Lining With Scriber And Try-Square. Through the points already placed, scribe lines, as ab, cd, etc., with the try-square.

Care must be taken that the advancing edge of the scriber is not turned out from the square blade; in such a case, it is likely to "run out" from the square and give a crooked line. Neither should the scriber be turned in so much as to crowd the square from its position. After a little practice, lines can be scribed easily and rapidly.