Protractors - Engineering & Drafting
By the end of the 18th century, protractors were routinely manufactured by machinery, with the invention of dividing engines, such as Jesse Ramsden's, particularly important for enabling the precise division of a circle into fractions of angles. Makers produced protractors that read minute fractions of angles, particularly when a vernier was added to the instrument.
Mechanics or machinists also used protractors to draw designs for new types of machinery. For instance, there were several forms of limb protractors for draftsmen that both functioned as T-squares and provided angle measurement. Similarly, protractors assisted with the preparation of architectural drawings. The instruments were only displaced by the advent of computer-aided drafting in the late 20th century.
"Protractors - Engineering & Drafting" showing 6 items.
Lyman Protracting Trigonometer Signed Heller & Brightly
- Description
- This metal drawing instrument allows civil engineers to translate their measurements into drawings with a minimum of calculation. It consists of a flat steel base bar 81.5 cm (about 32 inches) long, a semicircular protractor with a flat plate along the diameter that slides along the base bar, a long steel arm clamped to the protractor at its center, a brass set square or sliding square that moves along the arm, and a tri-leaved scale (like an architect’s scale) that moves along the arm or along the set square. There are four metal springs, each with its own screw. The two smaller springs hold the protractor plate to the base bar and the two larger ones hold the tri-leaved scale or the set square to the arm. The entire instrument fits in a wooden case. A sheet of instructions is pasted inside the case.
- The protractor is divided by half-degrees and marked by tens from 0° to 90° to 0° and from 90° to 0° to 90°. An attached vernier permits angle readings to one minute of arc. The ratios on the architect's scales range from 1:10 to 1:60. Each scale is divided into tenths of a unit.
- This is a modified form of the protracting trigonometer patented by Josiah Lyman of Lenox, Mass., in 1858, with reissue of the patent in 1860, and extension in 1872 (for an example of the protracting trigonometer, see MA*328738; for an architect’s rule patented by Lyman, see MA*308914). The instrument was made by Heller & Brightly of Philadelphia. According to a Heller & Brightly circular, the instrument sold with either a tri-leaved scale that was 6 inches long or one that was 12 inches long. This instrument has the 12-inch scale, and would have sold in 1878 for $30.00.
- Hobart Cutler Dickinson (1875–1949), a 1900 graduate of Williams College who obtained a master’s degree there and did further graduate work at Clark University (Ph.D. 1910), owned this object. Dickinson worked at the U.S. National Bureau of Standards from 1903 until his retirement in 1945. Dickinson was the father of Anne D. Ross, one of the donors of the instrument.
- References: "Circular of Lyman’s Trigonometer and Universal Draughting Instrument" (Philadelphia: Heller & Brightly, 1878); P.A. Kidwell, “Josiah Lyman’s Protracting Trigonometer,” Rittenhouse, 3 (November 1988): 11–14; Robert C. Miller, “A Lyman Protracting Trigonometer Made by Heller & Brightly,” Rittenhouse 3 (August 1989): 129–131.
- Location
- Currently not on view
- date made
- ca 1880
- maker
- Heller & Brightly
- ID Number
- 2009.0244.01
- accession number
- 2009.0244
- catalog number
- 2009.0244.01
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Brown & Sharpe Draftsman's Protractor
- Description
- In the late 19th century, American draftsmen experimented with different designs for making protractors more versatile. For instance, the secretive machinist Samuel Darling, who operated a separate partnership with Joseph R. Brown and Lucian Sharpe of Providence, R.I., between 1866 and 1892, patented a "bevel and protractor" on July 19, 1887. This was a nearly circular protractor with an extended arm that slid along and rotated around a ruler.
- Alton J. Shaw, who apprenticed in the main firm of Brown & Sharpe, came up with a design that was less cumbersome than Darling's. Although Shaw filed for a patent one month before Darling did, Shaw's patent was not granted until August 2, 1887. His protractor consisted of a circle with an extending arm, cut from sheet steel, which fit on a groove within a three-sided square, also cut from sheet steel. An advantage of this protractor was its reversibility. Shaw assigned his patent to Darling, Brown, & Sharpe on August 19 in exchange for $75. The firm marketed the protractor for $6.50, or for $7.75 with a case. In its catalogs, Brown & Sharpe adopted the British spelling, "draughtsmen's".
- This instrument is an example of Shaw's design. The protractor is divided by single degrees and marked by fives from 0 to 90 in the clockwise direction. Thirty more unnumbered divisions extend past the 90° mark. A vernier on the frame allows angles to be measured to one minute of arc. The interior of the protractor is marked: Darling, Brown & Sharpe. (/) Providence. R.I. (/) Pat. Aug. 2. 1887. The protractor is in a wood and morocco leather case that is lined with purple velvet. The case has broken apart into at least three pieces. A worn instruction sheet (ID number MA*336072.1.1), dated August 1889, is stored with the object. The instructions indicate that a guiding lever, which was placed in two of the eleven holes at the top of the protracting circle, is missing from the object.
- Shaw later moved to Milwaukee, Wis., and then to Muskegon, Mich., where he established the Shaw Electric Crane Company. The company became Lift-Tech International in 1986. The Brown & Sharpe Mfg. Co. absorbed Darling, Brown & Sharpe in 1892. After over a century as one of the largest American machining firms, Brown & Sharpe ceased manufacturing machine tools and drawing instruments in 1991. The firm now manufactures optical measuring instruments as a subsidiary of Hexagon Metrology.
- This protractor was owned by the renowned American designer of steam engines, Erasmus Darwin Leavitt Jr. (1836–1916), and donated by his granddaughter, Margaret van D. Rice.
- See also ID number 1990.0317.02.
- References: Oscar James Beale, Practical Treatise on Gearing (Providence, R.I.: Brown & Sharpe Mfg. Co., 1886), 73-75; Samuel Darling, "Bevel and Protractor" (U.S. Patent 366,651 issued July 19, 1887); Alton J. Shaw, "Protractor" (U.S. Patent 367,673 issued August 2, 1887); Amy Ackerberg-Hastings, "The Brown & Sharpe Draftsmen's Protractor," Rittenhouse 15, no. 1 (2001): 31–38; Henry Dexter Sharpe, A Measure of Perfection: The History of Brown & Sharpe (North Kingston, R.I.: Brown & Sharpe, 1949), http://www.roseantiquetools.com/id44.html.
- Location
- Currently not on view
- date made
- 1889-1892
- patent date
- 1887
- maker
- Brown and Sharpe Manufacturing Company
- inventor
- Darling, Samuel
- ID Number
- 1977.0460.01
- accession number
- 1977.0460
- catalog number
- 336072
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Brown & Sharpe Bevel Protractor
- Description
- This metal instrument consists of a circular protractor housed within an irregularly shaped blade. An 11-1/2" trapezoidal blade slides into the housing. A screw on the protractor fixes that blade in place. The protractor is divided by single degrees and marked by tens from 0° to 90° to 0° to 90° to 0°. A vernier, attached by another screw, permits angle readings to five minutes of accuracy. The protractor has a hinged case of leather over wood, lined with black satin. The case is gouged in several spots.
- Brown & Sharpe Manufacturing Co. introduced a "universal bevel protractor" in 1899, according to "Trade Notes," Science and Industry 4 (1899–1900): 274–275. Although there is no signature on this instrument, this protractor matches the illustrations in this article and in Brown & Sharpe catalogs at least as early as 1899 and at least as late as 1948.
- References: Kenneth L. Cope, intro., A Brown & Sharpe Catalogue Collection, 1868 to 1899 (Mendham, N.J.: The Astragal Press, 1997); Brown & Sharpe Mfg. Co., Small Tools: Catalog No. 27 (Providence, R.I., 1916), 92–93; The Brown & Sharpe Handbook: A Guide for Young Machinists (Providence, R.I., 1948), 49–54, 110–112.
- Location
- Currently not on view
- date made
- 1899-1949
- maker
- Brown and Sharpe Manufacturing Company
- ID Number
- 1986.0316.03
- accession number
- 1986.0316
- catalog number
- 1986.0316.03
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Dietzgen Limb Protractor
- Description
- This German silver protractor is in the shape of a quarter-circle. It is divided by half-degrees and marked by tens from 0° to 90°. Flat bars extend on both sides of the protractor. A movable arm extends from the vertex of the quadrant. A tab is cut out from this limb to permit reading the angle markings. The arm is secured by a brass thumbscrew that is near the origin point for the angle markings. The protractor is noticeably rusted and tarnished.
- There is a signature on the bottom edge: E. D. – Co. (/) NEW YORK & CHICAGO. Around 1880, Eugene Dietzgen emigrated from Germany and became a sales distributor for Keuffel & Esser in New York. In 1885, he began to sell mathematical instruments on his own in Chicago. In 1893, his firm started manufacturing instruments under the name Eugene Dietzgen Company. However, this protractor was not advertised in Dietzgen catalogs that were published between 1902 and 1947.
- Leslie Leland Locke (1875–1943) originally owned this protractor. A student at Grove City College, he earned a bachelor's degree in 1896 and a master's degree in 1900. He taught mathematics at Michigan State College, Adelphi College, and Brooklyn College and its Technical High School. He was interested in Peruvian quipu, mysterious and ancient systems of knotted strings used to store and communicate information and data. He donated his collection of early calculating machines to the Smithsonian and his early American textbooks to the University of Michigan.
- Reference: Louis C. Karpinski, "Leslie Leland Locke," Science n.s., 98, no. 2543 (24 September 1943): 274–275.
- Location
- Currently not on view
- date made
- ca 1900
- maker
- Eugene Dietzgen Company
- ID Number
- 2011.0129.01
- accession number
- 2011.0129
- catalog number
- 2011.0129.01
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Semicircular Protractor Retailed by Post
- Description
- This semicircular brass protractor is divided by single degrees and marked by tens from 0° to 180° in both the clockwise and counterclockwise directions. The bottom edge is indented so that a pencil or pricker may be placed at the origin point. The protractor bears three marks: POSTS; MADE IN GERMANY; and a fleur-de-lis pointing to the origin. The Frederick W. Post Company, a Chicago mathematical instruments dealer established in 1893, used the type style found on this protractor in the 1920s and 1930s. However, the brass protractor depicted in Post's 1936 catalog is not indented on its lower edge, and it shows an eagle under the maker's mark.
- 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, Ellenburger 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: Frederick W. Post Company, Dependable Drawing Materials, 18th ed. (Chicago, 1936), 195; "The G[eorge] W[ashington] Engineering Hall of Fame 2006 Inductees," http://www.seas.gwu.edu/ifaf/hall_of_fame_inductees_2006.php.
- Location
- Currently not on view
- date made
- 1920-1940
- maker
- Frederick Post Co.
- ID Number
- 1981.0933.18
- accession number
- 1981.0933
- catalog number
- 1981.0933.18
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Brown & Sharpe 510 Draftsman's Protractor
- Description
- See also ID number 1977.0460.01. After the inventor of this draftsman's protractor, Alton J. Shaw, left Darling, Brown & Sharpe of Providence, R.I., Samuel Darling patented a vernier scale that was a fraction of the size of a standard vernier scale. Darling then claimed to apply his vernier to the draftsman's protractor, replacing the original patent date in the maker's mark with the December 2, 1890, date of this patent. See, for example, the illustration in Brown & Sharpe's 1899 Catalogue No. 101 and Price Lists. This vernier read to only five minutes of accuracy, while Shaw's earlier vernier read to one minute of accuracy. Darling argued, however, that the coarser scale was easier to read and sufficed for most situations that arose in engineering drawing.
- In any event, the draftsman's protractor continued to sell steadily into the 20th century. Advertisements extolled the instrument's versatility, including its ability to function as a drawing triangle and as an extension of a T-square. The original patent date reappeared on the instrument in 1902 and 1904 but disappeared again by 1916, by which time Brown & Sharpe also changed the protractor's catalog number from 530 to 510. Other dealers, including Keuffel & Esser, W. & L. E. Gurley, and L. S. Starrett, also sold the draftsmen's protractor.
- The chief difference between this example of the instrument and ID number 1977.0460.01 is the reduced precision of the vernier, which is even marked: FIVE MINUTES. This protractor has 40 unmarked divisions, instead of 30. The signature is: 510; BROWN & SHARPE MFG. CO. (/) PROVIDENCE. R.I. U.S.A. The handle also bears the Brown & Sharpe logo of two rectangles at right angles to one another, with the letters B∙S above the horizontal rectangle and the words TRADE MARK below the horizontal rectangle. Of surviving 20th-century Brown & Sharpe catalogs, this protractor most closely resembles the illustration printed in 1925. The extending arm of the protractor is rusting.
- The protractor is stored in a blue paper box covered with the company logo and the words BROWN & SHARPE. A label on one end of the lid reads: 510; ORDER BY NUMBER 599-510 (/) BROWN & SHARPE DRAFTSMEN'S PROTRACTOR (/) MADE IN U.S.A. A label on the other end of the lid reads: POST (/) 0585 (/) THE FREDERICK POST CO. CHICAGO. Post retailed scientific and drawing instruments in the 20th century. An undated sheet with tables of angles for dividing circles and for tapers per foot is in the box.
- References: Samuel Darling, "Vernier-Scale" (U.S. Patent 442,020 issued December 2, 1890); Kenneth L. Cope, intro., A Brown & Sharpe Catalogue Collection, 1868 to 1899 (Mendham, N.J.: The Astragal Press, 1997); Brown & Sharpe Mfg. Co., Catalogue (Providence, R.I., 1902), 372; Brown & Sharpe Mfg. Co., Catalogue No. 138 (Providence, R.I., 1925), 504–505.
- Location
- Currently not on view
- date made
- ca 1925
- maker
- Brown and Sharpe Manufacturing Company
- ID Number
- 1990.0317.02
- accession number
- 1990.0317
- catalog number
- 1990.0317.02
- Data Source
- National Museum of American History, Kenneth E. Behring Center