Hi Mac, I once wrote a program Foster, not completed to the end but a sun compass is included. The output file may be used as input for ZW2000. I think I sent it to you. If not, ask me and I will do so.
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: "Fer J. de Vries" <[EMAIL PROTECTED]> Sent: Friday, February 04, 2005 5:29 PM Subject: Re: azimuth diagram > > Hi Fer, > > I think I remember that one of your programs draws a sun compass, but > can't remember which one. Help? > > Best wishes, > > Mac > > > > > > > > > >Hi Frank, > > > >You are constructing a sun compass with the Weir diagram, based on the > >analemmatic sundial. > >A lot has been written about. > > > >Have a look in Compendium, september 2003 for the article > >>From Universal Analemmatic To Sun Compass - Filling The Gaps > >by Frederick W. Sawyer > > > > > >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: "Frank Evans" <[EMAIL PROTECTED]> > >To: "Sundial" <[email protected]> > >Sent: Thursday, February 03, 2005 10:18 PM > >Subject: azimuth diagram > > > > > >> Greetings fellow dialists, > >> > >> The other day I bought a copy of Weir's Azimuth Diagram. This was the > >first > >> time I had seen it although I had read about it in earlier days. It is a > >> remarkable document, devised by Captain Weir in 1890. Its purpose is to > >> enable a navigator to find the azimuth of a heavenly body by graphical > >> means. > >> > >> In appearance it is a circle of 50 cm diameter on paper, containing a > >> central vertical ordinate, a series of concentric ellipses and mirrored > >> hyperbolic curves spreading from the central ordinate. It makes a very > >> pretty picture and is in colour. The diagram is entered with the elements > >> latitude (expressed as an ellipse), declination of the heavenly body > >> (expressed linearly on the vertical ordinate) and the hour angle (crudely, > >> sun time) of the heavenly body (expressed as a hyperbolic curve). Marking > >> the declination on the vertical ordinate (which is pricked out in degrees > >> from 65N to 65S) and joining this point to a second point where the > >> appropriate latitude ellipse crosses the hour angle hyperbola gives a line > >> which plots the azimuth of the heavenly body in question. > >> > >> It occurred to me that this graphical method of solving azimuth problems > >> could be modified to make a sundial. If the Weir diagram were to be > >levelled > >> and oriented N and S and a vertical shadow pin were placed on the central > >> ordinate at the sun's declination then the shadow would represent its > >> azimuth. Follow this until it reaches the appropriate latitude curve and > >> read off the time from the conjoined hour angle curve. > >> > >> Two points (1) This diagram is a fascinating survival, last printed in > >1950 > >> and still obtainable from UK Admiralty chart agents. It is catalogued as > >> chart no. 5000 and is printed on good quality chart paper. It costs 5 > >pounds > >> 50. There is a second diagram available for the hardy ones, extending from > >> 65 deg to 80 deg. > >> > >> (2) Have I got all this right? Is anyone else familiar with Weir's diagram > >> and has it been mentioned before in this sundial group? > >> > >> Frank 55N 1W > >> > >> - > > > >- >
