"Axis of the Sky"

Antonio & Teo Ros

This is a double sundial, polar and equatorial in Zaragoza, Spain. It is dedicated to the theme of the 2008 Zaragoza Expo, which is "Water".

You can see from the overhead picture that there is a pond to the west of the dial whose limit is the 10am marking as the expo opened at that time, and is delimited by two hyperboles corresponding to the opening and closing days of the expo. The tip of the shadow of the polar sundial enters the pond of water for the 93 days during which the Expo took place.

The sundial represents the energy of the water, because it is provided by the Sun. The polar sundial is highly accurate (less than 1 minute error) and tells the solstices, constellations (zodiac) and equinoxes at noon. In the image below right you can see the equatorial sundial at equinox.

The sundial shares the space with a natural undershoot waterwheel (noria) that works naturally and is the first 'engine' devised by mankind in this case to raise/lift water (2,200 years ago, in Mesopotamia). The noria was designed and made out of weathering steel, based on the original wood design by Syrian artisans.