Sérgio Garcia Doret wrote: > > Hello everybody > Where is the people of that list? Here is one person. > Can yon help me? I will try. > I plot a horizontal sundial for a place at lat 22º15'S and lon 42º > 7'W, > with longitude correction. I have calculated a declination line for july 15, > but > the curve was strange in relation to the solstice line.
How was it strange? The declination line for July 15 should not be too far from the summer solstice on a horizontal dial. Just about 10% closer to the equinox line. The longitude of the location will not change the "day line" but will shift the hour lines marked. It is kinda like declination effecta the "Y" plot on a plane and the hours and longitude effect the "X" direction. The two together determine one point made by a gnomon like the intersection of two lines. > I'm asking if that angular dfference must be considered (added) to > the sun's altitude angles in order to get correct results? I don't understand the question here. How did you get "angular distance"? Is this what you mean by correcting for longitude? If so, then there is more to it than adding to the sun's altitude. Do you mean by "correct results", the x,y plot of a point on a flat surface? > > Thanks in advance > > Sergio I hope this is a little helpful. Let me know. Happy Dialing, Warren Thom
