Hi Mac et al, What I did is available for anyone who is interested.
A small executable basic program (with source code) for the method with hourlines 6 and 9 or 15 and 18. A small spreadsheet with the method Anselmo told us for input of two other hours. Send me an e-mail and I will send a zipped file of about 30 kB next week. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E ----- Original Message ----- From: "Mac Oglesby" <[EMAIL PROTECTED]> To: "sundial" <[email protected]> Sent: Friday, April 09, 2004 7:13 PM Subject: Re: Reverse Engineer Oldest SGS > > Hello John, Fer, Anselmo, Dave, et al. > > Please continue to cc messages to the Sundial List, so that we can > all share in this very interesting thread. I hope that some method is > worked out so that we can also access any drawings or pictures. > Thanks. > > Best wishes, > > Mac Oglesby > > > > > > > > >Hi Fer, Anselmo and others who gave mathematical formulas for > >reverse engineering: > > > >When I have time after Oxford, I am going to make a Delta Cad > >reproduction drawing of photo of the oldest SGS and I will indicate > >the hour angles of all the hourlines and the angle of the equinox > >line. > > > >Since I am not a good mathematician, I was wondering if I could then > >send you guys a copy of the drawing and you could use your > >formulas on it using my drawing. And I'll use the mathless trial & > >error method using Zonwvlak. Then we could compare the results. > >(latitude and wall declination). > > > >If it's as easy as Fer suggests, then it might be possible to make a > >program or spreadsheet that mathematically challenged people could > >use to analyze other dials with unknown latitudes and declinations. > > > >can we do this? > > > > (big snip) > > - > -
