DOOR, a single piece, or assemblage of pieces, of wood, metal, stone or other material, supported movably in an opening, so as to allow or prevent passage through that opening. In door open ings of primitive huts sheets of hide or textiles were hung as doors. These were either hung as flaps or else arranged to roll up. In the tomb of Ti, in Egypt, of the 5th dynasty, there are elaborate wall-painting representations of doors of richly deco rated matting which were rolled up to the top, like an awning, to admit entrance, and in certain Italian churches to the present day similar flaps of leather are used as secondary doors. Doors of more rigid materials came into use early and consisted, apparently, of single heavy wooden boards, with pivots at the top and bottom of one side, fitted into sockets in the sill and head. This seems to have been the common practice in Egypt; when the doorway was wide, two such doors were used, pivoted on opposite sides.
In countries where wood was scarce, stone doors were used. This is notably the case in Syria, where many stone doors dating from the 4th to the 6th century have been found. Similar doors of stone or marble were frequent in tombs. There is a famous marble door from a tomb in Pompeii, probably of the Augustan era. These stone doors were always panelled, very likely to lessen the weight without reducing the strength.
In countries with damp climates, where single pieces of wood would warp, wooden doors are built up of several pieces, either by forming them of a series of vertical planks, tied together by tenons, dowels or horizontal braces known as battens, or else by forming a framework of uprights called stiles, and horizontal members called rails, with thinner panels placed between them and held in by grooves or additional mouldings. In Syria, Palestine and Mesopotamia wooden doors were frequently sheathed in sheets of metal richly repousse. In the British Museum there are numerous examples of the bronze bands decorated with pro cessions of figures and battle scenes and also the bronze pivots from the gates at Balawat (895-825 B.c.). These gates were of two leaves, each about 8ft. 4in. wide and 2 7f t. high, and the bands which decorated them are loin. high. Solomon's temple is described (I Kings vi.) as having doors of carved wood covered with gold leaf.
Classic doors were usually of wood, panelled. Representations in Pompeiian wall paintings and contemporary reliefs show that they greatly resembled the doors of the present day, and a plaster cast of an original charred door confirms this. These ancient doors seem to have been frequently in two, three or four leaves, and hinges connecting the leaves of such a door have been found. The doors for monumental buildings were largely of bronze (see BRONZE) and the beautifully designed example in the Pantheon (A.D. 110-125) is famous. Several similar Roman examples remain, especially those of the basilica of SS. Cosmas and Damian, in Rome, taken from an earlier building dating from the best Roman imperial period, and those of the Lateran basilica. The most im portant Byzantine examples extant are those of S. Sophia, Con stantinople. They are heavily panelled with deep mouldings and further enriched by rows of rosettes and decorative bolt heads. The influence of Roman precedent is obvious in the design. Many Romanesque bronze doors exist in south Italy. In these the panels are small, shallow and usually square. The richness is obtained through low relief that is sometimes scarcely more than engraving. The finest examples are those at Amalfi (Io6o), two at Troja (II19 and II24), that at Ravello (I179) and the doors of Trani cathedral (late 12th century).
Late in the i 2th century the pivoting of the doors at top and bottom gave way, generally, to the use of hinges ; this change offered great opportunities for door decoration which was repre sented in most of the important Gothic cathedrals. Here the doors are usually simple planked doors of wood, the decoration con sisting of the elaborate wrought iron hinge plates (see IRON IN ART) hammered into intricate foliated scrolls; occasionally, as in the famous doors of Notre Dame at Paris (early 13th century), additional cross braces of similar foliated wrought iron are in troduced among the three hinges. In the late Gothic period this usage died out. Decoration was obtained in the wood of the door itself by forming the panels with tracery, occasionally very intricately, and sometimes adding miniature buttresses and carved figures. In the smaller doors the use of the linen fold (simulating folded cloth) decoration is common. With the coming of the early Renaissance a similar kind of decoration was carried out with even greater richness, and wooden doors, in which panels crowded with figures, buttresses, simulated architectural f orms and decorated mouldings give an impression of extraordinary richness, are characteristic : e.g., the doors of S. Maclou at Rouen, by Jean Goujon, 154o. The later Renaissance returned to more classic and simple forms. Typical are the bronze doors of the Baptistery at Florence designed by Ghiberti (1402-52). Although in the north doors he followed the Gothic scheme of Andrea Pisano's south door, in the east, despite the complexity and beauty of the figure decoration, the scheme is rigidly rectangular. The use of rectangular or square panels remained constant throughout the Italian Renaissance, but in France, from the time of Henry IV. on, doors became more and more fantastic, culminating in those of the time of Louis XIV. and Louis XV., with their curved headed panels and double or triple mouldings.
In Muslim doors the enormous skill in elaborate wood framing possessed by Mohammedan carpenters finds congenial expression and the most intricate panelled types, with star-shaped and polyg onal panels, are common. Frequently additional decoration is given by complicated pierced and cut out metal mountings; some what similar mountings ornament the corners of the temple doors of China and Japan. These doors are usually of two panels, the lower solid, the upper filled with elaborate grill work in wood, either based on hexagonal patterns and triangles or an intricate network of straight lines of varying angles and lengths, over which paper is pasted in lieu of glass. In Japanese houses doors are usually sliding and may have the same pattern as the walls.
Modern wooden doors continue the traditional panel type. In construction, however, solid doors are more and more giving place to those in which a core of small pieces of soft wood is covered by sheets of veneers, enabling the occasional abandon ment of panels and the making of flush doors which are commonly used in hospitals. Another characteristic modern development has been the tremendous increase in the number and variety of metal doors in connection with fire-proof construction. These are of two types : metal covered or kalamein, in which a core of wood is covered with metal sheets, carefully soldered and locked to gether ; and hollow metal, in which a frame of structural metal sections is encased with metal plates. In both of these types, for structural reasons, the panel design is usually perpetuated, but flush pattern hollow metal doors are becoming more and more common. The use of top and bottom pivots instead of hinges is frequent in exterior doors, particularly where there are several doors in a row, in order to avoid vertical bars or mullions between them. Elaborate mechanical development of all types of locks, hinges, pivots, door checks and door closers is noteworthy. (See DOORWAY.) (T. F. H.)