Concise 270 Circular Slide Rule
date: label: date made
content: 1959-1966
name: label: maker
content: Concise
notes: label: Description
content: This pocket-sized white plastic duplex circular slide rule has a clear plastic indicator that folds over the edge to serve both sides. It is held together with a metal pivot. The front base has L and D scales, with C, CI, A, and K scales on a sliding disc that fits inside the base. The center of the rotating disc is marked: CIRCULAR CONCISE SLIDE RULE (/) NO. 270 (/) MADE IN JAPAN. Near the center of both sides of the rule, the donor has scratched: SACK. The back base has DI and D scales, with S, T1, T2, and ST scales on the inset sliding disc.
label: Description
content: The instrument was received with a clear plastic sleeve, a black vinyl case, and an undated instruction manual. The sleeve is marked: Concise (/) No. 270. As of 2012, Concise continues to manufacture plastic circular slide rules, including models 28N and 270N. The company operated under the name Concise Co., Ltd., which appears on the instruction manual, from 1959 to 1966. The donor, Michael Sackheim, reported that he purchased this rule for calculating during his school days but got little use out of it.
label: Description
content: For other slide rules by Concise, see 1985.0636.02, 2003.0012.01, and 2006.0173.01.
label: Description
content: References: "Concise Circular Slide Rule," http://www.concise.co.jp/eng0731/circle02.html#02; accession file.
label: Location
content: Currently not on view
place: label: place made
content: Japan: Tōkyō, Tokyo
topic: label: Subject
content: Rule, Calculating
label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Science & Mathematics
label: See more items in
content: Slide Rules
creditLine: label: Credit Line
content: Gift of Michael Sackheim
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1996.0141.01
label: catalog number
content: 1996.0141.01
label: accession number
content: 1996.0141
objectType: label: Object Name
content: calculating rule
label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Physical Description
content: metal (part material)
label: Measurements
content: overall: .1 cm x 11.6 cm x 11.5 cm; 1/32 in x 4 9/16 in x 4 17/32 in