Hi All, To me the question is not more or less math, but how can certain concepts best be shown or learned. Fer de Vries had a set of steps to construct that helped me understand the eot. His hemispherium is also a construction that everyone should do. The math, like C=2(pi)r, has reasons behind them. Some relationships require the math. I like the variety of the Compendium - it has something for everyone.
More notes to follow: Roger Bailey wrote: > Hi John, > > At 09:15 AM 10/13/99 -0700, John Carmichael wrote: > > > >First, someone could write an article or series of articles on basic > >beginning trigonometry as it applies to dialing. > > Don't forget the quote from my old trig teacher, "All knowledge comes up > through a pencil." The best way to learn sundial trig is to do what you and > I have done. Work it through. Reading equations or hearing a lecture just > doesn't do it! > > >Secondly, I was surprised by how few professional full-time dial makers > >attended the conference. Maybe they weren't there because they don't exist. > >I saw a lot of dialing hobbiests with paper, plastic or wooden sundials. > > Your stone dial weighs over 400 lbs. The sun sculptures of Kate Pond and > Robert Adzema weigh megatons. Real dials are not that transportable > although I once finished a presentation by unveiling the Walking Shadow > dial, a 4' x 8' triangular piece of heavy composition board. It stole the > show but transporting it over 100 miles inside my VW Golf was a problem. > > Good to meet you at the NASS conference. Please continue to ask the > challenging questions. My challenge to all for today is to simply explain > the basic formula for horizontal dials: Tan HA = Sin L x Tan t. > There was a display of clear plastic triangles, ideal for an overhead, at the NASS meeting that did just that. I think it was Don Petrie that displayed them. I think he will sell a new set for around $70. Happy Dialling, Warren Thom (Lat=42n Long=88w) > > Roger Bailey > Walking Shadow Designs > N 51 W 115
