Object Details
- Darling, Brown & Sharpe
- Description
- This nickel-plated steel instrument is crimped in the middle so that the scales along both edges are angled, giving the object the appearance of a triangle and bringing the scale closer to the draftsman's work. Both edges have scales dividing three inches into 96 parts and scales divided to 3" and numbered by ones from 0 to 3. One edge is marked: D.B.&S. PROV. R.I. Pt. Aug. 3. 80. The crimp is marked: No. 1.
- Draftsmen and architects could use this rule to make scale drawings in which 3" = 1'. Samuel Darling, a machinist who partnered between 1866 and 1892 with Joseph R. Brown and Lucian Sharpe of Providence, R.I., patented the general design in 1880. He desired a material that was not as susceptible to environmental changes as wood and a design that was not as heavy and expensive as the early forms of tubular triangular rules being manufactured by Darling, Brown & Sharpe and other firms.
- Darling, Brown & Sharpe sold the rule in graduations from 3" = 1' to 1/2" = 1' for $1.00. ID number 1977.0460.07 is the same rule with a 1" = 1' scale. For engineers, the rule was available divided from 20ths to 1,000ths of an inch. A "miscellaneous" version had different scales on each edge, graduated along the entire edge in increments from 1/16" to 1/100". In its advertisements, which used the English spelling for "draughtsmen," the company explained that putting only one scale on each instrument would help prevent draftsmen from becoming confused and making mistakes.
- The Brown & Sharpe Manufacturing Company continued to sell the rule after Darling's interest was bought out in 1892. The company then offered the scale in graduations down to 1/8" = 1' and increased the price to $1.25. By 1929, Brown & Sharpe offered only the miscellaneous version for $2.00. This example 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.
- References: Samuel Darling, "Graduated Measuring Rule" (U.S. Patent 230,619 issued August 3, 1880); Kenneth L. Cope, intro., A Brown & Sharpe Catalogue Collection, 1868 to 1899 (Mendham, N.J.: The Astragal Press, 1997), 119, 160–161; Brown & Sharpe Mfg. Co., Machinery and Tools, no. 136 (Providence, R.I., 1916), 537–539; Brown & Sharpe Mfg. Co., Small Tools Catalog No. 31 (Providence, R.I., 1929), 97; 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.
- Location
- Currently not on view
- Credit Line
- Gift of Margaret van D. Rice
- 1880–1892
- ID Number
- 1977.0460.06
- accession number
- 1977.0460
- catalog number
- 336077
- Object Name
- rule, triangular
- scale rule
- Physical Description
- steel (overall material)
- nickel (overall material)
- Measurements
- overall: 1.3 cm x 31.2 cm x 2.4 cm; 1/2 in x 12 9/32 in x 15/16 in
- place made
- United States: Rhode Island, Providence
- See more items in
- Medicine and Science: Mathematics
- Science & Mathematics
- Scale Rules
- National Museum of American History
- Subject
- Mathematics
- Drafting, Engineering
- Record ID
- nmah_904520
- GUID (Link to Original Record)
- https://n2t.net/ark:/65665/ng49ca746a7-2909-704b-e053-15f76fa0b4fa
