1797 XII. 693/1 The extent from 8 points to 3¼ points, the complement of the course on sine rhumbs.
1828 (ed. 20) 15 Sine rhumbs, marked (SR), is a line which contains the logarithms of the natural sine of every point and quarter point of the Mariner's Compass, figured from the left hand towards the right [etc.].