Bob, What a great dial. I have looked at the photos and have a few questions and comments.
It appears there is an upper half of the meridian as you said. I suspect this missing piece is the same shape and size (at least at its ends) as the lower half of the merdian. This is evident by how the raised edges of the casting do not go around the end. Rather then stop very abruptly as if it should continue on another piece. Also there is writing above the 0 degree mark that continues into the missing peice. What is the writing that appears at the top of photo 5? It may be a clue to the slide that you call "B". I don't think the "Hour Angle" is the same as the "Hour Angle Arc". It's easy to see how an arc that rotated about the polar axis, and had a hole in it perpendicular to the center of the globe, makes a sundial. We have seen this idea in a lots of dial with wires or pointer to the sun. However, that same hole could not be used to align with the horizon as stated in step two, because the globe would be in the way. The instructions only talks about a single pointer and a single timescale, The timescale seems to be the newly found part. For the "Hour Angle" and the "Hour Angle Arc" to rotate about the axis and tell time, it seems that the timescale has to be in a plane perpendicular to the axis. Perhaps as a ring at the bottom of the globe similar to the Longitude Scale at the top of it? Would you say the radius of the new peice is the same the meridian or the Longitude scale? If the slider B is on the meridian how does it affect the "Hour Angle" and the "Hour Angle Arc"? If the new piece is the timescale, would there be a need on the globe? Perhaps the new peice is a red herring left by the evil Dr. Moriarty. Hold on. I just looked at the Longitude ring in photo 4 and it has hours written on it. They appear to be the GMT offset for each timezone. ++ron -----Original Message----- From: Robert Terwilliger <[EMAIL PROTECTED]> To: Sundial Mailing List <sundial@rrz.uni-koeln.de> Date: Thursday, April 15, 1999 12:22 PM Subject: Unusual Sundial - Update >Dear Friends, > >Fernando Cabral visited the unusual sundial at Randolph Air Force Base in >San Antonio Texas recently, and returned with some new photographs, >including one showing the new broken part. > >The dial has been moved to a storage area, and it's future is questionable. > >The new photos can be seen at: > >http://www.shadow.net/~bobt/rafb/report > >The original (and obsolete) page can be seen at: > >http://www.shadow.net/~bobt/rafb > >Bob Terwilliger >Fernando Cabral > > >
