3There are five species of courts; which receive their names from their forms. The Tuscan, Corinthian, the Tetrastylôn (with four columns), the Displuviatum (open at top), and the Testudinatum (roofed). The Tuscan cavædia are those in which the beams across the breadth of the court have trimmers (interpensivæ) to them, and valleys (colliquiæ) from the internal angles of the walls to the angles formed by the junctions of the beams and trimmers. Thus the rain falls into the middle of the court from the eaves of the rafters. In the Corinthian cavædium, the beams and uncovered middle of the court (compluvium) are as in the foregoing; but the beams around are detached from the walls, and rest on columns. The tetrastyle are those wherein columns are placed under the beams at the angles, which give strength and support to the beams; for thus they are not so liable to sag with their own weight, nor are they loaded by the trimmers.
2The displuviatum is that in which the water is carried off above the gutter plates (deliquiæ), which support the body of the roof. These are useful for winter apartments, because the compluvium being upright, the light of the triclinia is not obstructed. But they are constantly in want of repair; for the pipes which receive the water from the eaves being against the walls, and not capable of taking, at once, the water which should be carried off, it overflows from the check it meets, and injures the wood-work and walls in this sort of buildings. The roofed court is used when the span is not great, and large dwelling-rooms are made in the floor over it.
3The length and breadth of courts (atria) are regulated in three ways. The first is, when the length is divided into five parts, and three of them are given to the width. The second, when it is divided into three parts, and two are given to the width. The third is, when a square being described whose side is equal to the width, a diagonal line is drawn therein, the length of which is to be equal to the length of the atrium.
4Their height, to the underside of the beams, is to be one-fourth less than the length; the remaining fourth is assigned for the proportion of the lacunaria and roof above the beams. The width of the alæ, on the right and left, when the atrium is from thirty to forty feet long, is to be one third part thereof. From forty to fifty feet, the length must be divided into three parts and a half; of these, one is given to the alæ: but when the length is from fifty to sixty feet, a fourth part thereof is given to the alæ. From sixty to eighty feet, the length is divided into four parts and a half, of which one part is the width of the alæ. From eighty feet to one hundred, the length is divided into five parts, and one of them is the true width of the alæ. The lintel beams (trabes liminares) are placed at a height which will make the breadths and heights equal.
5The muniment-room (tablinum), if the width of the atrium be twenty feet, is to be two thirds thereof. If from thirty to forty feet wide, one half is assigned to the tablinum.From forty to sixty feet, the width is divided into five parts, and two given to the tablinum. The proportions of small atria cannot be the same as those of large ones; for if the proportions of the smaller be used in the greater, the tablinum, as well as the alæ, would be inconvenient: and if those of the larger be used in the smaller, their parts would be large and clumsy. I therefore thought it right to describe, with precision, their respective proportions, so that they might be both commodious and beautiful.
6The height of the tablinum to the beam is one eighth part more than the breadth. The lacunaria are carried up one-third of the width higher. The passages (fauces) towards courts which are on a smaller scale, are to be one-third less than the width of the tablinum; but if larger, they are to be one half. The statues, with their ornaments, are to be placed at a height equal to the width of the alæ. The proportions of the height and width of doors, if Doric, are to be formed in that method: if Ionic, according to the Ionic mode, agreeably to the rules given for doors in the fourth book. The width of the uncovered part of the atrium (impluvii lumen) is not to be less than a fourth nor more than one-third of the width of the same; its length will be in proportion to that of the atrium.
7The cloister (peristylium) is transversely one third part longer than across. The columns are to be as high as the width of the portico; and the intercolumniations of the peristylia are not to be less than three nor more than four diameters of the columns. But if the columns of a peristylium are of the Doric order, modules are taken, and the triglyphs arranged thereby, as described in the fourth book.
8The length of a triclinium is to be double its breadth. The height of all oblong rooms is thus regulated: add their length and breadth together, of which take one half, and it will give the dimension of the height. If, however, exedræ or oeci are square, their height is equal to once and a half their width. Pinacothecæ (picture rooms), as well as exedræ, should be of large dimensions. The Corinthian tetrastyle and Egyptian oeci (halls) are to be proportioned similarly to the triclinia, as above described; but inasmuch as columns are used in them, they are built of larger dimensions.
9There is this difference between the Corinthian and Egyptian oecus. The former has a single order of columns, standing either on a podium or on the ground, and over it architraves and cornices, either of wood or plaster, and a semicircular ceiling above the cornice. In the Egyptian oecus, over the lower columns is an architrave, from which to the surrounding wall is a boarded and paved floor, so as to form a passage round it in the open air. Then perpendicularly over the architrave of the lower columns, columns one fourth smaller are placed. Above their architraves and cornices they are decorated with ceilings, and windows are placed between the upper columns. Thus they have the appearance of basilicæ, rather than of Corinthian triclinia.
10Œci are sometimes constructed differently from those of Italy; the Greeks call them κυζίκηνοι. They face the north, with a prospect towards the gardens, and have doors in the middle. They are of such length and breadth that two tables (triclinia) with their accessories may stand in them opposite to each other. The windows, as well on the right as on the left, are to open like doors, so that the verdure may be seen through them whilst the guests recline on the couches. The height of them is equal to once and a half the width.
11In these apartments, convenience must regulate the proportions. If the windows are not obscured by high walls adjoining, they may be easily contrived. But if any impediment occur, either through nearness of adjoining buildings or other obstruction, some ingenuity and skill will be requisite to diminish or increase their established proportions, so as to produce a pleasing effect not apparently different therefrom.