Triangular Scale Signed W. Metcalf

On one face this 12" steel triangular rule has scales for 3/16" and 3/8" to the foot. Between these scales is a scale divided to 3/32", numbered from left to right by twos from 0 to 62, and numbered from right to left by fours from 4 to [1]24. The second face has a scale of inches numbered by ones from 1 to 12. The first two inches are divided to 1/128"; the next two inches are divided to 1/64"; inches 4–6 are divided to 1/32"; inches 6–8 are divided to 1/16"; and inches 8–12 are divided to 1/8".
The third face also has a scale of inches numbered by ones from 1 to 12. The first two inches are divided to 1/100"; the next two inches are divided to 1/50"; inches 4–6 are divided to 1/20"; inches 6–8 are divided to 1/96"; inches 8–10 are divided to 1/48"; and inches 10–12 are divided to 1/24". This side is marked: W. Metcalf 1882.
Sisters Elizabeth Henshaw Metcalf (1852–1925) and Sarah Spathding Metcalf (1858–1939) donated this rule to the Smithsonian in 1931, within several containers of materials sent from the family home in Worcester, Mass. The bulk of the materials were ethnographic specimens collected by the women as they visited and lived in the Philippines at various times between 1905 and their deaths. The name on the rule probably refers to their brother, Wallace Metcalf (1854–1904). He graduated from Worcester Polytechnic Institute with a degree in mechanical engineering in 1873, lived with his sisters for many years, and worked in Worcester as a civil engineer.
References: Cherubim A. Quizon, "Two Yankee Women at the St. Louis Fair: The Metcalf Sisters and their Bagobo Sojourn in Mindanao," Philippine Studies 52, no. 4 (2004): 527–555; "Alumni Notes," The Journal of the Worcester Polytechnic Institute 7, no. 4 (May 1904): 355; accession file.
Currently not on view
Object Name
scale rule, triangular
rule, triangular
date made
Metcalf, W.
Physical Description
steel (overall material)
overall: 1 cm x 30.1 cm x 1.2 cm; 13/32 in x 11 27/32 in x 15/32 in
ID Number
accession number
catalog number
Scale Rules
Science & Mathematics
Rule, Measuring
Drafting, Engineering
See more items in
Medicine and Science: Mathematics
Scale Rules
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Elizabeth H. and Sarah S. Metcalf
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