ce
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.

[Illustration: 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.

[Illustration: Fig. 390.--The Three Parts, with Sizes marked.]

[Illustration: 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 illustrated
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.

[Illustration: Fig. 392.--Chinese Cross Puzzle.]

[Illustration: Fig. 393.--Method of Putting Together.]

[Illustration: 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 sket