Rolling Parallel Rule and Combination Instrument
date: label: date made
content: 1978–2012
notes: label: Description
content: This 12" clear plastic rolling parallel rule is combined with a scale of inches that is divided to 1/16"; a centimeter scale divided to millimeters; and a protractor divided to 5° and numbered by 30s from 0 to 90 to 0. Holes in the scales at every 1/2-inch and centimeter help the user align the instrument on a drawing. The holes may also be used with a pencil to produce parallel lines. The instrument is marked with a small centimeter-inch conversion table and the words: MADE IN TAIWAN.
label: Description
content: The white roller is also marked with various useful mathematical formulas, a small table of sines and cosines of various angles between 1° and 45°, and comparative centimeter and inch scales that function as a line spacing guide for measuring evenly spaced lines.
label: Description
content: The rule appears to be model 1205 of Hua Ching Manufacturing Co., Ltd., which has been making plastic and wooden drafting supplies in Taichung, Taiwan, since 1978. Several firms currently distribute the rule in the United States for a price of about $10.25.
label: Description
content: Reference: Hua Ching Manufacturing Co., Ltd., "About Us," http://www.taiwantrade.com.tw/huaching/home/en_US.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
label: Subject
content: Rule, Measuring
label: Subject
content: Protractor
label: Subject
content: Drawing Instruments
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: Parallel Rules
creditLine: label: Credit Line
content: Gift of Tony Brooks
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2013.0016.01
label: catalog number
content: 2013.0016.01
label: accession number
content: 2013.0016
objectType: label: Object Name
content: parallel rule
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Measurements
content: overall: 2.5 cm x 31.3 cm x 6 cm; 31/32 in x 12 5/16 in x 2 3/8 in