出版社：National Centre for Maps and Cartographic Heritage
摘要：Carte Pisane ( CP), the portolan chart known with this name since 19 th century, is co n- sidered by majority consensus as probably Genoese made and the earliest extant portolan chart of the Mediterranean Sea dated to the late - 13 th century, in High Middle Ages. This consensus is not yet based on solid certainty. As suggested by the map - reading theory of cartography the content of any map is constituted by two sets of 'cartographic elements', the geometric and the thematic , graphical ly represented on a material carrier (the vellum in this case), with toponymy being the fundamental element of the thematic set. A radiocarbon ( 14 C) analysis of the vellum has recently placed the CP ' s date between ca. 1170 to ca. 1270, whilst another rece nt dating based on toponymy proposed CP at a later period, in the 14 th century, as part (perhaps the earliest, with some doubts concerning the Crotona chart) of all the portolan charts of the Late Middle Ages. But what about the date of the second importan t constituent, i.e. the CP ' s geometric set, an element as fundamental as toponymy. To answer this question, we concentrate on the CP Coastline ( CPC ) in order to investigate the possibility of ge t- ting new insights on the CP dating question and affine issues . For this, we implement well - known comparative methods, known in geospatial engineering, for analysing the degree of CPC closeness or faraway from the actual coastline of the Mediterranean. The analysis shows a clear and consistent spatial pattern with h ighest degree of CPC closeness in areas of the central and eastern parts of the Mediterranean , seen with north upwards. This spatial resembling recalls the historical importance of these geographical areas during specific periods of the mid High Middle Age s associated, among other issues, with the strong antagonism s for the transition of geopolitical powe r between the old and new protagonists in that period and those areas. The concomitant historical events combined with the geometric results of the CPC anal y- sis indicate as a possible dating of its graphical representation the earlier limit of the time span estimated by the 14 C analysis, or even before. More importantly, however, they shed serious doubt to the opinio communis that the CPC also dates to t he late - 13 th century, or later, as this p e- riod is presumably closer to the CP toponymy and the vellum's date, ignoring in this complicated process the contribution of fundamental geometric cartographic elements, the CPC .
关键词：Portolan charts; coastline ; fitting; High Middle ; Ages
