Hello all: I thought you'd be interested in seeing some sample fotos at of my equatorial heliochronometer featuring the bead-in-hole shadow sharpener that we've been discussing. Several images of this unique sundial can be seen on Dave Bell's website at: <http://dialist.webjump.com> Link to "Equatorial Heliochronometer by John Carmichael". (I just had to send you some fotos scanned on with my brand new Hewlett Packard ScanJet 5300C, which I love! Thanks for recommending it)
I designed and built this dial from scratch, by hand, and without computer assistance in 1995. I used red magogony and teak wood with brass trimmings. It has an interactive rotating alidade with analemma showing declination, EOT and dates every five days and the shadow sharpener nodus. The sundial is made for Tucson Arizona and shows Mountain Standard Time + or- 30 sec. The dial face is two feet across. It is based on a similar heliochronometer described in Mayall pages 193 to 200. I wanted it to look very "renaissance" so I included a lot of extras and a great deal of decoration. It features a solar azimuth scale, a magnetic compass (with cover), a plumb bob with cross wires and complete instrucions on the back. There are also declination and EOT tables. The time and solar azimuth are read by first turning the alidade until the shadow falls on the proper date. There are two tight thin wires (which don't show up well in the fotos) directly over the time and azimuth scales. One wire is directly above the other on the nodus side of the alidade and are parallel to the dial face. Two wires are needed to avoid paralax reading errors. When the two wires are lined up visually, the time and azimuth can be read on the dial face directly below. The face background color is painted emamel with lots of 24K gold leaf! I drew the hour lines with a ultra fine point "Sharpee" pen. I used clear sticky back for the numerals and lettering. The face has 26 coats of very thin polyurethane with 1500 grit wetsandings between coats. Needless-to-say, it took an entire summer to build and it's been very sad to see it degrade and self-destruct over the years. People say it should be in a museum instead of outside. In fact, watching it ungracefully age convinced me to switch to stone sundials and to never again waste my time with wood. At least it will survive in photos. I'd love to see someone else build a similar one in metal (hint Tony and Bill). I've only seen similar dials as pocket versions. I hope to soon post more detailed photos my device at better resolution on Dave Bell's Website. Will let you know. best, John Carmichael Tucson Arizona http://www.azstarnet.com
