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
- Object Name
- protractor
- date made
- ca 1950
- maker
- Eugene Dietzgen Company
- Physical Description
- wood (overall material)
- Measurements
- overall: 2.5 cm x 39.5 cm x 20 cm; in x 15 9/16 in x 7 7/8 in
- place made
- United States: Illinois, Chicago
- ID Number
- 1999.0117.02
- catalog number
- 1999.0117.02
- accession number
- 1999.0117
- subject
- Protractors
- Education
- Mathematics
- Science & Mathematics
- See more items in
- Medicine and Science: Mathematics
- Protractors
- Data Source
- National Museum of American History, Kenneth E. Behring Center
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