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    Re: Portuguese shipwreck question
    From: Frank Reed
    Date: 2009 Nov 2, 18:25 -0800

    John, you wrote:
    " The scatter plots were my first crude attempts to see if I could figure out 
    what these places corresponded to.   I didn't get as far as actually putting 
    onto a Mercator projection, however.   If you know of some software were one 
    can input these points onto a Mercator projection, that would be nice."
    Whoa there. WHY in the world would you want these positions plotted on a 
    Mercator projection?? The "scatter plot" you've made is just fine. All you 
    need is a base map on the same projection. Technically, a one-to-one lat/lon 
    projection is called "equirectangular" or "plate carre". There's a nice 
    Wikipedia summary here:
    What you need is a base map on the same projection. There are plenty of these 
    on the Internet. If you want a "better looking" projection for Europe and the 
    Near East/Middle East, you may want to look at a conic projection. But if 
    it's just for placing points in the right places on the map, there is no 
    reason to go beyond the equirectangular projection.
    I make maps of world history for a living in case you haven't followed up the 
    URL in my email address. See the "Centennia Historical Atlas" at 
    www.HistoricalAtlas.com. That's me. The projection in my atlas is conic.
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