Fig. 75 is an isometric drawing of a part of one of the stiles of the door, showing the mortise and the groove, and Fig. 76 is a similar drawing of the end of the rail or tenon-piece, turned round so that the shoulder A B is towards you, and the tenon C and the stud D are visible. From these drawings you will be able to understand the way of marking out this joint.

Fig. 75.

Fig. 76.

As the tenons are to project half an inch beyond the stiles, and as these are 2 1/2" wide, a mark is to be made first, all around each rail 3" from the end, and a second mark 10" from this, which will be 3" from the other end. These are the marks at A B, Fig. 76, which show the shoulder of the tenon.

Fig. 77.

They should be interrupted on the outer edge at the middle, as at D, so as to prevent the mistake of cutting across the stud when you begin to saw. Next the thickness of the tenon is to be marked with the gauge on the edges and ends of the rails as at E, always working from the front face. Then the breadth of the tenon is to be marked by drawing, with the gauge, lines 1/2" and 2" from the inner edge, being careful not to extend them beyond the cross lines at D and F. Lastly, the length of the stud D is to be marked with the square, and its breadth with the gauge. The marking will then appear as in Fig. 77. The marking out of the mortise is simpler, and is shown in Fig. 78. Light marks P Q may be made 3 1/4" from the ends of the stiles, which will be 15" apart, and will indicate the positions of the inner edges of the rails, or the inside length of the frame. Marks R S 2 1/2" from these will indicate the outside length of the frame. These should both be drawn light, as no cutting is to be done on either of them. They may indeed be omitted, though they serve as a useful check to prevent mistakes in laying out the rest. Marks on the inner and outer edges, 1/2" and 2" from P Q will show the length of the mortise; and gauge marks with the gauge set exactly as in drawing A B, Fig. 77, and measured from the front face, will show the width of the mortise. The marking will appear as in Fig. 78, in which the dotted lines are on the rear faces. The groove for the panel is not shown in these figures. It appears in Fig. 75; and the method of marking it out and cutting it will be shown in the next Lesson.

Exercise 37. The Paneled Door

Fig. 78.

The marking being now finished, the cutting out proceeds as follows: With the back-saw cut first the lines A B, Fig. 77, then the lines C D and E F, observing that C D must not be cut so deep as E F, in order to leave the stud L B uninjured. Next make the cross-cuts G H, I J, I K, and J K, being careful not to cut too deep. The side pieces will then fall off, leaving the tenon complete, except the stud L B. The stud is still of the same thickness as the tenon, and must be pared down to the proper thickness with the chisel, by taking off 1/8" from its back face, as shown in Fig. 77 and in Fig. 67 a. The tenon, also, will need some paring, if you have not cut exactly to the marks with the saw; but you must not in any case cut beyond the middle of the mark.

The mortise may be cut with the center-bit and chisel in the same way as in Lesson XV (The Chisel Continued)., page 89, or with the chisel alone. The breadth of the mortise being small and its depth considerable, the bit will be apt to mar the sides of the cut, unless it is held exactly perpendicular to the face of the piece and kept very steady. For this reason, and for the sake of practicing the other method, we will cut out this mortise with the chisel alone.

Lay the piece on your bench, with the edge up. To steady it, you may first lay a hand-screw on the bench, then set the piece in it and tighten the screw, as in Fig. 79. With alternate perpendicular and oblique cuts, as described on page 116, cut the mortise half-way through the piece. Then turn the piece over and cut in the same way from the other side. When the two cuts meet, the four surfaces are to be pared to the marks, using a wide chisel for the sides, and being careful not to cut away anywhere more than half the width of each mark. If the paring of both pieces has been properly done, the tenon will fit closely in the mortise. If it fits so tightly that there is danger of splitting the mortise-piece, it must be carefully pared away a little more. The tenon cannot be driven quite "home," being stopped by the stud. Room will be made for this by cutting the groove, which is the next operation.

Fig.79.