Fig. 7. Is a joint with concealed hinges intended for a door ; and here, as the door is sufficiently thick, the ends of the hinges are of equal lengths, and are concealed in the thickness of the wood.
Fig. 8. Is the method of hinging shutters in the common way, where the hinge is let its whole thickness into the edge of the shutter, upon the supposition that the inside lining would be too thin for the screws which are employed in fastening them, in order to have suffi cient hold.
Fig. 9. Shews the method of hanging a door with cen tres which are entirely concealed. Suppose a d that part of the side of the jamb which comes in contact with the edge of the door ; bisect a d in b, and draw b c perpendicular to a d; make b c equal to b a or b d, and join a c and c d; from c describe an ora a e d, which shows the part to be hollowed out of the jamb. The centres are fixed to the top or bottom of the door. The upper centre must be so constructed as to admit of being taken out of the socket, so that the door may be unhung, as may be required.
Fig. 10. Shews the method of hanging shutters in the usual way, where the centres of the knuckle of the hinge is placed exactly opposite to the perpendicular part of the rebate. The dotted lines show the flap exactly as folded hack.
Fig. 11. Shews how the hinge is to be placed when the axis of the knuckle cannot he placed opposite to the joint. Thus, let a b be the distance of the edge of the flap from the edge of the shutter ; bisect a b in c; then c is the point opposite to which the centre of the hinge must be placed. This situation for the knuckle of the hinge becomes neces sary, when the shutters are not square at the ends, or when the boxing-room is not sufficiently ample. The principle is, to place the centre of the knuckle of the hinge at half the distance of the edge of the flap from the rebate on the edge of the shutter.
Fig. 12. Shews the two parts as hinged together.
Fig. 13. When a door has a cornice, or other projecting moulding, and when it is required to bring the doors in a situation, when open, parallel to its place when shut, the knuckle of the hinge must he made to project as far, or something more, than the cornice or caging moulding.
This principle will be sufficiently evident by inspecting the figure. The dotted lines shew the situation of the door when folded back.
Fig. 14. Shews the form of a rule-joint, either for shut ters or furniture that require to open no farther than a right-angle, and that are to be exposed at the external angle. Here the centre of the hinge must obviously be in the centre of the arc.
Fig. 15. Shews the same when turned to a right-angle.
Shutters are always within the apartments, wherever beauty is aimed at ; those on the outside destroying the appearance of the front. They are divided into several ver tical slips folding behind each other, for the conveniency of concealing them within the thickness of the wall. Each slip or !Old is framed and composed of several panels, either raised or flat, surrounded with small mouldings contained within the thickness of the framing.
The case in which the shutters are enclosed, is called the boxing. The parts of the sash-frame in connection who the shutters, are the inside lining which forms one side of the boxing, and to which the front shutter is hung. The vertical piece of wood which adjoins the edges of the sashes and the inside lining, is called the pulley style. The vertical piece of wood which joins the pulley style on the outside, parallel to the inside lining, is called the out side lining. That side of the boxing which is parallel to the late of the shutter, is called the back of the boxing. Tht remaining- third side of the boxing is either formed by the architrave which surrounds the aperture within the room, or, in very good houses, by a groined flush on one side with the plaster of the wall. The parts of the sash frame which are parallel to the horizon, are the sill and top, which names bespeak the situation in which they are placed. Inside beads are those slips of wood, rounded on the edges, which form one side of the race or groove for the sashes to run in. Parting beads are those slips of wood which separate the upper and lower sashes.