Sundials - World's Oldest Clocks

North American Sundial Society


Sundial 351
State/Province:  Oklahoma Country:  USA
Dial Type:  Equatorial Condition:  Excellent
Latitude:   36° 23' 09" N Longitude:   97° 52' 54" W
  • Adventure Quest, 2nd and Maple. Inside the Adventure Quest compound, in back amongst the botanical garden. Access to Adventure Quest and the sundial is limited to business hours.
  • A striking stainless steel equatorial dial 6 ft tall, 4 ft wide, and 6 ft deep. The equatorial ring is more than 2 ft wide. The dial can be used as a simple equatorial dial, reading the hour from a shadow cast by the steel wire gnomon aligned to the polar axis. However a bead nodus located in the middle of the wire casts its shadow onto the equatorial ring as well. An analemma on an arched plate is set to slide along the equatorial ring in a track. By sliding the plate to a position where the nodus shadow falls on the analemma for the day of year, the dial corrects for the Eot. Markers on the analemma plate point to the correct time at the edge of the ring. The top of the ring is inscribed for Central Standard Time and the bottom is inscribed for Central Daylight Time. Overall, the sundial is accurate to about a minute any day of the year. The analemma was computed by Lt Col Bill Welker, USAF and the dial was funded by McCasland Foundation.
General Information:Inscription:
  • Owner: Leonardo's Science Center
  • Polar Analemmic Sundial
  • Designer: David A. Harbour
  • Builder:
  • Construction Date: 1997