Our museum is temporarily closed to support the effort to contain the spread of COVID-19. Read a message from our director, and check our website and social media for updates.

Plotting Scale

Plotting Scale

<< >>
Usage conditions apply
This two-sided boxwood rule has a scale of chords and architect's scales dividing the inch into 40, 35, 30, 25, 20, and 15 parts on one side. A white sticker on that side is marked: 783. The other side has an inch scale divided to 1/10" and numbered by ones from 1 to 6; a scale divided to ones and numbered by tens from 10 to 50 (10 units is approximately 3 cm); and 5" plotting scales with diagonal scales at each end. One plotting scale is divided to 1/2" and numbered by ones from 10 to 1, and the other is divided to 1/4" and numbered by ones from 1 to 18. One edge of the rule is scalloped.
The previous owner collected more than 1,200 hand tools and machine tools and displayed them at his family's building company in Baltimore, Md. This object was item number 783 in his collection. It probably dates to the turn of the 20th century. Similar scales were sold for 10¢ to 15¢ by Dietzgen (model number 1690) from at least 1902 to 1912 and by Keuffel & Esser (model number 1616) from at least 1892 to 1913. Both companies stopped advertising the object before 1921.
References: Catalog of Eugene Dietzgen Co., 6th ed. (Chicago, 1902), 135; Catalog of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 162; Catalog of Eugene Dietzgen Co., 9th ed. (Chicago, 1910–1912), 207; Catalogue of Keuffel & Esser Co., 23rd ed. (New York, 1892), 126; Catalogue of Keuffel & Esser Co., 33rd ed. (New York, 1909), 189; Catalogue of Keuffel & Esser Co., 34th ed. (New York, 1913), 184.
Currently not on view
Object Name
scale rule
date made
ca 1900
Physical Description
wood (overall material)
overall:.1 cm x 15.4 cm x 3.4 cm; 1/32 in x 6 1/16 in x 1 11/32 in
ID Number
accession number
catalog number
Credit Line
The John R. Gerwig, Jr., Collection
Drawing Instruments
Drafting, Engineering
Rule, Measuring
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Scale Rules
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object