Mac Oglesby recently asked: > >John Close has posted this message on the NASS Message Board: > >"Does anyone have any ideas for a Polar Dial which allows for an >Equation of Time adjustment. I would not like analemma shaped hour >lines as I think this would detract from the simplicity and >minimalistic quality of a Polar Dial. I am told an analemma shaped >gnomon for a polar dial would be hideously complicated and probably >not work . Any ideas anyone? John Close" > > >John has discussed this problem with several members of this list, >including me, Bill Gottesman, John Davis, and Pete Swanstrom. Some of >us think that a 3-D gnomon could be designed for use with straight >hour lines to correct for EoT, and some are skeptical.
As a Polar dial with an 'Oliver' type analemmical 'centrebody' is effectively a Schmoyer 'Sunquest' with the hour arc flattened out into a plate I don't seem to see any problem with this idea. Of course the Oliver device is symmetrical so the meantime correction would be only a close approximation. Of course it will suffer from the same problem all polar dials demonstrate viz. a shadow of increasing fuzziness away from Noon and problems with the early/late hours. Tony Moss P.S. Apologies for the delayed response but other problems have had my undivided attention recently. -
