Hi Allan, Yes there is. The old Roman surveyors used 3 shadowpoints of a vertical (pin) gnomon to find the east-west line, thus also the nort-south line is known. It is even possible to construct a sundial on any flat plane with only the knowledge of these 3 shadowpoints. It isn't necessay to know the latitude or the orientation of the plane. I wrote an article (in Dutch ) about this method in the bulletin of De Zonnewijzerkring, nr. 4, 1999. This article is based on a publication in French on the Internet by Yvon Massé. http://www.union-fin.fr/usr/ymasse Title: Comment tracer un cadran solaire incliné et declinant a l'aide de trois observations d'ombres inégales.
Best wishes, Fer. Fer J. de Vries [EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E ----- Original Message ----- From: Allan Pratt <[EMAIL PROTECTED]> To: Sundial Mailing List <sundial@rrz.uni-koeln.de> Sent: Friday, September 08, 2000 5:34 AM Subject: Meridian Line Question > Hello, > All dialists know, I'm sure, of the verical-stick, strike and arc, > bisect the angle method of determining a north-south line. > > But is there any other method of doing so which does not require some > additional data, like date, time, or something similar? Or is this the > only known way of doing so without external data? > > Al Pratt >
