Dear Friends, With reference to the discussion of sundials for the use at the poles, I thought the group might be interested in the following Quiz from the North American Sundial Society's "Compendium". It has been edited slightly as it included a drawing when published.
The original quiz has lost some fascination as we already have some hints at the answer, but the "infinite number other locations from which the same itinerary could be completed" remains to be solved. ________ Q: A lady started from a certain point on earth. She walked south a mile, east a mile, then north a mile. She found herself back at the point where she started. When she arrived, she found some very interesting sundials. Can you describe any of them? (Submitted by Robert Terwilliger) -------- A: Fred Sawyer was the first to report that our adventuresome lady returned to the North Pole. Mac Oglesby was first to point out that there are an infinite number of other locations on the earth from which the same itinerary could be completed. I will leave their locations to you. The dials I thought were interesting were shown in a drawing. At the North Pole, a polar dial is also a vertical dial, and an equatorial dial is also a horizontal dial. An analemmatic dial will become the equatorial/horizontal dial. The familiar ellipse will become a circle, and the dateline will shrink to a point. At the North Pole the sun shines for only half a year, but once it rises, it shines all day until it sets. Many interesting variations on polyhedral dials that could accept 360 degrees of sunlight were suggested. Steve Woodbury opted to submit some designs for dials specifically for use at the poles. In one, the face is formed by a vertical cylinder with vertical hour lines around its circumference. The gnomons are four rods at the corners of a circumscribed square. A similar, but more elegant design uses a vertical solid with four symmetrical concave faces, each a quarter circle in plan and set at right angles to each other. The intersections of the faces provide the gnomons. Gnomonic Quiz #7 NASS Digital Compendium 2-4 December 1995 Best, Bob Terwilliger
