A textbook on mechanical and electrical engineering (1902)
International Correspondence Schools · Scranton : International Textbook Co. · leaf 14
nd edge ofthe board, as shown in Fig. 2. The upper edge C of theblade B is brought very near to the point through which itis desired to pass a line, so that the straight edge C of theblade may be used as a guide fpr the pen or pencil. It isevident that all lines drawn in this manner will be…
