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 1 items.
- This clear plastic semicircular protractor is contained within an irregularly shaped piece of plastic that features a French curve at the top, two triangles (of 60° and 45°) on the sides, and a 5-1/2" scale along the bottom.
- The scale is divided to 16ths of an inch and is marked by single inches from 1" to 5". The protractor is divided to single degrees and marked by tens from 10° to 90° to 170° and from 170° to 90° to 10°. A semicircular slot separates the protractor from the French curve. Cut-out stencils for six circles range in diameter from 1/8" to 7/16". Also included are two slots for drawing angles of 30° and 45° and templates for an equilateral hexagon and two closed curves. On the curve the object is marked: SP [/] PROTRACTOR – FRENCH CURVE – TRIANGLES – RULER – CIRCLE GAUGES. Between the protractor and scale, the object is marked: MADE IN U.S.A.; 2; STERLING 544. The markings were stamped in black but are wearing off.
- Sterling Plastics was operated by George and Mary Staab in Mountainside, N. J., through the late 1960s. It was a division of Borden Chemical Company in the 1970s and 1980s, during which time this object was called the 7-IN-1 Protractor. For other products of Sterling Plastics, see slide rule 1988.0807.01 and adding machine MA*335327. James J. Williams gave this protractor to the Smithsonian.
- Reference: Toxic Substances Control Act: Trademarks and Product Names Reported in Conjunction with the Chemical Substance Initial Inventory (Washington, D.C.: United States Environmental Protection Agency, 1979), 90.
- Currently not on view
- date made
- ca 1975
- Sterling Plastics
- ID Number
- nonaccession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center