Getting Lambert's circles straight - Season Dial

[Deamicis-Roberts]

In the implementation of the season dial, "linear approximation"  is <4 cm over the course of the year,  and will probably be plotted with the EQT.   So, I think we are covered for accuracy to a reasonable degree with the 'Lambert's circles' data for sunrise/set times. Not only is it easier to see the data extrapolated from straight lines,  the season dial also tells the date. The Oostwal, Ootmarsum dial needs a "small equatorial dial" to get the correct date. It's got a bad GUI. (Maybe that comment is a little off key.)      The season dial version does not require that, since the date can be observed at "twilights". Better GUI. The idea was influenced by a paper that Roger supplied me with on medicine wheels... and some tequila. Mike  36.9151 : -121.3539   ----- Original Message ----- From: Martha A. Villegas To: Relojes de sol Lista Sent: Friday, January 11, 2002 8:29 PM Subject: RV: Seasonal Sunrise Marker       You can see two examples of  analemmatic sundials with these marks, at the Frans Maes page:   http://www.biol.rug.nl/maes/zonnewijzers/en/slyk-ewyk-e.htm   http://www.biol.rug.nl/maes/zonnewijzers/en/ootmarsum-e.htm   ...and also a link with a very good math page related with this. See:   http://pass.maths.org/issue11/features/sundials/   Greetings,   Martha A. Villegas   25°32' N 103° 27' W