A textbook on mechanical and electrical engineering (1902)
International Correspondence Schools · Scranton : International Textbook Co. · leaf 28
e usual flat andtriangular boxwood scales, having beveled edges, each ofwhich is graduated for a distance of 12 inches. The bevelededges serve to bring the lines of division close to the paperwhen the scale is lying flat, so that the drawing may beaccurately measured, or distances laid off… … 360 parts. Each division is one-half of one degree, and, forconvenience, the degrees are numbered from 0° to 180 from M. E. V.-3 18 GEOMETRICAL DRAWING §1 both A and B. The protractor is used for la)ing off ormeasuring angles. Protractors are often made of metal,in which case the central part is…
