Worthen, William Ezra, 1819-1897, [from old catalog] ed · New York, Appleton · leaf 64
n both sides, and DRAWING INSTRUMENTS. 47 graduated to four different scales. Sometimes the section of the scale is tri-angular (Fig. 144), with six scales on the different edges. To avoid confusion ylll 011^ Is 18 IL 19 .IS IJT IE \Z \l |0 MHIIIillllllllinilll l||!IIIIMIIIIII!lllinillllll|i|:|l… … Fig. 144.
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer04inte-127-42.webp)
