Complete Course: Millwork Drafting. E-book. Formato PDF Clarence Finley Mcgaughey   -  Forgotten Books, 2017  - 

No. 6. The key at the left of this lesson and directly below the 3 scale already explained is the key to the quarter inch scale. In learning the application of this scale, apply the method given above, governing the 3 scale only use the scale. The foot is divided into twelve equal parts or inches. The explanation in paragraph No. 3, will enable the student to apply any of the other scales of the scale rule, which are as follows'