Sundials on walls are common in Europe, but relatively unusual in North America. They are usually painted on walls and often have an associated mural. This wall dial, however, is made of pieces of metal mounted on the brick wall (actually, through the brick wall to the concrete wall behind it).
The initial idea for the dial came about through conversations between the architects for the Physics/Astronomy Building and Woody Sullivan, Professor of Astronomy. Mihaly Turbucz of Cesar Pelli’s architectural firm was the main architect involved. The dial was fabricated in the Physics Department Instrument Shop by Larry Stark. Sullivan was in overall charge of the project (1992-94) and did most of the design work.
The dial’s motto is What you seek is but a shadow. This was thought to be appropriate for a place of scholarship such as a university. On the other hand it was also felt that some acknowledgment should be made to the problematic aspects of a sundial located in Seattle, and so the plaque also has the ditty:
I thrive on the sun
Can’t work in the rain
So if I’m beclouded
Please come back again.
Besides its large size and accuracy, the dial is also unique in that its design in fact incorporates two dial planes. The shadow of the tube should be read on the brick wall, but the shadow of the ball is designed to be read on top of the metal surfaces (about 2-3 inches (5-7 cm) from the wall). The dial also has an interesting feature to protect the gnomon from oscillations that might be set up by high winds. The tube and the ball are each half-filled with mineral oil to dampen out any oscillations that might get started. (The chance of this is small, but real – remember that the famous Tacoma Narrows Bridge disaster in 1940 happened close to here!)