Kidjel Ratio Cali-Pro Proportional Dividers
date: label: date made
content: ca 1962
name: label: maker
content: Kidjel, Maurice
notes: label: Description
content: This metal instrument has two long arms and two short arms, all colored gold and arranged as in a pantograph. Needle points are bolted to both ends of the long arms. The arms are fixed at a desired distance with a thumbscrew on a central rod. Unlike a pantograph or standard proportional dividers, the instrument is not marked so that it may be set for a variety of proportional relationships and thus be used to create scale drawings at a variety of sizes. Instead, the inventor, Honolulu portrait artist Maurice Kidjel (1888–1976), designed the instrument so that it always preserved a ratio of 5.333 : 1. To create drawings in this "universal ratio," the user set the long needles at the width of the large part of the drawing and then turned the dividers over to use the short needles to make a small part of the drawing in proportion to the large part of the drawing.
label: Description
content: A large white cardboard box is marked in maroon on the top and both ends: THE KIDJEL RATIO (/) CALI-PRO. According to a mark on the bottom, the box was manufactured by Christian & Co., Inc., of North Hollywood, Calif. Cardboard and yellow foam inside the box provided support and cushioning to the dividers and related documentation.
label: Description
content: Russian-born Kidjel and his business partner, Kenneth W. K. Young, began selling this device for $25.00 around 1960. According to the advertising flyer received with the object (MA.304213.04), the dividers were used only to lay out designs in the "universal ratio." However, Kidjel also believed that this ratio was the key to solving the three classic construction problems of Greek antiquity. His solutions, constructed with a compass and straight edge, appeared in the textbook distributed with the Cali-Pro (MA.304213.03). His work depended on a false definition of pi and thus is not mathematically valid. Nonetheless, Daniel Inouye read a tribute to Kidjel's ratio system into the U.S. <i>Congressional Record</i> on June 3, 1960. Although Kidjel's foray into mathematical proof was not successful, the dividers were relatively popular with draftsmen in the 1960s and 1970s. Kidjel was also widely respected as an artist, and his artwork was exhibited at the Smithsonian in June 1947.
label: Description
content: References: Maurice Kidjel, <i>The Two Hours that Shook the Mathematical World</i> (Hawaii Art Publishing Co., 1958); Maurice Kidjel and Kenneth W. K. Young, <i>Challenging and Solving the "3 Impossibles"</i> (Honolulu: Kidjel-Young Associates, [1961]); Advertisement for Kidjel Cali-Pro, <i>Art Education</i> 15, no. 4 (1962): 2; Maurice Kidjel, "Proportional Calipers" (U.S. Patent 3,226,835 issued January 4, 1966; UK Patent 1,039,636 issued August 17, 1966); Martin Gardner, "Mathematical Games," <i>Scientific American</i> 214 (June 1966): 116–122.
label: Location
content: Currently not on view
place: label: place made
content: United States: Hawaii, Oahu, Honolulu
topic: label: Subject
content: Mathematics
label: Subject
content: Drawing Instruments
label: Subject
content: Mathematical Cranks
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Dividers and Compasses
creditLine: label: Credit Line
content: Transfer from U.S. Department of the Treasury, Internal Revenue Service, Publications Department
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.333876
label: accession number
content: 304213
label: catalog number
content: 333876
objectType: label: Object Name
content: dividers
label: Object Name
content: proportional dividers
physicalDescription: label: Physical Description
content: cardboard (overall material)
label: Physical Description
content: metal (overall material)
label: Measurements
content: overall: 7 cm x 48 cm x 20 cm; 2 3/4 in x 18 29/32 in x 7 7/8 in