Anselmo, I have no formula of the curve. I calculate such a dial by a series of points. Read the article in Compendium, bulletin of NASS that recently is published. Vol. 8, nr. 4, december 2001. Show me your formula, I am interested in it.
Best, Fer. ( no Frans ) Or did you want to write to Frans Maes? Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E ----- Original Message ----- From: "Anselmo PÈrez Serrada" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Sunday, September 08, 2002 10:42 PM Subject: On bifilar polar sundial > Hoi, Frans! > > I have been playing a bit with the equations for a bifilar dial trying to > reproduce the bifilar polar dial that I saw in your web. There you say > that the transversal gnomon is a piece of hyperbola, but I have found > that it is really a piece of ellipse (there are more solutions, but none > is an hyperbolic arc). I suppose my calculations are wrong but I can't > find the mistake in them. Can you please provide me more > information about this topic? Do you know the exact equation for this > curve? > > Hartelijke bedankt, > > Anselmo P. Serrada > > > > > - -
