Bracewell described the sundial in the March 1997 issue of Stanford’s Civil Engineering Newsletter [http://www-ce.stanford.edu/Newsletter/archive/CENL0397.PDF ].  It is a vertical declining dial 15 degrees to the west, approximately 72 x 80 cm in size and made from aluminum  In a plaque prepared by Bracewell and installed beneath the sundial, he states that his dial was modeled after the vertical dials that still faintly adorn the Tower of the Agora in Athens.  The Tower of Agora, also known as the Tower of the Winds, was designed by Andronikos of Kyrrhos, and built in the early Roman period ~1^st century BC.

Instead of a typical gnomon, Bracewell chose to use an oculus: a disc with a central hole.  Standing 8 cm in front of the dial, the disc creates a shadow with a bright dot of sunlight in the center for telling both time and season.  The hour lines are offset by 2 min 40 sec to account for the longitude of the Stanford campus and the hour lines themselves are laid out not as straight lines, but as analemma curves (the figure 8 pattern of the sun’s seasonal movement), with spring colored in green, summer in red, autumn in orange, and winter in blue.  The analemma corrects for the “Equation of Time” allowing Bracewell to create an accurate clock-telling sundial.

The motto “Caelum Scruntando Leges Motus Didicmus” translates to “We learn the laws of motion by studying the heavens”.  And with a bit of subtle math, “d/dt ≠ 0” on the dial plate, one could interpret this to mean “Time changes all things”.  While Dr. Ronald N. Bracewell designed the sundial, his son Mark C. Bracewell constructed it.  Both their initials can be found at the bottom of the dial.

Need a small sundial for your display or science project?  Want to show how different sundials cast shadows?  Need a simple cut-out science exercise for your students?  Fabio Savian of Milan Italy has the solution.  For a number of years he has managed the Sundial Atlas website, ever increasing the number of sundial photos from around the world.  Over the last several years he has worked very hard to create the gnomolab that includes a solar compass map of the earth, cloud software for creating analemmatic (human shadow) sundials, and a section for making paper sundials to your specification.  The analemmatic dial measurements and papger dial designs are created as download PDF files.  Four of those dials were created by the North American Sundial Society.  Enjoy. Sundial Atlas Paper Sundials

The Planetary Society and Bill Nye, The Science Guy, are bringing back the Earth Dial, which is a simple to make gnomonic horizontal sundial reminiscent of the sundial incorporated into the Mars rovers Spirit, Opportunity and now Curiosity.  Their original and fundamental purpose is to serve as test patterns for the rover cameras, but they also provide an opportunity as unique shadow casting sundials.

“Since we had shadows being cast on Mars, I suggested it be a sundial… I admit I was quite enthusiastic about it. Steve Squyres, the Principle Investigator on the Spirit and Opportunity missions, made the call, and the Mars Dials were created. He received the [Planetary] Society’s Cosmos medal a few years ago, for his wonderful leadership of the project.”

 The Earth Dial project was started in 2004 and now, nearly a decade later, is being brought back.  Visit the Planetary Society website Planetary Society - Earth Dial for details and download the attachment below to construct your own Earth Dial.

Professor Dr. Susanne Bickel and her archeological team from the University of Basel found one of the oldest sundials in the world during this year’s excavation in the Valley of the Kings.  A limestone sundial was found near tomb KV61 during a survey of the surface rubble. The location of the dial corresponds to an area where there are remains of workmen’s huts dating to the Ramesside Period of the 13^th century BCE.

The dial was most likely a vertical, south facing sundial. The horizon line of the dial is about 16 cm across with a hole at the mid point to hold a simple horizontal metal rod or wood stick gnomon, indicating that the gnomon displayed shadows of temporal (seasonally uneven) hours. The limestone dial has a black painted semicircle.  On each side of the vertical noon line are 6 segments of about 15 degrees each, representing morning and afternoon temporal (seasonally uneven) hours.  Small dots in the middle of each hourly segment serve for even finer timing.  Nevertheless, the hour lines are not drawn with precision.

 The archeologists speculate that since the subdivision of the solar cycle in hours was a key aspect of depictions on the walls of the royal tombs where illustrated texts describe the nightly journey of the sun god through the underworld, the sundial could have supported the observations and visualization of this journey.  Or the sundial could have been used as a simple clock by the workmen that toiled away digging and decorating the Ramesside tombs.

 University of Basel News Release 14 March, 2013                              [photo courtesy of the University of Basel]

This year’s NASS Conference will be held Aug. 22-25, 2013 in Boston/Cambridge, Massachusetts at the Courtyard by Marriott. Be sure to mark your calendar for this special event celebrating the Society’s 20^th year.  Details on the cost of the conference and accommodations will be posted when details are finalized.

In a departure from the usual agenda of having a bus tour excursion of area sundials, on Aug. 23^rd members will focus on two exhibits at Harvard – the primary one being the exhibit “Time and Time Again” curated by Dr. Sara J. Schechner long time NASS member holding the position as the David P. Wheatland Curator of the Collection of Historical Scientific Instruments. Featured objects will include portable sundials and precision clocks, calendars from different cultures and epochs, time charts shaped like animals, Mesopotamian, Native American, and African ritual objects, fossils, and metamorphosing creatures.  Visit http://www.fas.harvard.edu/~hsdept/chsi_tta.html for more exhibit details.

NASS attendees can add their own outlooks on time and sundials by making presentations on the varied arts of sundials and displaying their creative works.  Contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it to sign up for presentations and display space.

[photo of the Lienhart Miller 1629 sundial from the CHSI by permission]