The “shepherd’s” or “p
The dial is operated by turning the handle at waist height, which is connected to the 20-inch-(50 cm)-long gnomon above, until the gnomon’s shadow falls directly downwards; the gnomon is then pointed to the azimuth (compass direction) of the sun. One then reads the time and date from the position of the spot of sunlight (created by a slit at the end of the gnomon) as it falls on the side of the dial. The network of hour and date lines has been created by attaching 60 panels to the bronze cone; the edges of these panels define the lines. The Copernican motto for this dial is: Who’s turning?
In a portable pillar dial, the shape is cylindrical and the gnomon projects horizontally, but for aesthetic reasons this scaled-up version has a surface made from two cones and the gnomon points a bit downward. The University Prep dial also differs from the portable version in that, since it is fixed, we know where north is. Thus we can read not only the time, but the date, whereas the portable version requires the user to know the date beforehand, and then it can tell one only, say, that the time is 2 hours different from solar noon (10 am or 2 pm solar time), but not distinguish which one is correct!
There is also much dial “furniture,” including an indication of 2:40 pm Pacific Time, the time that school is out! Three of the 60 panels are made out of stainless steel; these mark the birthdays of the main designers. Tick marks at the top allow the azimuth of the sun to be read to a few degrees accuracy. The undulating line above the handle is based on the equation of time, although a more practical equation of time curve is provided on the explanatory plaque.
The north side of the dial features a puma (the school mascot) leaping through a large ellipse representing the orbit of Halley’s Comet. The orbit is used as a timekeeper to indicate the date of installation as well as the founding year of the school (1976).
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