Dear Roger & All: Roger wrote: >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!
That is why it is important to include actual examples in a beginners' trig article. >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. The articles written us artists should not discuss our large heavy sundials as such, but should focus on the metalworking and stone carving techniques and tools that we use. These methods can certainly be used by the beginner to construct smaller dials. That is how I started. Over the years, I used larger and larger stones for my dials as my confidence and carving abilities improved. I bet Kate and Robert started out the same way. >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. Dittos on meeting you Roger! Thanks for the floppy disk of your talk. As for the above hour line formula, maybe the best way to teach the beginner its solution would be to pick an example latitude and print the pages of Natural Logrithrimic Functions from a typical trig table that have the desired values. That way, the beginner could see how to use the tables. Then using the proper values, plug them into the formula and voila, he gets the answer! Doing it this way, the beginner doesn't even need to know trig formulas, as basicly he is just following a recipe. The same teaching method can be used with almost any formula, even the advancd ones that appear in the Compendium. (a later article could show the beginner how to use a scientific calculator instead of a printed trig table) John Carmichael http://azstarnet.com/~pappas
