In laying out rough stock, if the first edge is sufficiently straight, it is usual to thumb-gage for width. This is done by holding the pencil at the end of the rule and using the thumb of the left hand as the gage head, drawing the whole towards you with the rule acting as gage-beam. [Fig. 22].
Fig. 23.
A straight-edge, a board with a straight edge, is often used in marking out. Mark off the length of the piece of wood required. Mark off the breadth at the end of the board, also mark it near what is to be the other end of the piece. Place the straight-edge on these two marks and draw the line. [Fig. 23]. The try-square should be used to mark across the grain.
CHAPTER II.
Saws.
11. Saws.
—Saws which are used in cutting across the grain are called crosscut; those which are used in cutting parallel to the grain are called ripsaws. [Fig. 24]. Upon the blade of a saw, near the handle, will be found a number. This represents the number of points to the inch. Points should not be confused with teeth, for there is always one more point per inch than there are teeth.
Fig. 24.
To prevent the sides of a cut or kerf from binding the saw, the teeth are bent alternately from side to side, that the opening may be wider than the blade is thick. The saw teeth are then said to have “set.” To do good work, a saw should have no more set than is necessary to allow a free movement. [Fig. 25]. Damp, spongy lumber will require considerable set, while well seasoned lumber necessitates but little.