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.

Place: Chicago

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

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

Felsenthal Artillery Protractor

This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point.
Description
This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point. The bottom edge of the protractor is divided by hundreds and marked by five hundreds from 0 to 8,000 yards. A small vernier appears to the left of the scale, and the scale is labeled: 1/20,000.
The interior of the protractor has a semicircular opening with a groove parallel to the origin point. Below the opening is a maker's mark: 16 INCH (/) G. FELSENTHAL & SONS, INC. (/) -CHICAGO-. The letters U.S. are printed above the origin point. Donor Ben Rau, who worked for Felsenthal, dated the object to 1942. The form of the maker's name indicates it was probably manufactured for the U.S. Army in the 1950s.
This protractor is very similar to 1977.1141.11, although the scale for plotting the distance of fired artillery is in yards rather than in meters.
See also 1977.1141.01, 1977.1141.02, 1977.1141.03, 1977.1141.05, 1977.1141.08, 1977.1141.09, 1977.1141.10, 1977.1141.12, 1977.1141.19, 1977.1141.20, 1977.1141.21, 1977.1141.22, 1977.1141.23, 1977.1141.24, 1977.1141.30, and 1977.1141.39.
Location
Currently not on view
date attributed by donor
1942
date made
1950s
maker
G. Felsenthal & Sons, Inc.
ID Number
1977.1141.18
accession number
1977.1141
catalog number
336402

Range Correction Chart, Felsenthal FAS-3

This white plastic chart was designed for the U.S. Army Signal Corps.
Description
This white plastic chart was designed for the U.S. Army Signal Corps. It is a nomogram for finding the range correction in yards of a weapon, by lining up the meteorological correction as a percentage of the range and the range.
On the left is a scale marked “Range Correction in Yds.” On the right is a scale marked “Percentage Meteorological Correction” and on the diagonal between the two is a scale marked “Range in Yds.” According to a label received with the object and stored in the accession file, the object was made in 1945.
The meteorological correction is found from the temperature and wind speed using a related chart called a “sound velocity corrector” (for an example, see 1977.1141.42) .
A mark on the object reads: Range Correction Chart PT-63/TSS-1.
For an explanation of the mathematical theory of this kind of nomogram, see Lipka. For a similar device used for another purpose, see 1985.0636.01.
References:
Joseph Lipka, Graphical and Mechanical Computation. Part I. Alignment Charts, New York: John Wiley & Sons, 1921, pp. 65–
67.
Accession file.
Location
Currently not on view
date made
1945
author
G. Felsenthal & Sons
ID Number
1977.1141.43
catalog number
336427
accession number
1977.1141

Calculating and Measuring Device, Navig-Aider, Felsenthal FDJ-13A

This plastic instrument with a metal pivot combines a straight edge, dividers, a course protractor, and a time-speed and drift computer. Instructions are given on it. The date, maker and model number are taken from the accession file.
Description
This plastic instrument with a metal pivot combines a straight edge, dividers, a course protractor, and a time-speed and drift computer. Instructions are given on it. The date, maker and model number are taken from the accession file. The collections include two examples.
Reference:
Accession file.
Location
Currently not on view
date made
1960
maker
Felsenthal Instrument Co.
ID Number
1977.1141.40
catalog number
336424
accession number
1977.1141

Felsenthal FAE-23A Artillery Protractor

This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point.
Description
This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point. The bottom edge of the protractor is divided by hundreds and marked by thousands from 3,000 to 0. A vernier appears to the right of the scale. The scale is labeled: 1/25,000 METERS. Superimposed on the scale is a second scale, divided by two hundreds and marked (in red) by two thousands from 0 to 6,000. A vernier appears to the left of that scale, which is labeled (in red): 1/50,000 METERS.
The interior of the protractor has a relatively small semicircular opening with a groove parallel to the origin point. Below the opening is a maker's mark: 8 INCH (/) FELSENTHAL INSTRUMENTS CO. (/) CHICAGO (/) FAE-23A. The letters U.S. are printed above the origin point. Donor Ben Rau, who worked for Felsenthal, dated the object to 1951. The form of the signature indicates the protractor was probably manufactured for the U.S. Army in the 1960s.
This protractor is very similar to 1977.1141.11. See also 1977.1141.01, 1977.1141.02, 1977.1141.03, 1977.1141.05, 1977.1141.08, 1977.1141.09, 1977.1141.10, 1977.1141.18, 1977.1141.19, 1977.1141.20, 1977.1141.21, 1977.1141.22, 1977.1141.23, 1977.1141.24, 1977.1141.30, and 1977.1141.39.
Reference: Copyright Office, Library of Congress, "Books and Pamphlets," Catalog of Copyright Entries, 3rd ser., 16, part 1, no. 2 (1964): 1392.
Location
Currently not on view
date attributed by donor
1951
date made
1960s
maker
Felsenthal Instrument Co.
ID Number
1977.1141.12
accession number
1977.1141
catalog number
336396

Felsenthal FAE-8 Artillery Protractor

This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point.
Description
This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point. The bottom edge of the protractor is divided by hundreds and marked by thousands from 7,000 to 0. A vernier appears to the right of the scale. The scale is labeled: 1/25,000. Superimposed on the scale is a second scale, divided by two hundreds and marked (in red) by two thousands from 0 to 14,000. A vernier appears to the left of that scale, which is labeled (in red): 1/50,000 YARDS.
The interior of the protractor has a semicircular opening with a groove parallel to the origin point. Below the opening is a maker's mark: 16 INCH (/) G. FELSENTHAL & SONS, INC. (/) -CHICAGO- (/) FAE-8. The letters U.S. are printed above the origin point. Donor Ben Rau dated the object to 1945, but the form of the signature indicates the protractor may not have been manufactured for the U.S. Army until the 1950s.
This protractor is very similar to 1977.1141.12, although the scale for plotting the distance of fired artillery is in yards rather than in meters. The red ink on this instrument is particularly vibrant. See also 1977.1141.01, 1977.1141.02, 1977.1141.03, 1977.1141.05, 1977.1141.08, 1977.1141.09, 1977.1141.10, 1977.1141.11, 1977.1141.18, 1977.1141.20, 1977.1141.21, 1977.1141.22, 1977.1141.23, 1977.1141.24, 1977.1141.30, and 1977.1141.39.
Reference: 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.
Location
Currently not on view
date attributed by donor
1945
date made
1950s
maker
G. Felsenthal & Sons, Inc.
ID Number
1977.1141.19
accession number
1977.1141
catalog number
336403

Instruction Manual for Pickett & Eckel Log Log Trig Slide Rule

The citation information for this small 32-page booklet is: Maurice L. Hartung, How to Use the 300 Log Log Trig Pocket Slide Rule (Chicago: Pickett & Eckel, Inc., 1949).
Description
The citation information for this small 32-page booklet is: Maurice L. Hartung, How to Use the 300 Log Log Trig Pocket Slide Rule (Chicago: Pickett & Eckel, Inc., 1949). It provides general information on how to use slide rules, including the arithmetical operations, locating the decimal point, combining multiplication and division, using the folded scales, calculating roots, trigonometry, and vectors.
Model 300 was a six-inch, pocket-sized duplex slide rule and is not presently represented in the Smithsonian collections, although 1999.0096.01 is a ten-inch log log trig rule. Hartung was a University of Chicago professor who helped Pickett & Eckel market their products to schools and who wrote several instruction manuals for the company's slide rules. See 1979.0601.02.
Location
Currently not on view
date made
1949
maker
Hartung, Maurice L.
ID Number
1979.0601.03
accession number
1979.0601
catalog number
1979.0601.03

Code Designator Slide Chart - FELSENTHAL FAA-141A

This slide chart is designed to assist in coding United States Air Force forms for inventory control. The envelope is of clear plastic printed in blue, with a white plastic card that slides crosswise.
Description
This slide chart is designed to assist in coding United States Air Force forms for inventory control. The envelope is of clear plastic printed in blue, with a white plastic card that slides crosswise. The sliding card has columns for eight Air Force forms (forms number 158A&B, 158C&D, 813, 814, 815, 158-7, 366J&K, and 366L&M). The numbers in each column indicate the place on the form on which the data is to be entered. For example, in all eight forms spaces 1through15 are for the stock number and spaces 31through 34 are for the organization number. The first 56 spaces are described on the front of the sliding card. The remainder (up to 80) are on the back.
It is possible that the forms described are 80-column punch cards, such as those made by IBM for use with electronic data processing equipment.
A mark on the front of the envelope reads: Code Designator (/) Slide Chart. A mark on the back of the envelope reads: Felsenthal Instruments Co.1963 (/) Chicago 31, Illinois (/) MFR’s PT.NO. FAA-141-A.
Location
Currently not on view
date made
1963
maker
Felsenthal Instruments Co.
ID Number
1977.1141.44
catalog number
336428
accession number
1977.1141

Felsenthal FAE-9 Protractor

This clear plastic rectangular protractor is divided by single degrees and marked by tens from 10° to 170° and from 190° to 350°. Pinholes near the 20° and 60° marks allow for positioning the protractor.
Description
This clear plastic rectangular protractor is divided by single degrees and marked by tens from 10° to 170° and from 190° to 350°. Pinholes near the 20° and 60° marks allow for positioning the protractor. The bottom edge is divided by tenths of an inch and marked by ones from 1" to 5". The interior of the protractor contains three scales of equal parts: 1) divided by hundreds and marked by five hundreds from 0 to 2,500 yards, for a scale of 1/20,000; 2) divided by hundreds and marked by thousands from 0 to 7,000 yards, for a scale of 1/62,500; and 3) divided by hundreds and marked by five hundreds from 0 to 2,000 meters, for a scale of 1/20,000. There are verniers to the left of the first and third scales.
Near the top of the protractor is marked: U.S. 1951. The 1951 is believed to refer to the date of the object. The maker's mark is: G. FELSENTHAL & SONS, INC. (/) PART NO. FAE-9.
This protractor is almost exactly like 1977.1141.09. See also 1977.1141.01, 1977.1141.02, 1977.1141.03, 1977.1141.05, 1977.1141.10, 1977.1141.11, 1977.1141.12, 1977.1141.18, 1977.1141.19, 1977.1141.20, 1977.1141.21, 1977.1141.22, 1977.1141.23, 1977.1141.24, 1977.1141.30, and 1977.1141.39.
Reference: 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.
Location
Currently not on view
date attributed by donor
1951
maker
G. Felsenthal & Sons, Inc.
ID Number
1977.1141.08
accession number
1977.1141
catalog number
336392

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

Dietzgen 932S Excello Dotting Instrument

This 2-1/4" German silver and steel metal drawing instrument consists of a teardrop-shaped plate to which is attached a mechanism that is supposed to hold a larger serrated wheel and a smaller pattern wheel. The mechanism links the wheels to a bar that holds a pen point.
Description
This 2-1/4" German silver and steel metal drawing instrument consists of a teardrop-shaped plate to which is attached a mechanism that is supposed to hold a larger serrated wheel and a smaller pattern wheel. The mechanism links the wheels to a bar that holds a pen point. When the larger wheel is rolled along the edge of a T-square or straight edge, the pen point bounces up and down to make a dotted line that formed part of an engineering drawing.
The larger wheel (5/8" diameter) is marked with one of the trademarks for the Eugene Dietzgen Co., the superimposed letters E and D inside a circle formed by the letters C and o. The six smaller wheels (9/16" diameter) also have this trademark and are numbered from 1 to 6, representing six possible dotting patterns. All the wheels are made of brass. The instrument also has the trademark and is marked: EXCELLO. The arm holding the pen point is marked: DIETZGEN (/) GERMANY. The instrument is in a rectangular wooden bar-lock case covered with black leather and lined with green velvet. The top of the case is marked: DIETZGEN (/) “EXCELLO”. The top is also marked: GERMANY.
This dotting instrument was advertised as model 932S in the 1926 Dietzgen catalog and sold for $5.15. It was part of the Excello product line, Dietzgen's second-highest level of drawing instruments. This object was used in the physics department at Kenyon College. Compare to 1987.0788.02.
Reference: Catalog of Eugene Dietzgen Co., 12th ed. (Chicago, 1926), 57–59, 84.
Location
Currently not on view
date made
ca 1926
distributor
Eugene Dietzgen Company
ID Number
1982.0147.01
accession number
1982.0147
catalog number
1982.0147.01

Psychological Test with Manual, SRA Verbal Form

This document is entitled the Science Research Associates Specimen Set. There are multiple documents contained within a red folder.
Description
This document is entitled the Science Research Associates Specimen Set. There are multiple documents contained within a red folder. Inside the red folder there are three documents: the SRA Verbal Examiner’s Manual, the SRA Verbal Form A (Copyrighted in 1947), and SRA Verbal Form B (Copyrighted 1955). The SRA Verbal Examiner’s Manual was copyrighted in 1947, 1956, and 1967 and is ten pages long. The Verbal Forms were prepared by Thelma Gwinn Thurstone, Ph.D., and L.L. Thurstone, Ph.D. Both of the tests ask 84 different questions.
Location
Currently not on view
date made
1955
author
Thurstone, L. L.
maker
Science Research Assoc. Inc.
author
Thurstone, Thelma G.
ID Number
1979.3064.07
catalog number
1979.3064.07
nonaccession number
1979.3064

Post 3000 Pencil Pointer

This pencil sharpener consists of a flat wooden handle glued to a rectangular pad of sandpaper. The end of the handle has a hole for hanging. The back of the handle has a yellow label marked in black: POST'S (/) CHICAGO (/) No. 3000 (/) PENCIL POINTERS. The Frederick W. Post Co.
Description
This pencil sharpener consists of a flat wooden handle glued to a rectangular pad of sandpaper. The end of the handle has a hole for hanging. The back of the handle has a yellow label marked in black: POST'S (/) CHICAGO (/) No. 3000 (/) PENCIL POINTERS. The Frederick W. Post Co. sold this model of pencil pointer with 12 sheets of flint paper for 9¢ in the 1930s. By 1949, the flint paper was replaced with sandpaper.
William J. Ellenberger (1908–2008), who owned this object, 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: Posts Catalog of Dependable Drawing Materials, 18th ed. (Chicago, 1936), 295; Frederick W. Post Co., Drafting Materials for Engineering, Architecture, and Art, 19th ed. (Chicago, 1949–1950), 96; "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
date made
ca 1940
maker
Frederick Post Co.
ID Number
1981.0933.16
accession number
1981.0933
catalog number
1981.0933.16

Conversion Factors, Reference Table for Engineers and Other Executives

This battered table, printed on heavy green paper, gives an alphabetical list of units of measure, conversion factors, and new units of measure. For example, for the unit of measure centimeters, the conversion factor is 0.3937.
Description
This battered table, printed on heavy green paper, gives an alphabetical list of units of measure, conversion factors, and new units of measure. For example, for the unit of measure centimeters, the conversion factor is 0.3937. Multiplying a measurement in centimeters by the conversion factor gives a result in inches.
The table was distributed by Precision Equipment Company of Chicago, Illinois. The back of the table advertises the company’s shelving and safety steps. A sentence at the bottom of the chart reads: Reproduced with the Permission of Foxboro Co. and Exporters’ Digest.
The owner of the table inserted a row with the conversion factor of 1.151 for converting from nautical miles to statute miles.
Exporters’ Digest was published from 1927 through 1958. Foxboro Company was in business from 1912 through 1990. A surviving piece of trade literature suggests that the Precision Equipment Company was in business in the 1950s. Hence the rough date of 1950 assigned to the object.
Location
Currently not on view
date made
ca 1950
ID Number
1981.0922.16
accession number
1981.0922
catalog number
1981.0922.16

Pamphlet, The Comptometer Line

This illustrated pamphlet descriptes the adding machine of Felt and Tarrant Manufacturing Company., including the model K, model J, fractional model J, supertotalizer, and 20-column Comptometers.
Description
This illustrated pamphlet descriptes the adding machine of Felt and Tarrant Manufacturing Company., including the model K, model J, fractional model J, supertotalizer, and 20-column Comptometers. Also described are a Comptometer peg-board for use with formsand a special desk for the Comptometer.
Location
Currently not on view
ID Number
1979.3074.12
nonaccession number
1979.3074
catalog number
1979.3074.12

Arm Protractor and Goniometer Invented by Samuel L. Penfield

It may seem obvious that surveyors, navigators, and mathematics students would need to measure angles. These practitioners are not the only audiences for protractors, however, since angle measurement is necessary in a variety of other fields.
Description
It may seem obvious that surveyors, navigators, and mathematics students would need to measure angles. These practitioners are not the only audiences for protractors, however, since angle measurement is necessary in a variety of other fields. Geologists examine the faces and edges of crystals and recreate the crystals' structures by drawing stereographic projections. In 1900, Samuel Lewis Penfield (1856–1906), a geology professor at Yale University who earned his Ph.B. from Yale in 1877, patented two forms of "contact-goniometer." (A goniometer measures plane angles.) These instruments, along with a stereographic protractor and beam compasses that Penfield patented in 1901, helped establish the technique of stereographic projections in crystallography. Penfield aimed to simplify the work involved in the technique and to produce an inexpensive instrument.
This semicircular paper protractor appears to be an example of the contact-goniometer awarded patent number 655,004 on July 31, 1900. It is printed on a white rectangular card. It is divided by half-angles and marked by tens in both directions (counterclockwise and clockwise) from 0° to 180°. A ruler, divided to millimeters and marked by ones from 0 cm to 14 cm, is printed along the top edge of the card. A diagonal scale and scales for dividing the inch into 10, 12, and 16 parts appear in the interior of the protractor. A celluloid arm is attached at the vertex of the protractor. Users were to set angles according to a horizontal line on the arm but then draw angles along the edge of the arm.
The lower left corner of the card reads: ARM PROTRACTOR AND GONIOMETER (/) Designed by S. L. Penfield. A mark at the lower right corner of the scales of equal parts affirms that the protractor is: ENGINE DIVIDED. The protractor is contained in a paper envelope, which also holds a sheet of instructions written by Penfield. The envelope is imprinted: ARM PROTRACTOR AND GONIOMETER. It is also stamped: Cenco 88210.
The Mineralogical Laboratory of Yale's Sheffield Scientific School offered early versions of this instrument. Central Scientific Company of Chicago (abbreviated Cenco) sold the Penfield arm protractor and goniometer in this form from as early as 1909 (as item 427) to as late as 1950 (as item 88210). In 1914, the instrument cost 67 cents. William C. Marshall (of Bridgeport Works and formerly at the Sheffield Scientific School at Yale) listed it as a required tool in Elementary Machine Drawing and Design (New York: McGraw-Hill, 1912), 8. Edward Salisbury Dana discussed Penfield's instrument in more detail in A Textbook of Mineralogy, With an Extended Treatise on Crystallography and Physical Mineralogy, 3rd ed. rev. William E. Ford (New York: John Wiley & Sons, 1922), 33–40.
References: Samuel Lewis Penfield, "Contact-Goniometer" (U.S. Patent 655,004 filed April 2, 1900), "Contact-Goniometer" (U.S. Patent 655,005 filed April 2, 1900), "Stereographic Protractor" (U.S. Patent 667,570 filed October 25, 1900), and "Beam-Compass" (U.S. Patent 673,687 filed December 31, 1900); S. L. Penfield, "The Stereographical Projection and its Possibilities, from a Graphical Standpoint," American Journal of Science 4th ser. 11 (1901): 1–24, 115–144; Central Scientific Company, Physical and Chemical Apparatus Catalogue M (May, 1914), 42; L. V. Pirsson, "Samuel Lewis Penfield," American Journal of Science, 4th ser. 22 (1906): 353–367; Horace L. Wells, "Samuel Lewis Penfield, 1856–1906," in Biographical Memoirs (Washington, D.C.: National Academy of Sciences, 1909), vi:119–146; Shellie Snell, "Central Scientific Company: A Brief History," Robert A. Paselk Scientific Instrument Museum, Humboldt State University, http://www.humboldt.edu/scimus/Manufac/Cenco/Cenco.htm.
Location
Currently not on view
date made
1909-1950
patent date
1900
maker
Central Scientific Company
inventor
Penfield, Samuel Lewis
ID Number
1982.0147.02
accession number
1982.0147
catalog number
1982.0147.02

Instruction Manual for Pickett Slide Rules with Ln-L Scales

Maurice Hartung of the University of Chicago wrote this sixteen-page booklet to explain the use of natural log and logarithmic scales placed on Pickett's line of "dual-base" slide rules. Its citation information is: Maurice L.
Description
Maurice Hartung of the University of Chicago wrote this sixteen-page booklet to explain the use of natural log and logarithmic scales placed on Pickett's line of "dual-base" slide rules. Its citation information is: Maurice L. Hartung, How to Use Ln-L Scale Slide Rules (Santa Barbara, Calif.: Pickett, Inc., n.d.). The logo and address on the cover were in use from 1964.
Pickett used these scales on several models represented in the Smithsonian collections, including 3, 4, 515, 600, and 1010. The rules depicted in the booklet are models 1011 and 4, similar to 2000.0203.01. Hartung explains how to find logarithms and natural logs (by reading the mantissa), powers of e and 10, logarithms of proper fractions, powers for negative exponents, and the characteristic. He explains how to place the decimal point and how to correct for the error introduced when the number 2.3 is used to estimate e. He then covers multiplication, division, logarithms of combined operations, powers of other bases, hyperbolic functions, and applied problems.
Location
Currently not on view
date made
after 1964
maker
Hartung, Maurice L.
ID Number
1980.0097.04
accession number
1980.0097
catalog number
1980.0097.04

Pickett Manual for Model 3 Duplex Slide Rule

This eight-page pamphlet, titled How to Use Model 3 Powerlog Slide Rules, is a supplement to Maurice L. Hartung, How to Use Dual Base Log Log Slide Rules (Santa Barbara, Calif.: Pickett, Inc., 1947). Hartung also wrote this pamphlet, probably around 1947.
Description
This eight-page pamphlet, titled How to Use Model 3 Powerlog Slide Rules, is a supplement to Maurice L. Hartung, How to Use Dual Base Log Log Slide Rules (Santa Barbara, Calif.: Pickett, Inc., 1947). Hartung also wrote this pamphlet, probably around 1947. He explains scales not found on other Pickett models, namely, the extended square root, cube root, and tangent scales. Model 3 also had an extra log log scale (LL0).
This printing was made after the company moved to Santa Barbara in 1964. See the associated items, 1980.0097.01 and 1980.0097.05.
Location
Currently not on view
date written
1947
date printed
ca 1965
maker
Hartung, Maurice L.
printer
Pickett Industries
ID Number
1980.0097.06
accession number
1980.0097
catalog number
1980.0097.06

Pickett Manual for Dual Base Log Log Slide Rules

Pickett, Inc., was a slide rule manufacturer that started in Chicago in 1943, shifted most of its operations to Alhambra, Calif., in 1946, and moved to Santa Barbara, Calif., in 1964. Maurice L.
Description
Pickett, Inc., was a slide rule manufacturer that started in Chicago in 1943, shifted most of its operations to Alhambra, Calif., in 1946, and moved to Santa Barbara, Calif., in 1964. Maurice L. Hartung, a mathematics professor at the University of Chicago, wrote several instruction manuals for the company, including How to Use Dual Base Log Log Slide Rules. This 93-page booklet was intended for use with Pickett models 2, 3, and 4. It contains sections on the general operation of a slide rule, the use of scales for trigonometry and roots, elementary vector methods, the use of logarithmic scales, practice problems, hyperbolic functions, and circular functions. Hartung also showed how the double T scales could solve side-angle-side triangle problems in one step. Model 600 was advertised at the back of the manual, and instructions for caring for Pickett slide rules were provided inside the back cover.
Although Hartung wrote the manual in 1947, this printing was made after the company moved to Santa Barbara in 1964. See the associated items, 1980.0097.01 and 1980.0097.06.
Location
Currently not on view
date copyrighted
1947
date printed
ca 1965
author
Hartung, Maurice L.
printer
Pickett Industries
ID Number
1980.0097.05
accession number
1980.0097
catalog number
1980.0097.05

Dietzgen Gem Union Drawing Pen

This 5-3/8" steel, German silver, and ebony drawing pen is marked on the blade: E. D.–Co. UNION. A piece missing from the top of the handle may have been intentionally shaved away instead of accidentally broken.As part of its Gem Union product line, the Eugene Dietzgen Co.
Description
This 5-3/8" steel, German silver, and ebony drawing pen is marked on the blade: E. D.–Co. UNION. A piece missing from the top of the handle may have been intentionally shaved away instead of accidentally broken.
As part of its Gem Union product line, the Eugene Dietzgen Co. of Chicago sold similar drawing pens, described as 5-1/2" long, in 1904 as model 502 for $1.20 and in 1926 as model 623 for $4.00. Engineer William J. Ellenberger (1908–2008) owned this pen. For his biography, see 1981.0933.25.
References: Catalog of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 54; Catalog of Eugene Dietzgen Co., 12th ed. (Chicago, 1926), 61.
Location
Currently not on view
date made
early 20th century
maker
Eugene Dietzgen Company
ID Number
1981.0933.23
accession number
1981.0933
catalog number
1981.0933.23

Dietzgen 736B Bow Compass with Pencil Point

This steel and German silver instrument has a needle point on one leg and a holder for a pencil lead on the other. The handle has vertical ridges above a single line of raised metal dots.
Description
This steel and German silver instrument has a needle point on one leg and a holder for a pencil lead on the other. The handle has vertical ridges above a single line of raised metal dots. The width of the compass is adjusted with a pin through the legs and a wheel around the pin between the legs. Additional thumbscrews allow adjusting of the needle and pencil points. The instrument appears to be a Federal Bow Pencil, model number 736B, advertised in 1926 by the Eugene Dietzgen Company of Chicago.
Reference: Catalog of Eugene Dietzgen Co., 12th ed. (Chicago, 1926), 60, 74.
Location
Currently not on view
date made
ca 1926
maker
Eugene Dietzgen Company
ID Number
1981.0933.21
accession number
1981.0933
catalog number
1981.0933.21

How to Use a Slide Rule

The citation information for this eighteen-page booklet is: How to Use a Slide Rule (Chicago: Eugene Dietzgen Co., 1942). After a description of the features of the slide rules sold by Dietzgen, the booklet gives a tour of the slide rule for beginners.
Description
The citation information for this eighteen-page booklet is: How to Use a Slide Rule (Chicago: Eugene Dietzgen Co., 1942). After a description of the features of the slide rules sold by Dietzgen, the booklet gives a tour of the slide rule for beginners. Instructions are provided for reading a basic set of Mannheim scales, such as those on MA.335270. Sample problems in multiplication, division, square roots, proportion, and trigonometry are solved. Additional scales, such as K and CI, are briefly described.
Location
Currently not on view
date made
1942
maker
Eugene Dietzgen Company
ID Number
1981.0933.07
accession number
1981.0933
catalog number
1981.0933.07

Instruction Manual for Pickett 101-C Circular Slide Rule

This 24-page booklet was received with 1981.0922.12. Its citation information is: Maurice L. Hartung, Dial Rule Circular Slide Rule: Your Model No. 101-C Instruction Manual (Chicago & Alhambra, Calif.: Pickett & Eckel, Inc., 1957).
Description
This 24-page booklet was received with 1981.0922.12. Its citation information is: Maurice L. Hartung, Dial Rule Circular Slide Rule: Your Model No. 101-C Instruction Manual (Chicago & Alhambra, Calif.: Pickett & Eckel, Inc., 1957). The back is marked: PRINTED IN U.S.A.; FORM M-18. The Pickett logo on the front cover was used between 1958 and 1962.
The manual provides instructions and processes for the C and CI scales, multiplication, division, combined operations, the A and Af scales (for square roots), logarithms and adding fractions, the LL scale, the DS and DT scales (for drill sizes and double depth of threads), the M scale (for metric conversions), and the S, ST, and T scales (for trigonometry). There are 24 problems and answers on the back page.
Location
Currently not on view
date made
ca 1958
publisher
Pickett Industries
author
Hartung, Maurice L.
ID Number
1981.0922.13
accession number
1981.0922
catalog number
1981.0922.13

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