New York [etc.] Simmons-Boardman Pub. Co. [etc.] · leaf 220
its ofEnglish and American built engines. The accompanying sketch illustrates a convenientmethod of showing the manner in which tracingsprepared for blue printing are sectioned and treatedin draughting offices. The outer blank circle is leftopen for colors corresponding with the inner shadedparts… … MACHINE BOLTS. O O TAP HOLTS. piece for those unfamiliar with the symbols of thedrawing room. Mr. A. Wankel,mechanical draughts-man of Chicago, designed this neat little device.His symbols, both in form and color, are closely inaccord with accepted standards, if indeed it is safe tosay that there…
Railroads · Railroad cars
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