Design of a steel head-frame
An engineering thesis by Djalma Downey Williams, submitted in 1907 at the University of Illinois, working out the structural design of a steel head-frame for a mine shaft. The plates are hand-drawn in ink: stress diagrams and truss outlines with member forces lettered in by hand, plus force polygons labelled with loads in pounds, giving designers spare linear geometry, handwritten numerals and annotated technical lettering.
