A textbook on mechanical and electrical engineering (1902)
International Correspondence Schools · Scranton : International Textbook Co. · leaf 29
d, 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 cut away to make thedrawing under it visible. When using… … Fig. ej For example, let it be required to draw a line throughthe point C, making an angle of 54° with the line £ F,Fig. 20. Place the protractor upon the line £F, as justdescribed, with the center O upon the point C. With asharp-pointed pencil, make a mark on the paper at the54 division, as…
