A further variation of the puzzle is seen in Fig. 387. Here the joint is much simpler, and can easily be followed from the ill.u.s.tration.

[Ill.u.s.tration: Fig. 388.--Six-piece Joint Puzzle.]

CROSS PUZZLE.--Fig. 388 ill.u.s.trates a six-piece puzzle joint, similar in some respects to Fig. 369, but very much simpler. Both a back and front view of the piece D is shown for clearness of ill.u.s.tration. The method of a.s.sembling the pieces is as follows: Hold piece B upright, and fit piece D across; at the same time note that the small _x_ marks are opposite each other. Take piece E and, holding it as shown, slide it up the piece B (see arrow) until E engages D and the small _o_ marks are opposite each other. Piece C is now fitted behind D, and then piece F will slide in position and push downwards. The key-piece A is now put in position, and the puzzle is completed.

[Ill.u.s.tration: Fig. 389.--Mortising Puzzle, showing how the Parts Fit.]

MORTISING PUZZLE.--The ordinary mortising exercise is, after the first two or three attempts, generally voted as uninteresting, but, although the simple puzzle shown in Fig. 389 is practically an exercise in mortising, yet, forming as it does a puzzle, it becomes a fascinating piece of work.

The puzzle is composed of three pieces of wood, each 4 ins. long, 1-1/2 ins. wide, and 1/2 in. thick. In each piece a mortise 1-1/2 ins. by 1/2 in. should be cut as shown at 1, Fig. 390. In one piece, marked 2, a groove is cut on one side, 3/8 in. wide, and in another piece (3) a similar slot, but 1/2 in. wide, is cut, and this is continued on the other side of the groove to a depth of 1/8 in. The three pieces should be set out on a 13-ins. by 1-1/2-ins. by 1/2-in. length of wood, as shown at Fig. 391, and when ready sawn apart.

[Ill.u.s.tration: Fig. 390.--The Three Parts, with Sizes marked.]

[Ill.u.s.tration: Fig. 391.--How to Cut the Parts.]

The puzzle is put together as shown at Fig. 389. In the first place, hold No. 1 piece upright as shown at A, then take No. 2 piece with slot uppermost and push it through the opening in No. 1 piece until the nearest side of the slot projects 1/8 in. as indicated at B. Next place No. 3 piece on with the slot at the back as shown at C, and push it down until it touches the bottom of the opening in No. 2 piece as ill.u.s.trated at D. The only thing to do now is to push No. 2 piece as far as it will go to make the figure as shown at E.

In this puzzle the parts should fit together fairly tight, but should not be too stiff.

[Ill.u.s.tration: Fig. 392.--Chinese Cross Puzzle.]

[Ill.u.s.tration: Fig. 393.--Method of Putting Together.]

[Ill.u.s.tration: Fig. 394.--The Six Pieces, each 4 ins. by 1 in. square.]

CHINESE CROSS.--Fig. 392 shows a variation of the Chinese cross, which is perhaps the most fascinating of all woodwork puzzles. Take six pieces of hardwood (Fig. 394) and accurately plane and saw them so that each piece will measure 4 ins. by 1 in. by 1 in. Bearing in mind that all the cuts are multiples of 1/2 in., set out, saw and chisel five of the pieces to agree with the sketches 1, 1A, 2, 2A and 3. Leave the key piece intact.

The puzzle is of course to fit all the six pieces together so as to form the Chinese cross or block given at Fig. 392. As a clue to the method of a.s.sembly we give another sketch (Fig. 393) showing four of the pieces fixed together. The reader can, if he so desires, make the puzzle to a smaller scale by using six pieces of wood each measuring 2 ins. long by 1/2 in. by 1/2 in.

[Ill.u.s.tration: Fig. 395--Diagonal Chinese Cross Puzzle. (Two Pieces required of A, Three of B and One of C.)]

DIAGONAL CHINESE CROSS.--At Fig. 395 is given a sketch of a completed Chinese block or cross puzzle in which the various pieces of wood go together diagonally. Plane up a piece of hardwood (which may be about 14 ins. or 15 ins. long) so that it measures on its end 1/2 in. square. Cut the wood into six pieces which measure about 2-1/4 ins. long, and then proceed to mark out, saw and pare up with the chisel two pieces like sketch A, three pieces like B, and one key piece as C. Now fit these together to make the completed cross. The solution is left to the reader.

Fig. 396 shows a combination of six pieces which, when fitted together, will make the Chinese cross similar to Fig. 392. Plane up the strip of hardwood (birch preferred) so that it measures 1/2 in. square at the end and proceed to mark out and make two pieces like D, two like E, one like F, and one piece like G. Put the pieces together to form the Chinese cross. Again the reader is left to solve the problem of fitting.

[Ill.u.s.tration: Fig. 396.--Another Chinese Cross. (Two Pieces required of D, Two of E, and One each of F and G.)]

SQUARE PUZZLES are of endless variety. Four of these are shown, all simple to make, but not equally simple to solve. The only material required for each is a 5-ins. square piece of 1/8-in. fretwood or plywood; or, if preferred, pieces of different colour may be used. The diagrams are given exactly half size, and the lines may be set out direct on the wood. It will be noticed that all four puzzles are strictly geometrical in character.

[Ill.u.s.tration: Fig. 397.--Six-piece Square Puzzle. (For Guidance in Setting Out, the Centre of Top Line is marked at A.)]

[Ill.u.s.tration: Fig. 398.--Five-piece Square Puzzle. (In Setting Out, note that the Angles B B are Right Angles.)]

[Ill.u.s.tration: Fig. 399.--Ten-piece Square Puzzle. (For Guidance in Setting Out, the Centre of the Four Outlines are lettered at C, C, C, C.)]

[Ill.u.s.tration: Fig. 400.--Six-piece Square Puzzle. (The Centres of the Four Outlines are lettered at D, D, D, D.)]

Fig. 397 is made up of six pieces and is the simplest of the group to solve. Although containing only five pieces, Fig. 398 will be found to give more trouble.

Fig. 399, with ten pieces, is undoubtedly the most trying puzzle, and will be found as baffling as many jig-saw pictures. Fig. 400, again, presents only moderate difficulties.

If the reader prefers, he may cut the squares to the size ill.u.s.trated instead of enlarging them.

[Ill.u.s.tration: Fig. 401.--Blind Dovetail Puzzle Joint (see page 199).]