given length and the different widths arranged in columns; therefore, find either length in feet or width in inches under the 12-inch mark and follow this space until under the inch mark representing the other measurement. In this space will be found the feet board measure.

THE BRACE RULE

The brace rule is on the tongue of the square, and has a series of figures representing the rise or vertical height, the run or horizontal reach and the true length of a brace. For example, they are written 27/27 3819 and 4545 63 64. These would be read 27 inches run, 27 inches rise and a length of 38 and 19/100 inches, and 45 inches run, 45 inches rise and a length of 63 and 64100 inches.

A glance at the illustration on page 22 will give a good idea of the application of the brace rule as it appears on almost any modern make of square.

THE OCTAGON SCALE

There is an octagon scale on one side of the tongue of the square, but we will not attempt to explain its use, as there are easier and simpler methods of obtaining the same result.

One method is shown in Figure 1. To obtain the lines on a square stick where the corners should come when converted into an octagon or eightsided stick: Lay the square on the one side of the square stick at such an angle that the end of the square will come exactly at the edges or corners of the stick, make dot on the 7-inch mark and at the 17-inch mark. Through these dots gauge or mark a line parallel with the edge of the stick. Continue this operation on all of the four sides. This gives the lines for the corners of an octagon. In making a flag-pole or spar for a boat or to round any large stick this is the operation used by all mechanics doing the work by hand.

THE MITER BOX

Of all homemade devices, one of the most frequently used in the shop is the miter box. After

FIGURE 5A

the box is put together it is a simple problem, with the use of a steel square, to make the cuts necessary to intersect two pieces of wood, as shown in Figure 2. First, the box must be straight and true and the sides form a perfect right angle or square with the bottom. Lay the steel square on the top

of the box so that the 12-inch mark on the blade and the 12-inch mark on the tongue will both come

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FIGURES 2 AND 3

FIGURES 5 AND 4

This gives the angle of a perFigure 3 shows

exactly on the edge of the box. miter cut of the intersection of the fect square, as shown in Figure 2. the manner of placing the square on the box to give the desired angle.

A sprung molding, which is a molding not solid on the back, as shown in Figure 4, must be placed in the box bottom side up as shown in Figure 5, so as to get a solid bearing to hold it. Cuts in the box to miter around an eight-sided figure or an octagon, as shown in 5A, can be obtained by using 7 inches and 17 inches, marking the cut on the 7-inch side, as shown in Figure 5.

TRUING THE SQUARE

After obtaining a steel square, the first and most essential thing is to test or prove it to see that it is accurate, forming the angle of a perfect square.

Take a board planed on one side and straighten one edge of it perfectly as described under Making a Straight Edge. Make a mark across this board