Mechanical drawings: Many years ago I upset the head space experts. They insisted head space was identified and located with a line, they even had an arrow pointing at the line identifying the line as head space.

I insisted the datum was a round hole and on a drawing it was a circle I even wasted my time telling them about the story of the Duke that gave away some of his Dukedom for anyone that could solve his riddle. I recreated the riddle and introduced it to one of the biggest high schools in Texas. They all failed.

F. Guffey