Japanese Scale Rule with Chain

This brass rule with chain was displayed by the Japanese Empire Department of Education at the 1876 Centennial Exhibition in Philadelphia and then was held by the Museum of the U.S. Bureau of Education before transfer to the Smithsonian in 1910. The scale on the rule has six units of 19/32" (1.5 cm). Two of the units are subdivided into 25 parts; the other two are subdivided into ten parts. The chain is approximately 29-1/2" (75 cm) long and is attached to an eye at one end of the rule. Larger links are inserted in the chain at 12" and 24" from the rule. A small octagonal weight (about 1/2" or 1.5 cm long) is attached to the end of the chain.
The accession record identifies this instrument as a ryosan shaku (depth gauge for cannon barrels). For more information on the exhibition, see MA*261298 and MA*261313.
Currently not on view
Object Name
scale rule
date made
before 1876
Physical Description
brass (overall material)
overall: 1.1 cm x 88.2 cm x 1.1 cm; 7/16 in x 34 23/32 in x 7/16 in
place made
ID Number
accession number
catalog number
Scale Rules
Science & Mathematics
Expositions and Fairs
See more items in
Medicine and Science: Mathematics
Scale Rules
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Transfer from Bureau of Education, Department of the Interior
Additional Media

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.