9Behind the scenes porticos are to be built; to which, in case of sudden showers, the people may retreat from the theatre, and also sufficiently capacious for the rehearsals of the chorus: such are the porticos of Pompey, of Eumenes at Athens, and of the temple of Bacchus; and on the left passing from the theatre, is the Odeum, which, in Athens, Pericles ornamented with stone columns, and with the masts and yards of ships, from the Persian spoils. This was destroyed by fire in the Mithridatic war, and restored by king Ariobarzanes. At Smyrna was the Strategeum: at Tralles were porticos on each side over the stadium, as in the scenes of theatres. In short, in all cities which possess skilful architects, porticos and walks are placed about the theatre,
2which ought to be constructed double, with their exterior columns of the Doric order, whose architraves, and cornices are to be wrought after the Doric method. Their width is to be thus proportioned: the height of the exterior columns is equal to the distance from the lower part of the shaft of the exterior columns to that of those in the middle, and from them to the walls which surround the walks of the portico is an equal distance. The middle range of columns is one fifth part higher than the exterior range; and is of the Ionic or Corinthian order.
3The proportions and symmetry of these columns are not to be guided by the rules delivered for those of sacred buildings. For the style used in the temples of the gods should be dignified; whereas, in porticos and similar works, it may be of a lighter character. If, therefore, the columns be of the Doric order, their height, including the capitals, is to be divided into fifteen parts, of which one is taken as a module. By this all the work is set out, making the thickness of the lower part of the column equal to two modules. The intercolumniation is of five modules and a half. The height of a column, exclusive of the capital, fourteen modules; the height of the capital one module, the width of it two modules and a sixth. The proportions of the rest of the work are to be the same as those described for sacred buildings in the fourth book.
4If Ionic columns be used, the shaft, exclusive of the base and capital, is to be divided into eight parts and a half, of which one is assigned to the thickness of the column. The base, with its plinth, is half a module high; and the formation of the capital is to be as shewn in the third book. If Corinthian, the shaft and base are to be the same as the Ionic; but the capital is to be proportioned as directed in the fourth book; and the addition on the pedestal is made by means of the scamilli impares, mentioned in the third book. The architraves, coronæ, and all the other parts, are set out in proportion to the columns as explained in the foregoing books.
5The central space between the porticos should be ornamented with verdure, inasmuch as hypæthral walks are very healthy; first, in respect of the eyes, because the air from green plants being light and volatile, insinuates itself into the body when in motion, clears the sight, and, removing the gross humours from the eyes, leaves the vision clear and distinct. Moreover, when the body is heated by the exercise of walking, the air, extracting its humours, diminishes corpulency, dissipating that which is superabundant in the body.
6That this is the case, may be proved by observing, that from fountains in covered places, or those which are under ground, no moist vapours rise; whilst in open places exposed to the air, when the rising sun darts his rays upon the earth, he raises the vapours from humid and marshy places, and, gathering them into masses, carries them into the air. If, therefore, in open places, the noxious humours of bodies are carried off by the air, as they are from the earth by means of clouds, there can be no doubt of the necessity of making spacious and pleasant walks open to the air in every city.
7That they may always be dry and free from mud, the following method must be adopted. They must be dug out and drained to the lowest possible level; and on the right and left sewers must be constructed; and in the walls thereof, towards the walk, drains are laid, with an inclination to the sewer. When this is done, the place is filled in with coals; over which the walks are strewed with gravel, and levelled. Thus, from the natural porosity of the coals, and the inclination of the drains towards the sewer, the quantity of water is carried off, and the passages remain dry and unaffected by the moisture.
8In these places the antients also made depôts for the reception of things necessary for the use of the city. For in case of the city being under blockade, all things are more easily provided than wood. Salt is with facility laid in beforehand; corn, from the public or private stores, is soon collected; and the want of that is remedied by the use of garden herbs, flesh, or pulse. Water is obtained either by digging new wells, or by collecting it from the roofs of buildings; but wood, which is absolutely necessary for cooking the food, is provided with difficulty and trouble; and that which is slowly procured is quickly consumed.
9In such times these walks are opened, and an allowance distributed to the tribes, according to their numbers. Thus they are conducive to two good purposes; to health in time of peace, and to preservation in time of war. If walks are provided after these directions not only behind the scene of the theatre, but also adjoining the temples of all the gods, they will be of great utility in every city. As they have been sufficiently explained, the method of arranging the different parts of baths will now follow.