Patent Model for Combination Rule, Protractor, and Calculating Device by Nels Ockerlund
date: label: date made
content: 1870
name: label: maker
content: Ockerlund, Nels
notes: label: Description
content: This combination instrument may be used to measure distances of up to 24 inches, to measure angles, to solve problems relating to ratios, to assist in finding the area of triangles when the lengths of three sides are known, and to add three-digit numbers. It is in the general shape of a four-fold rule, with a wooden core covered on both sides with German silver. A scale of inches, divided to 1/16" and numbered by ones from 1 to 12 twice, runs along the outer edges of the arms. Along the inner edges of both arms are scales of equal parts, with 30 parts to the inch.
label: Description
content: A protractor is at the center joint. A hollow in one arm contains two rules. One rule unfolds to reveal a 10" scale and a scale of 30 parts per inch. The other rule has a 4-1/2" scale and a scale of 30 parts per inch. These rules are supposed to attach to slides that move in a groove in one of the arms, allowing the solution of problems of proportion. To add numbers, one removes the longer rule from the groove, and places it alongside the scale on the arm.
label: Description
content: A third rule slides and pivots in a hollow in the other arm. Using this rule and the two arms of the instrument as sides, one can represent a triangle. The grooved arm serves as the base and a rule sliding in the groove measures the height of the triangle, from which one can calculate its area.
label: Description
content: The object is marked: Nels Ockerlund New York. Nels Ockerlund (1837–1903) was born in Sweden. He immigrated to the United States in 1865 and settled in New York City. In addition to the improved rule and calculator represented by this patent model, he took out a second patent in 1870 for an improvement in adding-machines. He became a citizen in 1879 and is listed in the 1900 census as still living in New York City.
label: Description
content: References: Nels Ockerlund, "Improvement in Rule and Calculator" (U.S. Patent 102,034 issued April 19, 1870), and "Improvement in Adding Machine" (U.S. Patent 105,717 issued July 26, 1870).
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, New York City
topic: label: Subject
content: Mathematics
label: Subject
content: Rule, Measuring
label: Subject
content: Protractor
label: Subject
content: Rule, Calculating
label: Subject
content: Patent Models
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Scale Rules
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.309330
label: catalog number
content: 309330
label: accession number
content: 89797
objectType: label: Object Name
content: scale rule and combination instrument
label: Object Name
content: rule
label: Object Type
content: Patent Model
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: german silver (overall material)
label: Measurements
content: overall: 3.2 cm x 17.7 cm x 4.4 cm; 1 1/4 in x 6 31/32 in x 1 23/32 in