Drafting room methods
A 1918 manual of drafting room practice by Charles Dickey Collins, issued in New York by D. Van Nostrand for machine draftsmen and engineering offices. The plates are line drawings and shaded engravings of pipe fittings, threaded bolts, tees and crosses, shown in plan and elevation with dimension arrows and letter keys, useful as technical diagram stock, industrial pattern fills, and lettered measurement callouts.
