TIL

[timelets]

Eupalinos [6th century BC] was the first hydraulic engineer whose name has been preserved. Armed only with intellectual tools, he pulled off one of the finest engineering achievements of ancient times. No one knows exactly how he did it.

http://calteches.library.caltech.edu/4106/1/Samos.pdf

also see https://en.wikipedia.org/wiki/Siloam_tunnel