Reacties
Ik heb niet meteen een antwoord paraat, maar bedoel je dit soort kaarten?
Het lijkt erop dat de lijnen verbindingen (richtingen) geven naar andere knooppunten waarvan (denk ik) de coordinaten goed bekend zijn. Het zijn geen kompaslijnen in de zin dat ze naar het magnetische noorden of zuiden wijzen.
Van https://en.wikipedia.org/wiki/Nautical_chart:
A bearing is the angle between the line joining the two points of interest and the line from one of the points to the north, such as a ship's course or a compass reading to a landmark. On nautical charts, the top of the chart is always true north, rather than magnetic north, towards which a compass points. Most charts include a compass rose depicting the variation between magnetic and true north.
En wat meer specifiek uit de Brittannica Encyclopedia: (https://www.britannica.com/technology/portolan-chart#ref241598)
Portolan chart, also called harbour-finding chart, compass chart, or rhumb chart, navigational chart of the European Middle Ages (1300–1500). The earliest dated navigational chart extant was produced at Genoa by Petrus Vesconte in 1311 and is said to mark the beginning of professional cartography. The portolan charts were characterized by rhumb lines, lines that radiate from the centre in the direction of wind or compass points and that were used by pilots to lay courses from one harbour to another. The charts were usually drawn on vellum and embellished with a frame and other decorations. Of the roughly 130 portolans surviving, most were made in Italy or Catalonia and a few in Portugal. The Italian portolans tend to encompass only western Europe and the Mediterranean basin, but some Catalan charts can be considered world maps.
Het lijkt erop dat de lijnen verbindingen (richtingen) geven naar andere knooppunten waarvan (denk ik) de coordinaten goed bekend zijn. Het zijn geen kompaslijnen in de zin dat ze naar het magnetische noorden of zuiden wijzen.
Van https://en.wikipedia.org/wiki/Nautical_chart:
A bearing is the angle between the line joining the two points of interest and the line from one of the points to the north, such as a ship's course or a compass reading to a landmark. On nautical charts, the top of the chart is always true north, rather than magnetic north, towards which a compass points. Most charts include a compass rose depicting the variation between magnetic and true north.
En wat meer specifiek uit de Brittannica Encyclopedia: (https://www.britannica.com/technology/portolan-chart#ref241598)
Portolan chart, also called harbour-finding chart, compass chart, or rhumb chart, navigational chart of the European Middle Ages (1300–1500). The earliest dated navigational chart extant was produced at Genoa by Petrus Vesconte in 1311 and is said to mark the beginning of professional cartography. The portolan charts were characterized by rhumb lines, lines that radiate from the centre in the direction of wind or compass points and that were used by pilots to lay courses from one harbour to another. The charts were usually drawn on vellum and embellished with a frame and other decorations. Of the roughly 130 portolans surviving, most were made in Italy or Catalonia and a few in Portugal. The Italian portolans tend to encompass only western Europe and the Mediterranean basin, but some Catalan charts can be considered world maps.
