Practical engineering drawing and third angle projection, for students in scientific, technical and manual training schools and for ... draughtsmen .. (1897)
Willson, Frederick Newton, 1855-1939 · Princeton, N.J., The author · leaf 159
is self-evident after what has preceded. On a larger scale the curva-ture of the helices would have to be indicated. The upper view is an elevation of a small double-threadedsquare screw, generated by winding two equal rectangles simul-taneously around the axis. The central figure is an elevation…
Mechanical drawing · Lettering
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
