298, A, and not at an angle as in B.The joining of the back will then offer little difficulty.

The principal difficulties lie in the facts that for comfort and appearance the back of the chair should incline backward both above and below the seat, and that the back of the seat should be narrower than the front.

By keeping at right angles to the floor the part of the back legs which receives the seat rail, the side seat rails will meet the back legs at a right angle in a side view, Fig.298.The back legs should be slightly shorter than the front legs, as shown in D.
[Illustration: Fig.298.Chair Construction.] The second difficulty involves the making of inclined mortise-and-tenon joints, A, where the side rails fit into the legs.
The making of these can be facilitated by laying out a plan of the full size and taking the desired angles directly from that.

It is common to reinforce these joints with corner blocks glued and screwed in place as shown in A.If there are additional rails below the seat rails, the easiest way to fit them in place is first to fit and clamp together the chair with the seat rails only, taking pains to have all angles perfectly true, and then to take the exact measurements for the lower rails directly from the chair.

The same method may be used for laying out a stringer between the lower rails.
If it is desired to bow the rails of the back, which are above the seat rail, this can be done by boiling them in water for 30 minutes and then clamping them over a form of the proper shape, with a piece of stiff sheet iron on the outside, as in Fig.299.They should be thoroly dried in a warm place.