beam compass

noun Drafting.

a compass having adjustable legs, set perpendicular to the paper and sliding along a horizontal bar so as to permit the drawing of large circles.

Origin of beam compass

First recorded in 1775–85

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Examples from the Web for beam compass

Historical Examples of beam compass

The beam-compass, Fig. 208, consists of two trammel-points running on a beam which may be made of any convenient length.
Handwork in Wood
William Noyes

British Dictionary definitions for beam compass

beam compass

noun

an instrument for drawing large circles or arcs, consisting of a horizontal beam along which two vertical legs slideAlso called: trammel

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012