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Darling & Bailey Drafting Rule

Darling & Bailey Drafting Rule

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Four scales of inches are on this two-sided, 12-inch steel rule used for engineering drawing. On one side, nine inches of one scale are divided to 1/10", one inch is divided to 1/20", one inch is divided to 1/50", and one inch is divided to 1/100". Ten inches of the other scale are divided to 1/16", one inch is divided to 1/32", and one inch is divided to 1/64". The ruler is marked: D. & B. (/) BANGOR Me. (/) U.S. Stnd. It is also engraved: W.A.L.
On the other side, ten inches of one scale are divided to 1/12", one inch is divided to 1/24", and one inch is divided to 1/48". Eleven inches of the other scale are divided to 1/14", and one inch is divided to 1/28". The ruler is engraved: W.A.L.
A farmer and sawmill owner turned toolmaker, Samuel Darling (1815–1896) apparently first made machine tools in 1846. He built a dividing engine and partnered with Edward H. Bailey in Bangor, Me., in 1852. The next year, Darling received his first patent and bought out Bailey, and by 1854 he was in partnership with Michael Schwartz of Bangor. That business lasted until Darling moved his craftsmen and equipment to Brown & Sharpe's Providence, R.I., workshop in 1866. Thus, this object was made between 1852 and 1853. For a drafting tool invented by Darling, see 1977.0460.01 and 1990.0317.02.
An unidentified relative of Erasmus Darwin Leavitt Jr. (1836–1916), the renowned American mechanical engineer and designer of steam engines, owned this rule. (None of Leavitt's children had names that began with "W," and his father's name was also Erasmus.)
References: Samuel Darling, "Apparatus for Grinding and Shaping Metals" (U.S. Patent 9,976 issued August 30, 1853); Davistown Museum, "Registry of Maine Toolmaker Listings," http://www.davistownmuseum.org/TDMtoolMakers.html; Henry Dexter Sharpe, A Measure of Perfection: The History of Brown & Sharpe (North Kingston, R.I.: Brown & Sharpe, 1949), http://www.roseantiquetools.com/id44.html.
Currently not on view
Object Name
scale rule
date made
Darling, Samuel
place made
United States: Maine, Bangor
Physical Description
steel (overall material)
overall:.2 cm x 30.5 cm x 3.2 cm; 3/32 in x 12 in x 1 1/4 in
ID Number
accession number
catalog number
Credit Line
Gift of Margaret van D. Rice
Drafting, Engineering
Rule, Measuring
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Scale Rules
Data Source
National Museum of American History
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