BALUSTERS are sometimes of real use, as in stairs, windows, terraces, and on the sides of passages open on one or both sides. At other times they are merely orna mental, as when terminating the upper part of the front of a building, as a screen to conceal the whole or part of a roof, or as a finish to insulated triumphal arches or gateways. They consist of short pillars, of a peculiar outline, standing upon a socle or plinth, and covered with a small cornice. No remains of balusters have been found in any ancient buildings. In the theatres and amphitheatres of the Romans, the pedestals of the up per orders were always continued through the arcades, and served as parapets. The lower seats, next to the arena in the amphitheatres, and those next the orchestra in the theatres, were guarded by a parapet called the podium. The top of the monument of Lysicrates at Athens is finished with a sort of parapet or ledge, com posed of honey suckles, solid behind, and open between every pier. Each plant is bordered with a curved head, and the bottom of every interval with an inverted curve. By impressions met with on coins, we are led to suppose, that terminations of the same kind were adopted in other Grecian edifices. Balustrades arc represented in the works of the earliest Italian writers, who might have seen them in the ruins of Roman structures ; but none have been discovered in modern times. When a balustrade finishes a building where an order is employed, its height should be proportioned to that of the order it accompanies, and must be raised on a socle or plinth, so that its parts may be completely seen at a proper distance. When in tended for service, it should be of equal height to a parapet in a similar situation, that is to say, not less than three, and not more than four feet six inches. In shape, the baluster consists of a square plinth, base mouldings, an ogee-shaped contour of body or middle part, an astra gal and cup, consisting of a moulding under a square abacus. The plinth of the base, the swell of the body, and abacus of the capital, are generally in the same ver tical straight line. The distance between the balusters
should not exceed half the breadth of the plinth, nor be less than one-third. On stairs and inclined planes, the same proportions are to be observed as on horizontal surfaces. Formerly the mouldings were made to follow the inclination of the plane ; but this is unpleasant to the eye, and is difficult in the execution ; indeed, in situations of this kind, the use of balusters have been generally superseded by ornamental cast-iron work. The breadth of the balusters over an order, must be regulated by the heads of the shaft of the column, to which the die of the plinth, the bulk of the body, and the abacus, must be equal. When there is no order, the breadth of the die of the pedestal is never more than its height, and fre quently less. The die of the pedestal is frequently flank ed by half dies, particularly when the range is long.
Doors, (see Plate CLXXXVIII.) in exterior walls, from apertures to gain an entrance into the buildings, or in interior walls for passing into apartments, or from one apartment into another. The former arc again distin guished by the terms door and gate ; a door is for the admission of men, a gate for horses and carriages ; and as well as to houses, are inlets to cities, fortresses, parks, gardens, Sze. Doors being of small dimensions, arc com monly parallelograms, either arched or covered horizon tally with lintels ; gates, being wider, arc, unless they consist of piers only, always covered with arches. The general proportions for the apertures of both gates and doors, is, that the height be about double the breadth.
For doors, the minimum apertures arc regulated that a man may pass easily through them ; they are, there fore, seldom less than three feet wide, and six feet six inches high ; but they arc often varied in their dimen sions, according to the height of the story and magni tude of the edifice. In private houses, four feet may be their greatest width ; in churches, &c. they arc fre quently six feet in width. In gates 8 or 9 feet is the least admissible breadth ; they are frequently from to to 12 feet.