In the US at least, the official times of sunrise and sunset for a particular city are for the population center of gravity of the city. It's a good bet that any atlas would use official government sources, and thus, the definition given above.
> ---------- > From: François BLATEYRON > Reply To: François BLATEYRON > Sent: Wednesday, August 25, 1999 3:59 PM > To: [email protected]; John Carmichael > Subject: Re: coordinates > > Hi John and everybody > > I can give some information about the coordinates of the cities included > in > my program Shadows. I took the coordinate from the "Grand Atlas de > geographie de l'Encyclopedie Universalis" published in France. In the > copyright notice they say that it is originally a book from Rand McNally & > Company. > > The coordinates are given for the approximate center of the town. In some > cases, they give the coordinate for another place near the town (i.e. the > Niagara falls: 43*15'N 79*04'W and Niagara Falls city: 43*05'N 79*03'W) > but > I included only the coordinates for the town. > > It can't be absolutely accurate, and may be I included also some typing > errors in editing the coordinates for the 750 cities by hand, reading the > book!! > > For Tucson, they only give 32*13'N 110*55'W. > > François Blateyron > EMail: [EMAIL PROTECTED] > Web: http://web.fc-net.fr/frb/sundials/ (cadrans solaires / > sundials) > > > > -----Message d'origine----- > De : John Carmichael <[EMAIL PROTECTED]> > À : [email protected] <[email protected]> > Date : dimanche 22 août 1999 21:57 > Objet : excuse me Fer > > > >p.s. > > > >I wrote to Fer pleading forgiveness for saying that his program contained > a > >list of cities with their coordinates. I was confused and should have > said > >that this program is from the "Shadows" program by Francois Blateyron . > But > >I'm still interested in knowing to which exact part of a particular city > >these coordinates apply and how these coordinates were selected. I guess > >I'll have to check out the mapblaster website to find out, now that I've > >made the creators of both these wonderful programs mad at me! > > > >John Carmichael > > > > > > >
