: Sphere Research Corporation, "Gilson Binary/Atlas Circular Slide Rule Operating Information," http://www.sphere.bc.ca/test/circular-man2.html; Clippings Scrapbook, page 82, Cummings Library, Palm City, Fla.
Location
Currently not on view
date made
after 1940
maker
Gilson Slide Rule Company
ID Number
1979.0816.01
catalog number
1979.0816.01
accession number
1979.0816

Macbeth Daylighting Circular Slide Chart

In the first half of the 20th century, electric lighting became commonplace in American stores, factories, and homes.
Description
In the first half of the 20th century, electric lighting became commonplace in American stores, factories, and homes. Firms such as Macbeth Daylighting Company of New York City and Corning Glassware of Corning, N.Y., developed special glass filters that transmitted incandescent light with optical properties similar to those of natural light. Macbeth distributed this white paper circular slide chart, which allowed the user to compare the efficiency and color temperature of Macbeth Whiterlite filters and Corning Daylite filters.
The device is marked: MACBETH DAYLIGHTING CO., Inc. (/) 227–239 West 17th Street (/) New York. It probably dates from between 1920 and 1950. A tan paper envelope is also marked with the company's address.
Location
Currently not on view
date made
1920-1950
maker
Macbeth-Evans Glass Company
ID Number
1979.3074.01
nonaccession number
1979.3074
catalog number
1979.3074.01

Cenco Gas Volume Reduction Circular Slide Rule

This yellow paper circular rule consists of two discs, one with a protruding tab for rotating the disc, held together with a metal grommet. The device reduces the observed volume of a gas to the corresponding volume under standard conditions (0°C, 760 mm pressure).
Description
This yellow paper circular rule consists of two discs, one with a protruding tab for rotating the disc, held together with a metal grommet. The device reduces the observed volume of a gas to the corresponding volume under standard conditions (0°C, 760 mm pressure). Scales for temperatures from 10 degrees to 35 degrees centigrade and for pressures from 700 to 790 mm run along the lower edge of the rule. Setting the device for an observed temperature and pressure reveals a volume factor and the logarithm of the volume factor in the lower interior of the instrument. The factor is multiplied by the observed volume on the scale along the upper edge of the instrument to arrive at the reduced volume.
The instrument is marked: CentralScientificCo. (/) CENCO (/) CHICAGO U.S.A. (/) GAS VOLUME REDUCTION CHART. It is also marked: Copyrighted 1921, by Central Scientific Co. An advertisement for the "new rotary CENCO hyvac pump," available from Central Scientific's Bulletin No. 92, appears on the back of the device. For another instrument made by Central Scientific Co., see 1982.0147.02.
The front of the instrument indicates that Prof. E. M. Jones of Adrian College in Adrian, Mich., proposed its design. Jones also wrote "Laboratory Versus Recitation," School Science and Mathematics 8 (1923): 749–759. In 1920, he was appointed to the city of Adrian's first water board.
Reference: "Adrian H2O: Over One Hundred Years," http://www.ci.adrian.mi.us/Services/Utilities/History.aspx.
Location
Currently not on view
date made
after 1921
maker
Central Scientific Company
ID Number
1979.3074.02
nonaccession number
1979.3074
catalog number
1979.3074.02

Perrygraf Ohm's Law Calculator Slide Rule for Ohmite

This rectangular yellow, orange, black, and white rule consists of a paper envelope holding a paper slide, held together with metal rivets. The Ohmite Manufacturing Company of Chicago commissioned it from the Perrygraf (or Perry Graf) Corporation of Maywood, Ill.Lester E.
Description
This rectangular yellow, orange, black, and white rule consists of a paper envelope holding a paper slide, held together with metal rivets. The Ohmite Manufacturing Company of Chicago commissioned it from the Perrygraf (or Perry Graf) Corporation of Maywood, Ill.
Lester E. Perry (1901–1991), a machinery inspector in Cook County, Ill., founded Perrygraf in 1934. He and his associates, including his relative Oscar Perry, designed and manufactured special-purpose "slide charts." By 1960, the firm had a branch in California and a plant in Puerto Rico. In 1968 the firm was sold to Nashua Corporation, and operations in Illinois ceased. Some former employees started their own slide chart companies. James E. Johnson, the former plant manager, established American Slide Chart in 1971. This Wheaton, Ill., firm became sufficiently successful to purchase Perrygraf in 1988. Another former Perrygraf employee and engineer established Datalizer Slide Charts of Addison, Ill. Both American Slide Chart/Perrygraf and Datalizer Slide Charts remain in business as of 2012.
The Ohmite Manufacturing Company, established in 1925, sold rheostats, fixed resistors, and adjustable resistors. Its Ohm's Law Calculator had scales that allowed the user to find ohms, volts, amperes, and watts, given any two of those measures. It also had a chart for finding the stock number of desired parts. This example was copyrighted in 1941 and sold for ten cents. The name of the donor is stamped on both sides. An electronic version of the calculator may be found on the company's website.
References: George Melloan, "Pocket Slide Charts Aid Engineers, Help Sell Steel, Lipstick," Wall Street Journal, September 4, 1953, 1; Display Ad, Los Angeles Times, November 8, 1960, 22; "About Perrygraf," http://www.quinndesign.com/profweb/perrygraf/; "About Us," American Slide Chart/Perrygraf, http://www.americanslidechart.com/aboutus.html; "Slide Chart Specialists," Datalizer Slide Charts, http://www.datalizer.com/about-us/; "Ohmite History," http://www.ohmite.com/history.php.
Location
Currently not on view
date made
1941
maker
Perry Graf Corporation
ID Number
1979.3074.03
nonaccession number
1979.3074
catalog number
1979.3074.03

D-K Statistical Slide Rule

This is one of several slide rules designed for use in psychology. It has a white plastic envelope that holds a paper slide.
Description
This is one of several slide rules designed for use in psychology. It has a white plastic envelope that holds a paper slide. The upper part of the envelope has scales labeled A (a 23-centimeter ruler, divided to millimeters), N (number of cases), PE (probable error, running from 1 to 10), sigma (running from 1 sigma to 10 sigma), and c (probability that an event happened by chance). The top part of the slide has scales labeled r (running from 0.97 down to 0.00, divided logarithmically) and B (logarithmically divided from 0.05 to 0.20).
The lower part of the envelope has scales labeled sigma (standard deviation) and D (a standard slide rule logarithmic scale for multiplication, running from 10 to 140). The lower part of the slide has scales labeled sigma1.2, sigmaM (standard error of measurement), and C (divided logarithmically and running from 10 to 140). The center of the slide has the line graph r1/2 /III to r1I. The back of the envelope has five more line graphs.
Instructions are provided on the back of the slide and on a leaflet received with the rule. The lower left corner of the envelope is marked: Designed by Jack W. Dunlap and Albert K. Kurtz. The lower right corner is marked: Copyright 1933 by The Psychological Corporation. James McKeen Cattell, Robert Sessions Woodworth, and Edward Lee Thorndike founded the Psychological Corporation in New York City in 1921 to market psychological tests and educational materials. Jack W. Dunlap (1902–1977) and Albert Kenneth Kurtz (1904–1992) were academic psychologists interested in graphic computation charts. They copyrighted the D-K Statistical Slide Rule again in 1938, after which it was sold as a duplex wooden rule. After World War II, Dunlap went into industrial psychology.
References: advertisement, Science 79, no. 2041 (February 9, 1934), back matter, 7; Library of Congress Copyright Office, Catalog of Copyright Entries: Part 1, Books, Group 2, Pamphlets, Etc., n.s. 31 (1935): 24; Jack W. Dunlap and Albert K. Kurtz, Handbook of Statistical Nomographs, Tables, and Formulas (Yonkers-on-Hudson, N.Y.: World Book Company, 1932); Albert K. Kurtz, "Obituary: Jack W. Dunlap," American Psychologist 34, no. 6 (June 1979): 538; J. McKeen Cattell, "The Psychological Corporation," Annals of the American Academy of Political and Social Science 110 (November 1923): 165–171.
Location
Currently not on view
date made
1933
publisher
Psychological Corporation
ID Number
1979.3074.04
nonaccession number
1979.3074
catalog number
1979.3074.04

Pickett N3-T Duplex Slide Rule

This aluminum duplex slide rule is coated with "traditional" white plastic. The indicator is flat and made from nylon (hence the "N" in the model number). The front of the rule has two square root scales; K, A, B, ST, S, T, CI, C, D, and DI scales; and three cube root scales.
Description
This aluminum duplex slide rule is coated with "traditional" white plastic. The indicator is flat and made from nylon (hence the "N" in the model number). The front of the rule has two square root scales; K, A, B, ST, S, T, CI, C, D, and DI scales; and three cube root scales. The back of the rule has LL0, LL1, DF, CF, CIF, Ln, CI, C, D, LL2, and LL3 scales. Markings on the rule are described for the nearly identical 2009.0019.01. The rule fits in a burgundy leather case printed with the Pickett logo in gold. A strap and hook on the back attach the case to a belt.
Pickett was making a Model 3 slide rule as early as 1954, but the scales were arranged differently and the front of the slide had the tables found on Model 2. (See 1979.0601.02.) The logo on this instrument was used between 1964 and 1975. The shape of the indicator and the shape of the metal end pieces are consistent with this date range.
For related documentation, see 1980.0097.05 and 1980.0097.06.
References: Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 75–76; Pickett All-Metal Slide Rules, catalog 164-A (Chicago: Pickett & Eckel, Inc., 1954), 11.
Location
Currently not on view
date made
1964-1975
maker
Pickett Industries
ID Number
1980.0097.01
catalog number
1980.0097.01
accession number
1980.0097

Engineering Instruments 250-V Simplex Slide Rule

This ten-inch, one-sided wooden slide rule is coated with white plastic on the front face and both sides of the slide. A, D, and K scales are on the base. B, CI, and C scales are on one side of the slide, with S, L, and T scales on the other side.
Description
This ten-inch, one-sided wooden slide rule is coated with white plastic on the front face and both sides of the slide. A, D, and K scales are on the base. B, CI, and C scales are on one side of the slide, with S, L, and T scales on the other side. The indicator is clear frameless plastic. The top of the base is marked: MADE IN U.S.A. It is also marked: ENGINEERING INSTRUMENTS, INC., PERU, INDIANA. It is also marked: PAT. PEND. The right end of the slide is marked: 250-V. Tables for equivalents and conversions appear on the back of the instrument. The rule fits in a tan paper sleeve—neither the original simulated leather case nor the instruction manual were received with the instrument.
Vivian (Breyer) Lawrence received Lawrence Engineering Service, a manufacturer of slide rules in Peru, Ind., in her divorce from George Lee Lawrence in 1947. Her new husband, Frank Bozarth, was president of the renamed Engineering Instruments, Inc., until the company burned down in 1967. Although the building was insured, Engineering Instruments never rebuilt. This rule probably dates between the late 1950s and 1967. The model number may mean that the rule is 250 mm long with a veneered finish, although the scales are actually about 255 mm. The rule sold for $2.00. Compare to 1983.0042.01.
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.
Location
Currently not on view
date made
ca 1958-1967
maker
Engineering Instruments, Inc.
Lawrence Engineering Service
ID Number
1980.0097.02
accession number
1980.0097
catalog number
1980.0097.02

Four-Sided Gauger's Slide Rule by Cook

This is a twelve-inch, four-sided boxwood slide rule used in England for measuring and taxing barrels of liquid. Each of the four slides has a brass guide at one end, and the various special points on the rules are marked with inset brass pegs.
Description
This is a twelve-inch, four-sided boxwood slide rule used in England for measuring and taxing barrels of liquid. Each of the four slides has a brass guide at one end, and the various special points on the rules are marked with inset brass pegs. On one side, the base has a D scale, logarithmically divided from 1 to 3.2 and from 3.2 to 10. Point 18.789 is marked G, the circular gauge point, for determining the mean diameter of a barrel. Point 46.3 is marked MS, for the side of a square vessel that contains a solid bushel per inch of depth, and point 52.32 is marked MR, for the side of a square vessel that contains a malt bushel per inch of depth. The slide has two identical B scales, logarithmically divided from 1 to 10. Point 277.42 is marked G for the imperial gallon.
On the second side, the base has logarithmic scales that run from 1 to 8 and from 8 to 100. It is labeled SEGT ST (Segments Standing) at the top left and SS at the bottom right. The slide has two identical C scales, logarithmically divided from 1 to 9. This side was used to estimate the volume of a barrel that was standing vertically and partially filled. The back of the slide lists gauge points, divisors, and factors for circles for malt and for gall (another substance used in making alcoholic beverages) in circular and square containers.
On the third side, the base has an A scale, logarithmically divided from 1 to 10, and an MD (Malt Depth) scale that runs logarithmically in the opposite direction from somewhat less than 3 to 20. Point 2219 is marked B, for the number of cubic inches in a bushel under the imperial system of measurement, and point 277.42 is marked G, for the imperial gallon. The slide has two identical C scales, logarithmically divided from 1 to 9. The back of the slide has a scale of inches, a scale labeled SPH[EROI]D, and a scale labeled 2D VAR[IETY]. These scales are for determining the diameters of two different shapes of barrels. Underneath the slide is marked: COOK. MAKER TO THE HONBLE BOARD OF EXCISE. LATE WELLINGTON CROWN COURT SOHO LONDON NO 2950.
On the fourth side, the base has logarithmic scales that run from 0 to 4 and from 4 to 100. It is labeled SEGT LY (Segments Lying) at the top left and SL at the bottom right. The slide has two identical B scales, logarithmically divided from 1 to 9. Underneath the slide, points 3.9 and 99 are connected by a line marked with H.
The use of the Imperial system of units dates this slide rule to after 1824. It is of the style developed by Thomas Everard in 1683 and, at 12 inches, represents one of the two standard "pocket" sizes (the other was 9"). Laban Cook(e) succeeded Alexander Wellington (d. 1825) as a Maker to the English Board of Excise and remained in business until 1834. Compare to the older rule for gauging and ullage (the amount a container is lacking to be full), 319510.
References: D. Baxandall, Catalogue of the Collections in the Science Museum: Mathematics I. Calculating Machines and Instruments (London, 1926), 42; Colin Barnes, "The Customs and Excise Gauging Slide Rule," Journal of the Oughtred Society 4, no. 2 (1995): 53–57; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 72, 245; Gloria Clifton, Dictionary of British Scientific Instrument Makers (London: National Maritime Museum, 1995), 64.
Location
Currently not on view
date made
1825-1834
maker
Cook, Laban
ID Number
1980.0588.04
catalog number
1980.0588.04
accession number
1980.0588

Alco Personal Calculator (Simplex Slide Rule and Adder)

This pocket-sized sheet metal instrument combines a one-sided linear slide rule, an adder, and a rule. The sliding bar adder on the front has six bars. The upper parts are for addition, and the lower parts are for subtraction. Round windows in the middle show the result.
Description
This pocket-sized sheet metal instrument combines a one-sided linear slide rule, an adder, and a rule. The sliding bar adder on the front has six bars. The upper parts are for addition, and the lower parts are for subtraction. Round windows in the middle show the result. A metal stylus moves the bars, and there is a zeroing bar at the top. The adder is marked: ALCO (/) + ADDITION (/) – SUBTRACTION (/) PERSONAL (/) CALCULATOR (/) MADE IN JAPAN. The back of the instrument is a slide rule with A and D scales on the base; B, CI, and C scales on the slide; and a clear plastic frameless indicator. The slide may be removed to reveal a scale of 5.5 inches, divided to 32nds of an inch, and a scale of 14 centimeters, divided to millimeters. The right end of the slide is marked: MADE IN JAPAN. The instrument fits in a clear and blue plastic sleeve.
Metal adders were available from at least the 1920s. Compare 1986.0543.01, 1988.0807.04, 1989.0325.01, 1989.0709.02, and 1994.0208.01. In 1937 Carl Kübler, whose German firm made the famous Addiator adder, filed a U.S. patent application for attaching an adder to a metal slide rule. By the 1950s, an unknown company in Japan made "personal calculators" (such as 1992.0548.01) and sometimes attached slide rules. In 1968 Al Nyman & Son, Inc., of New York, N.Y., took out a trademark for "alco" for drawing compasses and pocket calculators (serial number 72278404). Perhaps the firm distributed this instrument, although the style of "alco" in the trademark does not match the mark on the object. Nyman is known to have sold a Mannheim slide rule under the alco trademark.
References: Carl Kübler, "Means for Mounting an Adding and Subtracting Device on Slide Rules" (U.S. Patent 2,153,089 issued April 4, 1939); David D. McFarland, "Addition and Subtraction With Slide Rules and Allied Instruments, Part I," Journal of the Oughtred Society 12, no. 2 (2003): 27–36; U.S. Patent and Trademark Office, Trademark Electronic Search System.
Location
Currently not on view
date made
1937-ca 1975
ID Number
1981.0922.07
catalog number
1981.0922.07
accession number
1981.0922

Keuffel & Esser 4053-3 Polyphase Mannheim Duplex Slide Rule

This ten-inch one-sided wooden slide rule is coated with white celluloid. The indicator is glass with white plastic edges attached by metal screws. The base has A, D, and K scales.
Description
This ten-inch one-sided wooden slide rule is coated with white celluloid. The indicator is glass with white plastic edges attached by metal screws. The base has A, D, and K scales. The slide has B, CI, and C scales on one side of the slide and S, L, and T scales on the other side. The top and bottom edges are beveled; the top has a simply divided scale 10 inches long and divided to sixteenths of an inch, while the bottom has a simply divided scale 25 centimeters long and divided to millimeters.
The left end of the slide has the model number in red: 4053-3. The right end is marked in red: © (/) K+E. The left end of the back of the slide has a serial number: 169518. Underneath the slide is marked: KEUFFEL & ESSER CO.; MADE IN U.S.A. Engraved directly on the back of the rule are tables of measures labeled: CONVERSION FACTORS. Centered underneath the tables is: KEUFFEL & ESSER CO.
Keuffel & Esser made slide rules of this type from 1909 to 1967. McCoy notes that this version of model 4053-3 (with this model number and the engraved tables) was introduced in 1954. In 1959, the rule sold in a plain case for $13.50. In 1962, model number 4053-3 was changed to 68-1622. The serial number suggests a date closer to the late 1950s than to the early 1960s. Compare to the earlier rule, 1981.0933.05.
References: Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 192; Clark McCoy, "Collection of Pages from K&E Catalogs for the 4053 Family of Slide Rules," http://www.mccoys-kecatalogs.com/KEModels/ke4053family.htm; K+E Catalog, 42nd ed. (New York, 1954), 271; Ed Chamberlain, "Estimating K&E Slide Rule Dates," http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; Eric Marcotte, "The Evolution of a Slide Rule – The K&E 4053-3," http://www.sliderule.ca/4053.htm.
Location
Currently not on view
date made
1954-1962
maker
Keuffel & Esser Co.
ID Number
1981.0922.08
accession number
1981.0922
catalog number
1981.0922.08

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 telescoping rule is ten inches long when extended and equivalent to a rectangular 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.
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 engraved: MADE IN (/) Y9481 (/) ENGLAND.
Otis Carter Formby King invented this form of slide rule in 1921, and Carbic Limited of London, England, manufactured it until 1972. The serial number, Y9481, suggests a date about 1965–1969 for this example. A collector of computing devices donated it to the Smithsonian.
See also 1987.0788.01 and 1989.3049.02. For documentation, see 1981.0922.10 and 1981.0922.11.
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
ca 1965-1968
maker
Carbic Limited
ID Number
1981.0922.09
catalog number
1981.0922.09
accession number
1981.0922

Pickett 101-C Circular Slide Rule

This yellow aluminum circular slide rule has three clear plastic indicators, one blank. The other indicator on the front is marked in red to denote the C, CI, A, AF, L, FA, LL2, LL1, DS, DT, and M scales.
Description
This yellow aluminum circular slide rule has three clear plastic indicators, one blank. The other indicator on the front is marked in red to denote the C, CI, A, AF, L, FA, LL2, LL1, DS, DT, and M scales. The indicator on the back is marked in red to denote the C, S,ST, and T scales. A ring of numbers under the scales on the back permits conversions from fractions to decimals.
The center of the front is marked: CIRCULAR SLIDE RULE – dial rule (/) PICKETT. The center of the back is marked: dial rule (/) NO 101-C. A triangular Pickett logo, of the form used between 1950 and 1958, appears at the bottom of the center; CHICAGO is printed below the logo.
Pickett & Eckel, a slide rule manufacturer based in Chicago and Alhambra, Calif., distributed a small booklet with this instrument, one of the few circular slide rules sold by the company and possibly the only circular model it manufactured. Maurice L. Hartung, a University of Chicago mathematics professor associated with the company, wrote the instruction manual (1981.0922.13). The booklet is copyrighted 1957, and the logo on this copy was used by the company between 1958 and 1962. Thus, this slide rule dates to about 1958.
References: Rodger Shepherd, "Pickett Metal Slide Rules," Journal of the Oughtred Society 1, no. 1 (1992): 5–8; Walter Shawlee, "Information About Pickett Slide Rules," Sphere Research Slide Rule Site, http://www.sphere.bc.ca/test/pickett.html.
Location
Currently not on view
date made
ca 1958
maker
Pickett & Eckel, Incorporated
ID Number
1981.0922.12
catalog number
1981.0922.12
accession number
1981.0922

Ole Jorgensen Creative Workshop Universal Circle Slide Rule

This black plastic instrument is shaped like a pencil cup. A fixed scale labeled x3 is near the rim, with four rotating parallel bands below it. The first band is white and has x and x2 scales. The second band is gray and has two x scales.
Description
This black plastic instrument is shaped like a pencil cup. A fixed scale labeled x3 is near the rim, with four rotating parallel bands below it. The first band is white and has x and x2 scales. The second band is gray and has two x scales. The third band is white and also has two x scales. The fourth band is gray and has an x2 scale. The bands do not move very easily. The scales labeled x are logarithmically divided and run from 1 to 9.5 once (they are similar to the C and D scales on other slide rules). The scales labeled x2 are divided logarithmically from 1 to 10 and then from 1 to 9, and are similar to the A and B scales on other slide rules. The scale labeled x3 is divided logarithmically from 1 to 10 three times and resembles a K scale on other slide rules. There is no indicator.
The rim of the object is marked in white: UNIVERSAL CIRCLE SLIDE RULE. The bottom of the instrument is marked: ORIGINAL DESIGN BY OLE JORGENSEN CREATIVE WORKSHOP INC. COPENHAGEN DENMARK (/) © OLE JORGENSEN 1970 PAT. PEND. MADE IN DENMARK. Ole Jørgensen's Creative Workshop made a variety of plastic items in the early 1970s, including slide rule pencil cups and desk calendars. Some were marked as promotional items for other companies. It is not known whether Jørgensen ever received a patent for this device. By 1972, the company's production shifted from Denmark to Hong Kong. The company was dissolved around 1980.
References: Chris Gillings, "Universal Circle Slide Rule," http://chris.gillings.com/collect/slide/ucsr.html; "Universal Circle slide rule, 1970," Powerhouse Museum Collections Database, http://www.powerhousemuseum.com/collection/database/?irn=382846; "Historical Photos of People with Slide Rules and Related Ephemera," International Slide Rule Museum, http://sliderulemuseum.com/SR_Ephemera.htm; The London Gazette (24 January 1980), 1169, http://www.london-gazette.co.uk/issues/48076/pages/1169/page.pdf; completed online auction records.
Location
Currently not on view
date made
ca 1970
maker
Creative Workshop, Inc.
ID Number
1981.0922.14
catalog number
1981.0922.14
accession number
1981.0922

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