Dear John & All, Sorry for jumping in so late. I'm a little busy right now, but gave John's question and the responses a quick look.
I think you should NOT correct the latitude by the slope. The minor axis would get longer and the date line would get shorter when moving north (or the other way round for a southward move), whereas in principle you need to make both a little longer. VERY little, in fact: only 0.1% for a north-south tilt of 3 degrees, and only 1.5% for a 10% tilt. So, just forget about the slope correction and use the horizontal design for the actual latitude. Regards, Frans Copies to: "Frans W. MAES" <[EMAIL PROTECTED]> Date sent: Mon, 15 Apr 2002 09:15:46 -0700 From: "John Carmichael" <[EMAIL PROTECTED]> Send reply to: [email protected] Subject: Sloping Analemmatics To: "Sundial List" <[email protected]> > Hi All: > > I have a question. > > I use the Delta Cad macros to design analemmatics. These macros only > permit the design of analemmatics that have flat horizontal faces. But I > need to design an analemmatic that is painted on cement that slopes > slightly to the south. Let's say the angle of slope is 3 degrees from > horizontal and the latitude of the sundial is at 32.5 N.degrees. > > I thinking that if imput into the DC macro a false latitude of 32.5* - 3* > = 31.5 degrees that it would produce the correct drawing for the sloping > sundial. > > Is my thinking correct on this? > > Thanks anyone > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > > > - ===================================== Frans W. Maes Peize, The Netherlands 53.1 N, 6.5 E www.biol.rug.nl/maes/sundials/ ===================================== -
