One of the "engines" episodes mentioned means ancient Greeks made starting of foor races
fair. The "aphetes" = starter, operated a "hyslex" = starting gate" which was a clever device
which used same mechanism as a catapult to whip the starting rope barrier out of the way
of the runners, who had to have both feet in a shallow gutter called "balbis". But the site
says there was a manhole for the starter. I couldn't figure out why that was necessary.
Can you?
http://ist-socrates.berkeley.edu/~cls180/week3/menu3.html