There are several kinds of locks and fastenings in use, of which a few only can here be mentioned and none described. The former are fixed in or upon the lock rail, at a convenient height for the hand. The position for fastenings varies according to their description and the use for which they are intended.
For ledged, framed and braced, or other common doors, the only furniture required is a Norfolk or thumb latch and a rim lock. These are placed as shown on Figs. 497, 501, 502.
For superior doors, such as those in the principal rooms of good houses, mortise locks, concealed in the thickness of the door, with spring bolts and ornamental knobs, are chiefly used, and also finger-plates (fp), fixed just above and below the lock on both sides of the door (see Fig. 507). The lower finger-plate is very often made smaller than the other. The small bolt knob shown in this figure has gone out of fashion; when used its position varies. It is sometimes in a line with the large knob, or slightly above or below it, according to the make of the lock.
The edge of the keyhole is often protected by a brass plate or escutcheon screwed on over it, and having a hole in it a little larger than the keyhole. Dust and dirt are excluded by the use of a small hanging cover (see Fig. 507) pivoted above the keyhole.
For common or external doors heavier locks are required. These are generally iron-cased rim locks (see Figs. 504, 525), or for some doors wooden stock locks of an ornamental exterior are used.
External doors require to be further secured by barrel bolts, either horizontal, or (when hung folding) by vertical bolts at the top and bottom, sliding into the head and sill respectively (see Fig. 525).
Chain and barrel fastenings are also required on the inside of outer doors, in order that they may be secured when partially open. The plate at one end of the chain is screwed to the door frame, while a knob at the other end slides in a hollow barrel fixed to the door.
This is shown for the cross garnet hinges1 on the ledged doors in Figs. 497, 499, also for the hook and strap hinges in Fig. 501, and for the butt hinges2 in Figs. 504, 507, 525.
In framed doors the upper hinge is fixed on the edge of the style just below the level of the lower edge of the top rail, in order to be clear of the tenon of the rail; for the same reason the lowest hinge is placed just above the level of the bottom rail. When there are three hinges, the intermediate one is placed halfway between the others.
The knuckle of the hinge may be placed so as to coincide with the bead on the door-frame, as in Fig. 525. This is often done in good work to preserve the appearance of the bead intact, but a very general practice is to let half the knuckle into the door, as in Fig. 507, the remaining half being let into the frame.
To enter upon the different methods of fixing hinges would require long descriptions and diagrams; the subject is a somewhat intricate one, and does not form a part of this course.