Sundials - World's Oldest Clocks

North American Sundial Society

Tucson  

Sundial 4
State/Province:  Arizona Country:  USA
Dial Type:  Equatorial Condition:  Fair
Latitude:   31° 57.597' N Longitude:   111° 35.890' W
Location:
  • Kitt Peak National Observatory Outside entrance to Visitor Center and Museum, about 56 miles west of Tucson on Highway 386
 
Description:
  • A bronze equatorial dial approximately 2 ft. in diameter designed by R. Newton Mayall. Mayall stated, "When I was asked to design the sundial in front of the Museum at Kitt Peak I was more than pleased, for it gave me a chance to work a semblance of astronomy into it. The design reflects the great telescope nearby, with its base and fork type mounting, the dial itself being the "telescope"."

    The dial surface is a half-cylinder whose inner surface has seven date lines and 15 minute apparent solar timelines. A thin rod supports a 1/4 inch spherical nodus in the middle of the sundial directly above the point where the 12 noon line crosses the equinox line. The shadow of the nodus tells both the apparent solar time and the date. The dial is in fair condition, with the brass gnomon rod and nodus sagging, giving rise to a noticeable error in time and date readings. There is a separate plaque in front of the dial that gives instructions for obtaining standard time using a table of the Equation of Time corrected for the dial longitude.
 
General Information:Inscription:
  • Owner: Kitt Peak
  • KITT PEAK
    LATITUDE 31? 57' 30".32 N
    LONGITUDE 111? 26' 22".72 W
  • Designer: R.N. Mayall
  • Builder:
  • Construction Date: Approximately 1972
 
References: Web Links:
  • Mayall, p.126, Mayall,"Sundials, Their Construction and Use" photo in Chapter VII. "'Dialing the Time", Sunworld, 4:3, 1980, p.109-113.
    Kitt Peak National Observatory is located on Tohono O'Odam Indian Reservation land.

Last Revised: 6/30/2012 22:27