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As the Sine of the Rhumb is to the Difference of Longitude; So is the Radius to the Distance run:
And
So is the Co-sine of the Rhumb to the Difference of Latitude.
So the Rhumb being E. N. E. 2 degr. 31 min. Easterly, and the Difference of Longitude 5 ½ degr. the Distance run will be found to be 117 Leagues, and the Difference of La∣titude 2 degr.
UPON the Point A protract an Angle of the Rhumb 70 degr. 1 min. and draw the Line A F. Then the Difference of Longitude being 5 ½ degr. count 5 ½ degr. upon the bottom of your Chart from A to G, and upon the Point G raise a Perpendicular G F, cutting the Line A F before drawn in F. Then the Line A F, being measured upon the Side of your Chart, will be found to contain 117 Leagues, the Distance run: And F G, there also measured, will be found to be 2 degr. the Difference of Latitude.