Beam Compass

This instrument consists of a wooden beam and a single German silver trammel with a micrometer and needle point. A large round hole in one end of the beam allows the instrument to be hung. The other end of the beam is marked in pencil at each of the first six inch points. The trammel is similar but not fully identical to Dietzgen's model number 646, which sold with a pair of trammels, two needle/pencil points, and a pen point for $9.20 in 1904–1905. This instrument was owned by the renowned American designer of steam engines, Erasmus Darwin Leavitt Jr. (1836–1916), and donated by his granddaughter, Margaret van D. Rice.
Reference: Catalogue & Price List of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 71.
Currently not on view
Object Name
beam compass
date made
ca 1900
Physical Description
metal (overall material)
wood (overall material)
overall: 34.5 cm x 6.4 cm x 1.4 cm; 13 19/32 in x 2 17/32 in x 9/16 in
ID Number
accession number
catalog number
Drawing Instruments
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Dividers and Compasses
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Margaret van D. Rice

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.