Science & Mathematics - Overview
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.
"Science & Mathematics - Overview" showing 59 items.
Page 1 of 6
Keuffel & Esser 4078 Duplex Slide Rule
- 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
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 4053-3 Polyphase Mannheim Duplex Slide Rule
- 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
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 4092 Log Log Duplex Slide Rule
- Description
- This ten-inch mahogany duplex slide rule is faced with yellowed white celluloid and held together with corroded L-shaped end pieces. On one side, the base has A and D scales, with B, S, and C scales on the slide. The left end of the slide is marked in red: < 4092 >. The bottom of the base is marked in red: KEUFFEL & ESSER CO. N.Y.; PAT. JUNE 5. '00 DEC. 22. '08. On the other side, the base has LL1, LL2, LL3, D, and L scales, with C, T, and CI scales on the base. The indicator is frameless glass with plastic edges fastened with screws. One edge is marked: K&E.CO.N.Y. (/) PAT.8.17.15.
- Keuffel & Esser of New York offered model 4092 from about 1909 to 1921. The frameless glass indicator was introduced in 1915. The rule sold for $8.00 from 1909 through 1915 and for $12.50 in 1921. This example fits in a cardboard case covered with black leather and marked: KEUFFEL & ESSER Co. (/) LOG. LOG. (/) SLIDE RULE. For instructions, see 1981.0993.02. Later examples of K&E Log Log slide rules in the collections include 1984.1068.02, MA*318479, 1990.0687.01, 1986.0790.03, and 1987.0085.01.
- The donor, William J. Ellenberger (1908–2008), studied electrical and mechanical engineering at The George Washington University between 1925 and 1934. He then worked for the Potomac Electric Power Company and the National Bureau of Standards. During World War II, he served in the U.S. Army Signal Corps. He was a civilian construction management engineer for the army from 1954 to 1968, when he became a private consultant.
- References: Catalogue of Keuffel & Esser Co., 33rd ed. (New York, 1909), 312; Catalogue of Keuffel & Esser Co., 35th ed. (New York, 1915), 304; Catalogue of Keuffel & Esser Co., 36th ed. (New York, 1921), 240; "The GW Engineering Hall of Fame 2006 Inductees," http://www.weas.gwu.edu/ifaf/hall_of_fame_inductees_2006.php.
- Location
- Currently not on view
- Currently not on view
- date made
- 1915-1921
- maker
- Keuffel & Esser Co.
- ID Number
- 1981.0933.01
- catalog number
- 1981.0933.01
- accession number
- 1981.0933
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 4088-3 Polyphase Duplex Slide Rule
- Description
- This ten-inch mahogany duplex linear slide rule is coated with white celluloid and held together with L-shaped metal end pieces. The front of the base has DF and D scales, with CF, CIF, and C scales on the slide. The right end of the slide is marked in red: < 4088-3 >. The bottom of the base is marked in red: PAT. JUNE 5. '00 DEC.22.'08 KEUFFEL & ESSER CO. N.Y. MADE IN U.S.A. The owner's name is scratched on the slide and on the base: ELLENBERGER.
- The back of the base has K, A, D, and L scales, with B, S, T, and CI scales on the slide. A serial number is at the left end of the slide and on the front edge: 161313. The indicator is frameless glass with white plastic edges and metal screws. One edge is marked: K&E.CO.N.Y. (/) PAT.8.17.15. A cardboard case covered with blue leather is not original to this object and is marked: MICRONTA (/) Made in Germany. It also has an owner's label: Wm. J. Ellenberger.
- Keuffel & Esser Company of New York added a B scale to model 4088-3 in 1922. The indicator was modified in 1936. The serial number suggests a manufacturing date around 1927. Between 1922 and 1936, model 4088-3 sold in a box for $8.50. For instructions, see 1981.0933.04 and 1981.0933.06. Compare this example to MA*318476, MA*318480, and MA*321778.
- William J. Ellenberger (1908–2008) was born in Nashville, Tenn. He enrolled in The George Washington University in 1925, earning BS degrees in electrical engineering (1930) and mechanical engineering (1934). It seems likely that Ellenberger acquired and used this slide rule while he studied at GWU. He went on to work for the Potomac Electric Power Company (PEPCO), the National Bureau of Standards, and the U.S. Army.
- References: Catalogue of Keuffel & Esser Co., 36th ed. (New York, 1921), 239; Keuffel & Esser Co., Slide Rules and Calculating Instruments (New York, 1922), 8–9; Catalogue of Keuffel & Esser Co., 38th ed. (New York, 1936), 314–315; Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; accession file.
- Location
- Currently not on view
- Currently not on view
- date made
- 1922-1936
- maker
- Keuffel & Esser Co.
- ID Number
- 1981.0933.03
- catalog number
- 1981.0933.03
- accession number
- 1981.0933
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser N4053-3 Polyphase Mannheim Simplex Slide Rule
- Description
- This ten-inch one-sided mahogany slide rule is coated with white celluloid. The top is beveled and bears a scale of nine inches whose ends may have broken off. The base has A, D, and K scales. The slide has B, CI, and C scales on one side and S, L, and T scales on the other side. The indicator is glass with plastic edges held together with metal screws. The top plastic edge is broken. The front edge of the rule has a scale of 25 centimeters. A paper table of equivalents and slide rule settings, based on U. S. Bureau of Standards Circular No. 47, is pasted to the back of the rule. Compare the table to 1999.0254.01.
- The top of the base is marked in red: PAT. JUNE 5, 1900; KEUFFEL & ESSER CO. N.Y.; MADE IN U.S.A. The right end of the slide is marked in red: < N4053-3 >. The left end of the other side of the slide and the scale of centimeters have the serial number: 350305. The top of the base and under the slide are scratched with the initials: PML. The bottom plastic edge of the indicator is marked: PATENT 2,086,502, with K&E CO. N.Y., on the back of the edge.
- Keuffel & Esser of New York sold this slide rule as model N4053-3 from 1925 through 1953. Illustrations in K&E catalogs include the patent date of June 5, 1900, from 1925 through 1934. The serial number suggests the rule was made closer to 1934. However, the patent on the indicator was issued in 1937, suggesting that this part was replaced after the rule was purchased. Compare to 1981.0922.08.
- William J. Ellenberger (1908–2008) donated this object. He studied electrical and mechanical engineering at The George Washington University between 1925 and 1934. He then worked for the Potomac Electric Power Company and the National Bureau of Standards. During World War II, he served in the U.S. Army Signal Corps. He was a civilian construction management engineer for the army from 1954 to 1968, when he became a private consultant.
- References: Adolf W. Keuffel, "Runner for Slide Rules" (U.S. Patent 2,086,502 issued July 6, 1937); Clark McCoy, "Collection of Pages from K&E Catalogs for the 4053 Family of Slide Rules," http://www.mccoys-kecatalogs.com/KEModels/ke4053family.htm; Ed Chamberlain, "Estimating K&E Slide Rule Dates," http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; Wayne E. Feely, "K & E Slide Rules," The Chronicle of the Early American Industries Association 49, no. 5 (June 1996): 50–52; "The GW Engineering Hall of Fame 2006 Inductees," http://www.weas.gwu.edu/ifaf/hall_of_fame_inductees_2006.php.
- Location
- Currently not on view
- Currently not on view
- date made
- 1925-1934
- maker
- Keuffel & Esser Co.
- ID Number
- 1981.0933.05
- catalog number
- 1981.0933.05
- accession number
- 1981.0933
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 4055 Favorite Simplex Slide Rule
- Description
- This ten-inch mahogany linear slide rule is coated with white celluloid on the front and both sides of the slide. The base has A and D scales. The slide has B and C scales on one side and S, L, and T scales on the other. A paper table of equivalents and slide rule settings, based on U. S. Bureau of Standards Circular No. 47, is pasted to the back of the rule. See also 2001.0117.01. According to Eric Marcotte, this circular was in force from 1914 to 1936. Keuffel & Esser included it on slide rules from the 1920s to the 1950s.
- The indicator is glass with a plastic frame, of the style used by Keuffel & Esser between 1915 and 1937, based on the patent indicated by the mark on the top edge of the frame: K&E.CO.N.Y. (/) PAT.8.17.15. The top of the base is marked in red: PAT. JUNE 5, 1900; KEUFFEL & ESSER CO. N.Y.; MADE IN U.S.A. For more on this patent, see MA*322761. Four expressions have been scratched into the front of the slide: x = A + B; ÷ = A – B; x – 1; ÷ + 1. The model number is printed at the right end in red: < 4055 >. The left end of the back of the slide and the front left corner of the base are marked with a serial number: 190673.
- The rule is in a cardboard case covered with black morocco leather and heavily taped. It is marked: KEUFFEL & ESSER (/) FAVORITE (/) SLIDE RULE (/) 4055. It is also marked on the tape near one end: E. HELLER (/) ΣΦΕ. On the other side of that end, it is marked on the tape: PROPERTY OF (/) PETER (/) HELLER. K&E sold model 4055 from 1927 to 1943; the serial number suggests a date closer to 1927, when the instrument sold for $4.00. One owner of this slide rule was the mechanical engineer Edward Lincoln Heller (1912–2007), who received a BSfrom Lehigh University in 1934 and an MBA from Harvard University in 1939. It seems likely that he used the slide rule as a college student.
- References: Willie L. E. Keuffel, "Slide-Rule" (U.S. Patent 651,142 issued June 5, 1900); Willie L. E. Keuffel, "Slide-Rule Runner" (U.S. Patent 1,150,771 issued August 17, 1915); Eric Marcotte, "The Evolution of a Slide Rule – The K&E 4053-3," http://www.sliderule.ca/4053.htm; Clark McCoy, "Collection of Pages from K&E Catalogs for the 4055 Family," http://www.mccoys-kecatalogs.com/KEModels/ke4055family.htm; Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; "Heller, Edward L.," American Men and Women of Science, 12th ed. (New York: J. Cattell Press, 1972), 2620.
- Location
- Currently not on view
- Currently not on view
- date made
- 1927-1943
- maker
- Keuffel & Esser Co.
- ID Number
- 1984.1068.01
- catalog number
- 1984.1068.01
- accession number
- 1984.1068
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 4092-3 Log Log Duplex Slide Rule
- 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 MA*322761, MA*318475, and MA*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
- 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
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser N4088-5 Polyphase Duplex Slide Rule
- Description
- This 20-inch mahogany duplex slide rule is coated with white celluloid and held together with L-shaped metal end pieces. The front of the base has DF and D scales, with CF, CIF, and C scales on the slide. The right end of the slide is marked in red: < N4088-5 >. The bottom of the base is marked in red: KEUFFEL & ESSER CO. N.Y.; PAT. JUNE 5. '00 DEC. 22. '08; MADE IN U.S.A. Between the second and third of these marks is scratched: BS37884C.
- The back of the base has K, A, D, and L scales, with B, S, T, and CI scales on the slide. The left end of the slide and the front of the rule are marked with a serial number: 235867. A glass indicator has plastic edges held together with metal screws. One edge is marked: K&E.CO.N.Y. (/) PAT.8.17.15. The rule is in a green cardboard box that also contains a paper slip of instructions for adjusting the rule. The back of the slip has a table of equivalents and abbreviations from U.S. Bureau of Standards Circular No. 47. Compare to the tables pasted on the back of slide rules such as 1984.1068.01, MA*321780, and 1987.1084.01. Keuffel & Esser of New York manufactured and sold model N4088-5 from 1936 to 1938 for $22.00.
- The physicist Philip Krupen (1915–2001) gave this slide rule to the Smithsonian in 1986. He earned a BS from Brooklyn College in 1935, worked on the development of the proximity fuse during and after World War II, received an MS in physics from The George Washington University, and spent a total of 38 years working for the U.S. government before he retired in 1973.
- References: Willie L. E. Keuffel, "Slide-Rule" (U.S. Patent 651,142 issued June 5, 1900); Willie L. E. Keuffel, "Slide-Rule" (U.S. Patent 907,373 issued December 22, 1908); Willie L. E. Keuffel, "Slide-Rule Runner" (U.S. Patent 1,150,771 issued August 17, 1915); Catalogue of Keuffel & Esser Co., 38th ed. (New York, 1936), 314–315; "Price List of K&E Slide Rules," (July 1, 1938), 1; 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
- 1936-1938
- maker
- Keuffel & Esser Co.
- ID Number
- 1986.0790.02
- accession number
- 1986.0790
- catalog number
- 1986.0790.02
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 4081-5 Log Log Decitrig Duplex Slide Rule
- 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
- maker
- Keuffel & Esser Co.
- ID Number
- 1986.0790.03
- accession number
- 1986.0790
- catalog number
- 1986.0790.03
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Keuffel & Esser 68-1210 Log Log Duplex Slide Rule
- Description
- This ten-inch duplex slide rule is made from mahogany coated with white celluloid and is held together with metal end pieces. The indicator is glass with plastic edges held together with metal screws. One side of the base has LLO1, L, K, A, D, DI, and LL1 scales, with B, T, SRT, and S scales on the slide. The left end of both parts of the base is marked: 092, and the left end of the slide is marked: 991092. The other side of the base has LLO2, LLO3, DF, D, LL3, and LL2 scales, with CF, CIF, CI, and C scales on the slide. The right side of the slide is marked: © (/) K+E. This form of the K&E logo dates to 1949.
- The top edge of the rule is marked: PATS. PEND.; MADE IN U.S.A; 68 1210 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. The rule has a green leather case marked on the flap: K+E. Inside the flap is written in ink: Howard (/) Eberstein; Pratt (/) Institute (/) 1965. It seems likely that Howard Ebenstein acquired this slide rule as a student at the Pratt Institute. He went on to a career in public service with the Peace Corps and the District of Columbia Energy Office.
- Keuffel & Esser of New York converted its model numbers to the 68 series in 1962. It advertised the model 68–1210 in its 1962, 1966, 1967, and 1972 catalogs. In 1962, the rule came with a case with a belt loop and a hardcover manual. By 1967, there was an option to purchase the rule with a case without a belt loop and a softcover manual. Thus, this example was probably produced closer to 1965 than to 1962. The serial number is also consistent with this date. For earlier versions of this slide rule, sold as the model 4081, see MA*318482, MA*334387, 1990.0687.01, and 1986.0790.03. For instructions, see 1987.0085.02.
- References: Clark McCoy, ed., "K&E Catalogs and Price Lists for Slide Rules," http://www.mccoys-kecatalogs.com/KEmain.htm; Wayne E. Feely, "K & E Slide Rules," The Chronicle of the Early American Industries Association 49, no. 5 (June 1996): 50–52.
- Location
- Currently not on view
- date made
- 1965
- maker
- Keuffel & Esser Co.
- ID Number
- 1987.0085.01
- accession number
- 1987.0085
- catalog number
- 1987.0085.01
- Data Source
- National Museum of American History, Kenneth E. Behring Center
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