Paragraph 24. In laying out the half-pitch cut (Chapter V, Paragraph 75) use the large steel square, as shown in Figure 40. Lay the square on the working face of the material in such a way that the same figure on the , blade and on the tongue are exactly even with the working edge of the material. Note: One side of a carpenter's square is 24 inches long - this arm is called the blade; the other arm is usually 16 inches long and is spoken of as the tongue. For illustration, if you take figure 12" on the blade of the square and make it exactly even with the working edge, also make figure 12" on the tongue of the square exactly even with the working edge. When the square is in this position you can mark along either the tongue or the blade and the angle will be exactly 45 degrees or the regular half-pitch cut. It does not matter what figures you use, but be sure you use the same figure on the blade and tongue, 4 and 4, 6 and 6, or any two numbers will give exactly the same angle.

Figure 40.