Sundials - World's Oldest Clocks

North American Sundial Society

Tucson  

Sundial 825
State/Province:  Arizona Country:  USA
Dial Type:  Analemmatic Condition:  Excellent
Latitude:   32° 13.93' N Longitude:   110° 56.87' W
Location:
  • Located in front of the main entrance on the south side of Flandrau Planetarium and Science Center at The University of Arizona.
 
Description:
  • This nearly 14-foot wide analemmatic human sundial replaces the previous sundial at the same location. The previous dial by an unknown designer had several design errors and was in poor condition. The Flandrau Planetarium replace it, choosing a sundial with a blue background and white hour numerals. Dial Markings include quarter hour marks, Solar Noon Mark, Date Line with one week marks, Alignment Marker for Sunrise and Sunset (Bailey Points) with Solstice and Equinox lines, and the four Cardinal Points of the compass. The dial has a built-in longitude correction and shows Mountain Standard Time when readings are adjusted for The Equation of Time

    The overall width is 13 ft 8 5/8" The overall height is 9 ft 1 9/16". The width of the time mark ellipse is 10 ft 8". This was determined based on the average height of the adult American which is 5 ft 9". With this size ellipse, the shadow cast by the average adult American will reach the time mark ellipse on the summer solstice at Solar Noon.

    Dial markings were painted using stencils on a navy blue background on top of a new concrete surface. Extremely durable epoxy paint was used for the background and Rustoleum spray paint for the markings. Ellipses were drawn using the string and focus method. North was determined using a plumb bob string's shadow at Solar Noon. Design work was done using Delta Cad and Fer de Vries DeltaCad macro.
 
General Information:
  • Owner: University of Arizona
  • Designer: John Carmichael
  • Builder: John Carmichael and Rich Watson
  • Construction Date: June 27, 2016
 

Last Revised: 2016-07-05 23:34