Dietzgen 1298-B Blackboard Ruler

This three-foot wooden rule was sold as part of a set of instruments for blackboard use. It is divided to 1/8" along one edge and numbered in red for feet and in black for inches. A horizontal handle in the center of the rule assists with positioning it against the blackboard, and a round hole at the right end is for hanging the instrument. The lower right corner is marked: DIETZGEN (/) MADE IN U.S.A. (/) 1298-B.
The Eugene Dietzgen Company of Chicago began numbering its blackboard drawing instruments individually by 1910, when it priced the four pieces at $1.25 each or $5.00 for the set. However, through at least 1938, the handle on the ruler was shaped like a knob, not as a horizontal bar. For related object, see 1999.0117.02.
References: Catalogue & Price List of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 151; Catalogue & Price List of Eugene Dietzgen Co., 9th ed. (Chicago, 1910–1911), 194; Catalogue & Price List of Eugene Dietzgen Co., 15th ed. (Chicago, 1938), 210.
Currently not on view
Object Name
scale rule
date made
ca 1950
Eugene Dietzgen Company
Physical Description
wood (overall material)
overall: 2 cm x 92.6 cm x 5.3 cm; 25/32 in x 36 15/32 in x 2 3/32 in
place made
United States: Illinois, Chicago
ID Number
catalog number
accession number
Rule, Measuring
Education, College
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Scale Rules
Data Source
National Museum of American History, Kenneth E. Behring Center


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