The Greeks and Romans relied on wat

The Greeks and Romans relied on water clocks and sundials, the descendants of great obelisks that the Egyptians built in the desert sun of the pharaohs, close to the equator. The hours of the day were inscribed in a great perimeter about their base. But as can be imagined, obelisks and sundials were of little practical use for much of the year in northern Europe, where the shadows (when the sun was not obscured by clouds) grew long and the daylight fleeting in the autumn and winter.