The Compass Rose

For centuries sailors found direction by the wind and often named winds by destination. Pliny wrote of sailing the 50 miles from 'Carpathus to Rhodes with Africus', Africus being the wind. The four cardinal winds were divided into 32 half and quarter winds, giving a course to within one point (11.25°). In the early 13th century, wind roses appeared on Portolan charts, with rhumb lines springing from wind roses in the centre, or around the edge of the chart.

Using winds for naming direction is fine if they are constant. Frisian navigators in North Europe, where wind direction varies hourly, called the cardinal points Nord, Ost, Sud and West and used compounds of these words for the intermediate compass points, creating the system we use today.

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