The painted steel gnomon is mounted on an existing solar panel utility pole at the Environmental Learning Center.
The gnomon's shadow crosses the dark brown line at noon Pacific Standard Time and the light brown line at noon Local Apparent Time, when the sun is due south. The layout of the lines is entirely site-specific. The separation between the lines shows the difference between solar time and clock time.
The center of the shadow of the elliptical portion of the gnomon is used for determining noon. The shadow of the ellipse at noon is more or less circular depending on the time of year.
The stones show where the shadow crosses the lines on the first day of each month, tying the clock into the calendar and the movement of the Earth around the sun.
installation step 1: locating the centerline of the gnomon on the pole
installation step 2: bolting the mounting bracket onto the pole
installation step 3: hanging the gnomon from the bracket
installation step 4: pivoting the gnomon into position
installation step 5: pivoting the gnomon into position
installation step 6: seating the gnomon in the bracket
installation step 7: bolting the gnomon to the bracket
installation step 8: laying out the lines on the ground, using string and a giant protractor to mark where the shadow falls on different dates based on the sun's elevation angle
installation step 9: determining the separation between the lines, using another protractor to measure azimuth angles
installation step 10: construction of the lines using weed control fabric and landscaping bark