Johnston, Philip Devereux, 1855- · New York, D. Williams Company · leaf 27
2 A MANUAL OF MECHANICAL DRAWING One Drawing Pen, 4^ or 5 inches long. One Triangular Scale 12 inches long, with divisionsin twelfths, those coated with white celluloid being thebest. J- … I One Protractor, 4-inch or 5-inch, of German silver,graduated to degrees or half degrees, to be used formeasuring and laying ofif angles. One Triangle 7 45°, of celluloid or rubber. OneTriangle 9 30°-6o°, of celluloid or rubber.
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
