line of, are two particular lines, so called on Gunter's sector. They lie between the lines of fines and superficies, and are numbered with 5, 6, 7, 8, 9, etc. They represent the diameter of a circle, divided into 100 parts, so that a right line drawn through those parts, and perpendicular to the diameter, shall cut the circle into two segments, the greater of which shall have the same proportion to the whole circle, as the parts cut off have to 100.