Public Sundial

If I had three wishes, one of them might be to create the public sundial I once designed for the North American Sundial Society (published in The Compendium in March 2001). Here is a crude diagram. Most public sundials drift more than fifteen minutes during the course of a year, which is just no good. My design has no drift, and an accuracy to within one minute. A tilting, reflective surface at hip height (A) reflects sunlight up a hollow, swinging gnomon (B). The sunlight is reflected back down the gnomon, to fall on the correct time (C). OBSERVATION: In principle, it is called a collimating altitude dial, although it looks nothing like it. I designed other versions of the same, among them a souvenir wrist watch which would have an accuracy to within five minutes.