WE will now return to the box which we left unfinished in our thirteenth Lesson. We had got out the required material, cut it to the proper shape, and put it away to dry thoroughly. Examine the pieces carefully for shrinking, warping, and winding, and if necessary reduce them to their proper shape and dimensions. If they have shrunk or twisted much, it may be necessary to make them somewhat smaller than originally proposed, say 7/16" x 5 11/16" x 12 1/2" for the long pieces, and 7/16" x 5 11/16" x 7 3/4" for the short pieces; but it is to be hoped that this will not be necessary.

The four pieces for the sides are now to be put together with dove-tail joints as in Fig. 52, which is a working drawing showing five dovetailed tenons on each end of the long pieces A, which fit into five corresponding mortises in the ends of the short pieces B. The pieces which stand out between the mortises in B, and which might themselves be regarded as tenons fitting into mortises in A, are called "pins." The figures C and D show end-views of the pieces A and B respectively. The interrupted lines at A and B have the meaning already explained on page 2.

Fig. 52.

These drawings should be carefully studied till they are thoroughly understood. If they cannot be understood otherwise, you may examine a finished box and compare them with it. After this the work is to be laid out in the following way:

First, the lines a b are to be drawn with square and pencil on both sides of A, being careful, as before explained in similar cases,-to work from one edge and one face of the piece. Then the lines c d are to be drawn on the pieces B. Next set out on a b the eleven distances, of which those numbered 1, 2, 3, 4, 5 are equal, those numbered 6, 7, 8, 9 are also equal, and the two end spaces are half as long as 6 and 7.

When these spaces have been laid out exactly, the oblique lines from a b to e f can be drawn with the "bevel," provided e f is quite straight and square. The bevel must be first set to the proper angle. Take a smooth piece of board five or six inches wide, with one straight edge and one smooth face. The piece that you have used in previous exercises to place under your work to protect your bench will do very well. Near one end draw a fine pencil-line across it with your square. Measure from this line an inch along the edge of the board, and four inches along the line. Place your bevel with the handle against the edge of the board, set the blade so that the edge of it shall pass exactly through the two points thus determined, and clamp it. With the bevel thus set, placing it against the end of the piece A, you can mark first all the lines which slope in one direction, and then, turning it over, all those that slope in the other direction. They will appear as in Fig. 52 A. The dove-tails will be a little wider at the ends and will hold a little tighter, if the bevel is set with a slope of 3 1/2 to 1, or even of 3 to 1, instead of 4 to 1. This, however, will make the acute angles of the dovetails and pins weaker, and if the wood is soft they may break off at the edges. The work is sometimes laid out with smaller pins and wider dove-tails, as in Fig. 53 A. This lessens the amount of work to be done, but leaves the pins rather weak. If both the pins and the dove-tails are widened, as in Fig. 53 B, the work has the appearanc of too much sparing of labor. You may lay out, on the edges and ends of your piece of board sets of dove-tails with different angles and spaces, and compare them as to appearance and strength, and may select one for your work if you prefer to do so.

Exercise 31. Laying Out Dove-Tails

Fig. 53.

Having marked out the dove-tails on one of the faces of A, set the piece upright in the vise, and from the ends of the oblique lines draw fine lines with your square across the ends of the pieces. If the end is rough, you can make these lines clearer by first rubbing some chalk into the end-wood. After these lines are made, draw with the bevel, dovetails on the other face, to correspond with those already drawn on the first.

Next mark out the pin-pieces B. The drawing, Fig. 52 B, shows that side of B on which the pins are narrowest, which is the outside when the piece is in its place in the box. Lay the ends B on your bench with the other side, or inside, up, and lay out on c d the same distances that you have already marked on a b. Be very careful to have these distances exactly equal to those on a b. Applying the square to the end of B, draw lines through the points thus found, perpendicular to the end. Holding the piece upright in the vise, draw, with the bevel, lines on the end of B, corresponding exactly with those on the face of A, as in Fig. 52 D. Lastly, with the square, draw on the opposite face of B the lines perpendicular to the ends as in 52 B.

When you have marked out all the pieces, hold the end-piece B upright in the vise, the face B being turned towards you. Set A on B, the end IV turned from you, and assure yourself, by careful inspection, that the lines on the one piece correspond exactly with those on the other, so that there shall be no mistake when you begin to cut the pieces. Inspect the other corners in the same way. Mark the corners that are to go together, I, I, II, II; III, III; IV, IV. Mark the parts that are to be cut out as in Fig. 54. This will prevent the mistake, very common with beginners, of cutting out the wrong pieces.

Exercise 32. Dove-Tailed Box

With the fine back-saw, called "dove-tail saw," make all the cuts on the pin pieces, and then all the cuts on the dove-tail pieces, being careful in both cases to cut close up to the mark, but not beyond it. If this is skillfully done the pieces will fit together without paring. Then, laying the pieces on a clean board on your bench, cut out the waste-pieces as in the last exercise.

The points to be specially attended to are:

Not to cut a wrong piece.

Not to cut beyond the mark.

Not to drive the chisel too far perpendicularly before making an oblique cut (Fig. 51)

Not to cut quite through from one side, but to work from both alternately.

Not to let the corners of the chisel cut into the sides of the pins.

Not to drive the pieces violently together if they fit tight.

When the pieces are put together, every joint should be perfectly close, the ends of each piece should come just even or "flush" with the surface of the next, and the box should be perfectly square at all its corners, perfectly free from winding, and exactly of the proposed dimensions.

[The glue required for the next lesson should be partly prepared during this lesson.]