Safe-T Circle Perfect Compass

This instrument consists of two orange molded plastic discs held together by a metal screw and a plastic bolt, a blue pencil, and a blue plastic stylus with a metal point. The pencil and the stylus fit between the discs on opposite sides of the screw. The user adjusts the screw and stylus to the desired diameter for the circle, according to a scale from zero to ten inches on the front of the instrument or a scale from zero to 24 centimeters on the back of the instrument. The compass is somewhat flimsy to operate.
The front of the disc is marked: CIRCLE™ (/) PERFECT (/) #45748. The back is also marked: pat. pend. The stylus is marked: CHINA. A blue and orange cardboard backing was held to the instrument by the screw. The back of the card has instructions and is marked: Pat. Pend. (/) Made in China (/) SAFE-T PRODUCTS™, Inc. (/) P.O. Box 692 (/) LaGrange, IL 60625 [sic]. As with other Safe-T items in the collections, this model number was used for distribution to retail stores. Extra Measures, the company associated with Safe-T Products, sold this compass through its own catalog as model number 45743 for $2.25 around 2000. For company information, see 2000.0160.04.
References: Bruce Stoneberg, "Circle Compass" (U.S. Patent 5,630,278 issued May 20, 1997); accession file.
Currently not on view
Object Name
compass, drawing
date made
Safe-T Products, Inc.
Physical Description
lead (overall material)
wood (overall material)
plastic (overall material)
metal (overall material)
cardboard (overall material)
overall: 2.5 cm x 7.5 cm x 20.2 cm; 31/32 in x 2 15/16 in x 7 15/16 in
place made
Associated Place
United States: Illinois, Bensenville
ID Number
accession number
catalog number
Drawing Instruments
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Dividers and Compasses
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Extra Measures, Inc.
Additional Media

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