I've always been interested by the κλεψύδρα, water clock. Searching that term now brings up hourglasses, which is a connection I've surprisingly never made.
And specifically Ctesibius' one, <a href="https://en.wikipedia.org/wiki/Ctesibius" rel="nofollow">https://en.wikipedia.org/wiki/Ctesibius, which is an analog computer for calculating the time.
Rendello · · focus · HN ↗
<a href="https://en.wikipedia.org/wiki/Water_clock" rel="nofollow">https://en.wikipedia.org/wiki/Water_clock
pseudohadamard · · focus · HN ↗