Protractors - School

Although protractors began to appear in practical geometry textbooks in the 18th century, it was not until the turn of the 20th century that they were used systematically in mathematics teaching in American schools. Some protractors were small and inexpensive, intended for purchase and use by individual students. These might be made from new materials, such as plastic. Other protractors for educational use were oversized, designed for teachers to provide demonstrations of concepts at the blackboard. Two protractors in the collection were manufactured in Japan and displayed at the 1876 World's Fair to help demonstrate the modernization of education in that nation.
"Protractors - School " showing 5 items.
Hart Combination Protractor, Rule, and Square
- Description
- This paper semicircular protractor is divided by degrees and marked by tens from 10 to 170 degrees in both directions. The letter A is printed in the bottom left corner of the protractor, and B is printed in the bottom right corner of the protractor. Centered under the origin point of the protractor is printed the inventor's mark: Combination Protractor, Rule, and Square (/) W. W. Hart, University of Wisconsin.
- A ruler along the top edge is divided to 1/8-inch and marked by ones from 0 to 5. A ruler along the bottom edge is divided to millimeter and marked by ones from 0 to 12. The typeface of the inventor's mark is similar to that shown in Hart's textbooks published in the 1920s, such as Walter Wilson Hart, Junior High School Mathematics, vol. 1 (Boston: D. C. Heath & Co., 1921), vii, 131. See also MA*304722.06.
- Location
- Currently not on view
- date made
- ca 1925
- designer
- Hart, Walter Wilson
- ID Number
- MA*304722.07
- accession number
- 1973.304722
- catalog number
- 304722.07
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Hart Combination Protractor, Rule, and Square
- Description
- In the early 20th century, some authors of mathematics textbooks and their publishers began to include protractors in the endpapers of the books. They wanted middle and high school students to informally experience geometry through drawing and experiment before moving on to constructing formal geometrical proofs. Walter W. Hart, a professor of mathematics at the University of Wisconsin, went so far as to design a combination protractor and ruler for insertion in the textbooks he authored with professional mathematics textbook author Webster Wells.
- By 1921, Hart's protractor was described and illustrated in the text with a cardboard version included for student use. If students lost their protractors, teachers could order replacements from D. C. Heath & Co. for four to five cents each, depending on the quantity ordered. By 1926, Hart was boasting that his invention had anticipated the standards recommended in 1923 by the Mathematical Association of America's National Committee on Mathematical Requirements. This example probably dates from one of Hart's later textbooks.
- This paper semicircular protractor is divided by degrees and marked by tens from 10 to 170 degrees in both directions. The letter A is printed in the bottom left corner of the protractor, and B is printed in the bottom right corner of the protractor. Centered under the origin point of the protractor is printed the inventor's mark: COMBINATION PROTRACTOR, RULE, AND SQUARE (/) W. W. HART, UNIVERSITY OF WISCONSIN. A ruler along the top edge is divided to 1/8-inch, and marked by ones from 0 to 5. A ruler along the bottom edge is divided to millimeters and marked by ones from 0 to 12. This protractor was donated by the Brown University mathematics department in 1973. It is notably discolored and stained. See also MA*304722.07.
- References: Peggy Aldrich Kidwell, Amy Ackerberg-Hastings, and David Lindsay Roberts, Tools of American Mathematics Teaching, 1800–2000 (Baltimore: Johns Hopkins University Press, 2008), 176–179, 364–365; Walter Wilson Hart, Junior High School Mathematics, vol. 1 (Boston: D. C. Heath & Co., 1921), vii, 131; Webster Wells and Walter W. Hart, Modern Plane Geometry (Boston: D. C. Heath & Co., 1926), 3, 16; National Committee on Mathematical Requirements, The Reorganization of Mathematics in Secondary Education ([Oberlin, OH]: Mathematical Association of America, 1923), 22. See also Walter Wilson Hart, Progressive Plane and Solid Geometry (Boston: D. C. Heath & Co., 1936), iii–vii, 16–17; Claude H. Ewing and Walter W. Hart, Essential Vocational Mathematics (Boston: D. C. Heath & Co., 1945), 99; and Walter Wilson Hart, Veryl Schult, and Henry Swain, Plane Geometry and Supplements (Boston: D. C. Heath & Co., 1959), 24.
- Location
- Currently not on view
- date made
- after 1930
- Date made
- post 1930
- designer
- Hart, Walter Wilson
- ID Number
- MA*304722.06
- accession number
- 1973304722
- catalog number
- 304722.06
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Dietzgen 1298-D Blackboard Protractor
- Description
- In the 16th and 17th centuries, surveyors and navigators began to use instruments made especially for measuring off angles. These were generally small instruments made of metal and finely divided. In the years following the Civil War, as the number of American high schools grew, so did the number of students studying practical geometry and trigonometry. To teach them, teachers used inexpensive protractors made for use at the blackboard.
- This example is made of fiberboard, painted white on the front, and has a wooden handle so that it can be held upright. It is divided along the edge to intervals of 5 degrees. By comparison, most protractors are divided much more finely. The Eugene Dietzgen Co. of Chicago sold blackboard protractors like this one from about 1925. This example dates from around 1950 and was used at Montgomery College in Takoma Park, Maryland.
- Location
- Currently not on view
- date made
- ca 1950
- maker
- Eugene Dietzgen Company
- ID Number
- 1999.0117.02
- catalog number
- 1999.0117.02
- accession number
- 1999.0117
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Safe-T Semicircular School Protractor
- Description
- This clear plastic semicircular protractor arrived at the Smithsonian in a clear plastic wrapper, which is stored with it. Designed for use by schoolchildren, it contains four sets of divisions, three to single degrees and the innermost one to ten degrees.
- The outer two divisions are marked by tens for reading left-opening angles, from 0° to 180°. The inner two divisions are marked by tens for reading right-opening angles, from 170° to 0°. A semicircular slot separates the two scales.
- The interior of the protractor is open. A scale along the bottom edge of the opening is divided to millimeters and marked by centimeter from 0 to 10. The outer bottom edge of the protractor is divided to sixteenths of an inch and is marked by inches from 1 to 6. The corners are slightly rounded.
- The object bears several marks along its diameter edge: PAT. [/] PENDING; SAFE-T TM [/] PRORUCTS [sic] Inc.; Angles Opening Left (>) [/] Use Upper Scale; VIEW-THRU TM [/] SAFE-T PLASTIC TM [/] #45780; Angles Opening Right (<) [/] Use Lower Scale; La Grange, IL [/] 60525-0692.
- Reference: SAFE-T Products, Inc., Innovative Safe Drawing and Measuring Instruments, about 1998. According to this catalog, these protractors sold individually for 75 cents. In 2006, the company became a subsidiary of A. Daigger & Company and its name changed to Classroom Products Warehouse.
- Location
- Currently not on view
- date made
- 1998
- maker
- Safe-T Products, Inc.
- ID Number
- 1998.0033.02
- catalog number
- 1998.0033.02
- accession number
- 1998.0033
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Safe-T 45779 Blackboard Protractor
- Description
- This oversized white plastic semicircular protractor may be used at a chalkboard or whiteboard. A smaller semicircle is cut out of the protractor's interior. Three curved grooves form a third semicircle between these two semicircles. The protractor is divided by single degrees and in three rows of divisions. It is marked by tens from 0° to 180° (left to right) and from 180° to 0° (right to left).
- An oversized ruler, or scale of equal parts, divided to mm and marked by single cm from 1 to 10, is on the diameter of the innermost semicircle. A notch for the origin point of the protractor is at the center of this edge. Another scale of equal parts, divided by 16ths of an inch and marked by ones from 1 to 6, is along the outer lower edge.
- The protractor is marked: Angles Opening Left (>) Use Upper Scale; Angles Opening Right (<) Use Lower Scale (/) SAFE-T PROTRACTOR® #45779. A recycling logo for plastic type 6 appears in the lower right corner. The protractor retailed for approximately $13 in 2011.
- See also ID numbers 1998.0033.02 and 1999.0117.02.
- Location
- Currently not on view
- date made
- ca 2000
- Associated Date
- 2000
- maker
- Safe-T Products, Inc.
- ID Number
- 2000.0160.03
- accession number
- 2000.0160
- catalog number
- 2000.0160.03
- Data Source
- National Museum of American History, Kenneth E. Behring Center

