Cased Instruments, ContinuedExtension barsExtension bars extend the range of a compass so you can draw larger circles.Care for an extension bar as you would any other cased instrument.Figure 2-27 shows a compass with and without an extension bar.Figure 2-27. —A. A standardlength compass. B. Astandard compass with anextension bar.BeamDraw an extremely large circle and arcs with a beam compass. The length ofcompassesthe beam that attaches the nibs and needle is the only limitation in the size ofthe radius of an arc or diameter of a circle. There are several styles andlevels of sophistication. Care for a beam compass as you would any othercased instrument.Figure 2-28 shows two types of beam compasses.Figure 2-28. —Beamcompasses.2-26
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
