Johnston, Philip Devereux, 1855- · New York, D. Williams Company · leaf 27
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.
![An illustration from Works. Popular edition.] 2 series (1886)](https://img.insideoutlibrary.com/img/200/bl-bl_003191336_5-284-1.webp)
