Greetings, fellow dialists, Following the pictures of the fine dial of Frank King in Selwyn College, Cambridge (congratulations) I began to wonder how it was laid out. Most of the commonly consulted books on dial construction (in English), Waugh, Mayall & Mayall, Cousins, etc. do no more than glance at Italian and Babylonian hours. Only Rohr has some account. His practical method appears to be to find the time and nodus point of sunrise and sunset at the solstices, count the hours back from them and join the winter and summer nodus points for each hour. This seems a pretty journeyman’s procedure (nothing wrong with that) but I wonder if there is some more sophisticated method.
Also, the assumption seems to be made that sunrise and sunset occurs when the altitude of the sun’s centre is zero. This is far from sunset in any practical sense. Any comments, please? Frank 55N 1W --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
