Sundials - World's Oldest Clocks

North American Sundial Society

Building on the success of the 2010 USA Science & Engineering Festival, the North American Sundial Society and Analemma Society joined nearly 1500 other activities at the Expo in Washington DC on April 28-29, 2012 presenting "Sundials, the World's Oldest Clocks". That's the old news. The new twist is that Ken Clark of NASS made it to youtube describing sundials. You can watch too: