Greece, Ancient Greek Technology

Vertical sundial of southern orientation . Photo : Augusta Stylianou Artist


Vertical sundials of southern orientation

A vertical net orientated to the South with 13 engraved hours lines and three curves indicates from left to right (counter clockwise), with the help of the shadow trace from the horizontal (vertical to the net) gnomon tip, the 12 unequal (depending on the season) daily hours. The left horizontal hour line at the height of the gnomon indicates the sunrise, the right one indicates the sunset and the vertical one the midday. The closest curve to the gnomon indicates the course of the sun's shadow at the winter solstice, the most distant at the summer solstice and the middle straight line at the equinoxes.

Vertical sundial of southern orientation . Photo : Augusta Stylianou Artist