Sundials - World's Oldest Clocks

North American Sundial Society

Mount Laguna  

Sundial 170
State/Province:  California Country:  USA
Dial Type:  Equatorial Condition:  
Latitude:   Longitude:  
Location:
  • 50 mi. east of San Diego in the Cleveland National Forest at Mount Laguna Observatory. Sits beside the dome of the 21 inch telescope.
 
Description:
  • The odd bowl-shape of this equatorial dial designed and built by C.T. and W.M Thwaites shows a reversed engraved map of the world. A horizontal bar across the bowl has a small metal nib which points out the time of the day (top and bottom for standard and daylight times) and also indicates the spot on the world where the Sun is currently directly overhead. On full Moon nights, this dial has been used to effectively tell time and show the position of the Moon over the Earth as well.
 
General Information:Inscription:
  • Owner: San Diego State University
  • Charles M. Huffer. Pioneer in photoelectric photometry. U. of Wisconsin and San Diego St. U. Dial designed and built by C.T. and W.M. Thwaites 1892.
  • Designer: C.T. and W.M. Thwaites
  • Builder:
  • Construction Date: 1892