<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:303052240;
mso-list-type:hybrid;
mso-list-template-ids:-1836520274 134807575 134807577 134807579 134807567 134807577 134807579 134807567 134807577 134807579;}
@list l0:level1
{mso-level-number-format:alpha-lower;
mso-level-text:"%1\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level2
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level3
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level4
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level5
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level6
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level7
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level8
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level9
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear all,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have just registered as a member of this forum and cannot yet post directly, therefore an email to provide some initial answers.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>a)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Yes, I was awared the PhD degree by the university.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>b)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Regarding the availability of my thesis: I am trying to get a trade edition published, so for that reason the pdf file is not (yet) available.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span class=apple-converted-space><span style='mso-list:Ignore'>c)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]>Luis A. Robles Macias gives a good summaryof the press release, but one point is not correctly reflected: "they were much further advanced in terms of knowledge in the Middle Ages than we think". This is part of the following longer sentence: “<span style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#4C4C4C;background:white'>Nicolai concludes that part of history needs to be rewritten. "This needs to happen even if I am wrong, because that would mean that they were much further advanced in terms of knowledge in the Middle Ages than we think."<span class=apple-converted-space> </span></span><span class=apple-converted-space><o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>d)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Matthew Edney’s response is very much to-the-point. PR people indeed go for the spectacular and may even have a dislike for cautious wording! The numercial analysis of five charts (and the Compasso de Navegare) is only part of the thesis and indeed should never stand on its own. The historical context is absolutely indispensible. However I would like to reverse this statement: without taking into account the extraordinary geometric aspects of the charts a (purely) historical explanation of their origin and construction will not be adequate. <o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>e)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Joaquim Alves Gaspar states that the Mercator projection is old news, which it is. In 1987 Scott Loomer found that the Mercator projection is the projection that fits best to the charts but he analysed them as single charts. I analysed them as composite charts and found a mix of best fits to the Mercator projection and the Equidistant Cylindrical. This last type of projection features in the press release as “or similar type of projection”. Nevertheless, the (sub-)charts share more characteristics with the Mercator projection than with the Equidistant Cylindrical.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>f)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>I may have missed Ramon Pujades’ change of heart since his book “Les cartes portolanes” if he now favours the beginning of the 13<sup>th</sup> century. But unless he has uncovered something fundamentally new, I doubt that this has a serious impact the results of my study, but if it has, please let me know! Having a demanding full-time job I have concentrated the last few years on writing my thesis in the evening hours and weekends and as I am not part of the regular network of map historians I may have missed a few recent developments.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>g)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>I disagree with Gaspar’s conclusion that the magnetic declination of around 1200 is reflected in the charts and am certainly willing to discuss my reasoning. By the way, I (also) used the CALS7k.2 model, but evaluated it for 1250.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>h)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>The accuracy of the portolan charts is consistently high, but only if they are treated as composites. The high accuracy holds for any sub-chart, but the composite indeed reflects regional scale differences and orientation differences.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>i)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>The question whether the map projection is a deliberate part of their construction or just accidental (Gaspar’s portal entry) is not easy to answer, but is absolutely key to how we interpret those charts. The short answer is that I constructed three networks of bearings and (rhumb line) distances in the Western and Eastern Mediterranean and the Black Sea, based on what were likely routes to sail given the prevailing summer winds in these waters. I treated these ‘synthetic’ bearing and distance pairs as free from observational errors and processed the three networks as if the earth were flat, i.e. by plane charting. This resulted in a series of coordinates of the points of each of the three networks, obtained by plane charting and subjected each of the three plane charted network to the same cartometric analysis as I used for the portolan charts. If these networks naturally ‘contained’ the Mercator projection (or the Equidistant Cylindrical), the cartometric analysis process would yield a Mean Squared Error (MSE) very close to zero, i.e. a value small enough to ‘hide’ in the accuracy characteristics of the charts. This turns out NOT to be the case: the MSE ‘due to plane charting’ is close to or larger than the accuracy figure of the real charts. That is an algebraic impossibility. Ergo: the map projection is not an accidental by-product of plane charting.<o:p></o:p></p><p class=MsoNormal style='margin-left:.25in'><o:p> </o:p></p><p class=MsoNormal style='margin-left:.25in'>Best regards,<o:p></o:p></p><p class=MsoNormal style='margin-left:.25in'>Roel Nicolai<o:p></o:p></p></div></body></html>