The Ten Books on Architecture Part 11

FORUM AT POMPEII

A, Forum. B, Basilica. C, Temple of Apollo. D, D', Market Buildings. E, Latrina. F, City Treasury. G, Memorial Arch. H, Temple of Jupiter. I, Arch of Tiberius. K, Macellum (provision market). L, Sanctuary of the City Lares. M, Temple of Vespasian. N, Building of Eumachia. O, Comitium. P, Office of the Duumvirs. Q, The City Council. R, Office of the Aediles.]

6. But basilicas of the greatest dignity and beauty may also be constructed in the style of that one which I erected, and the building of which I superintended at Fano. Its proportions and symmetrical relations were established as follows. In the middle, the main roof between the columns is 120 feet long and sixty feet wide. Its aisle round the s.p.a.ce beneath the main roof and between the walls and the columns is twenty feet broad. The columns, of unbroken height, measuring with their capitals fifty feet, and being each five feet thick, have behind them pilasters, twenty feet high, two and one half feet broad, and one and one half feet thick, which support the beams on which is carried the upper flooring of the aisles. Above them are other pilasters, eighteen feet high, two feet broad, and a foot thick, which carry the beams supporting the princ.i.p.al raftering and the roof of the aisles, which is brought down lower than the main roof.

[Ill.u.s.tration: _From Durm_

PLAN OF THE BASILICA AT POMPEII]

7. The s.p.a.ces remaining between the beams supported by the pilasters and the columns, are left for windows between the intercolumniations. The columns are: on the breadth of the main roof at each end, four, including the corner columns at right and left; on the long side which is next to the forum, eight, including the same corner columns; on the other side, six, including the corner columns. This is because the two middle columns on that side are omitted, in order not to obstruct the view of the p.r.o.naos of the temple of Augustus (which is built at the middle of the side wall of the basilica, facing the middle of the forum and the temple of Jupiter) and also the tribunal which is in the former temple, shaped as a hemicycle whose curvature is less than a semicircle.

[Ill.u.s.tration: VITRUVIUS' BASILICA AT FANO]

8. The open side of this hemicycle is forty-six feet along the front, and its curvature inwards is fifteen feet, so that those who are standing before the magistrates may not be in the way of the business men in the basilica. Round about, above the columns, are placed the architraves, consisting of three two-foot timbers fastened together.

These return from the columns which stand third on the inner side to the antae which project from the p.r.o.naos, and which touch the edges of the hemicycle at right and left.

9. Above the architraves and regularly dispersed on supports directly over the capitals, piers are placed, three feet high and four feet broad each way. Above them is placed the projecting cornice round about, made of two two-foot timbers. The tie-beams and struts, being placed above them, and directly over the shafts of the columns and the antae and walls of the p.r.o.naos, hold up one gable roof along the entire basilica, and another from the middle of it, over the p.r.o.naos of the temple.

10. Thus the gable tops run in two directions, like the letter T, and give a beautiful effect to the outside and inside of the main roof.

Further, by the omission of an ornamental entablature and of a line of screens and a second tier of columns, troublesome labour is saved and the total cost greatly diminished. On the other hand, the carrying of the columns themselves in unbroken height directly up to the beams that support the main roof, seems to add an air of sumptuousness and dignity to the work.

CHAPTER II

THE TREASURY, PRISON, AND SENATE HOUSE

1. The treasury, prison, and senate house ought to adjoin the forum, but in such a way that their dimensions may be proportionate to those of the forum. Particularly, the senate house should be constructed with special regard to the importance of the town or city. If the building is square, let its height be fixed at one and one half times its breadth; but if it is to be oblong, add together its length and breadth and, having got the total, let half of it be devoted to the height up to the coffered ceiling.

2. Further, the inside walls should be girdled, at a point halfway up their height, with coronae made of woodwork or of stucco. Without these, the voice of men engaged in discussion there will be carried up to the height above, and so be unintelligible to their listeners. But when the walls are girdled with coronae, the voice from below, being detained before rising and becoming lost in the air, will be intelligible to the ear.

CHAPTER III

THE THEATRE: ITS SITE, FOUNDATIONS AND ACOUSTICS

1. After the forum has been arranged, next, for the purpose of seeing plays or festivals of the immortal G.o.ds, a site as healthy as possible should be selected for the theatre, in accordance with what has been written in the first book, on the principles of healthfulness in the sites of cities. For when plays are given, the spectators, with their wives and children, sit through them spell-bound, and their bodies, motionless from enjoyment, have the pores open, into which blowing winds find their way. If these winds come from marshy districts or from other unwholesome quarters, they will introduce noxious exhalations into the system. Hence, such faults will be avoided if the site of the theatre is somewhat carefully selected.

2. We must also beware that it has not a southern exposure. When the sun shines full upon the rounded part of it, the air, being shut up in the curved enclosure and unable to circulate, stays there and becomes heated; and getting glowing hot it burns up, dries out, and impairs the fluids of the human body. For these reasons, sites which are unwholesome in such respects are to be avoided, and healthy sites selected.

3. The foundation walls will be an easier matter if they are on a hillside; but if they have to be laid on a plain or in a marshy place, solidity must be a.s.sured and substructures built in accordance with what has been written in the third book, on the foundations of temples. Above the foundation walls, the ascending rows of seats, from the substructures up, should be built of stone and marble materials.

4. The curved cross-aisles should be constructed in proportionate relation, it is thought, to the height of the theatre, but not higher than the footway of the pa.s.sage is broad. If they are loftier, they will throw back the voice and drive it away from the upper portion, thus preventing the case-endings of words from reaching with distinct meaning the ears of those who are in the uppermost seats above the cross-aisles.

In short, it should be so contrived that a line drawn from the lowest to the highest seat will touch the top edges and angles of all the seats.

Thus the voice will meet with no obstruction.

5. The different entrances ought to be numerous and s.p.a.cious, the upper not connected with the lower, but built in a continuous straight line from all parts of the house, without turnings, so that the people may not be crowded together when let out from shows, but may have separate exits from all parts without obstructions.

Particular pains must also be taken that the site be not a "deaf" one, but one through which the voice can range with the greatest clearness.

This can be brought about if a site is selected where there is no obstruction due to echo.

6. Voice is a flowing breath of air, perceptible to the hearing by contact. It moves in an endless number of circular rounds, like the innumerably increasing circular waves which appear when a stone is thrown into smooth water, and which keep on spreading indefinitely from the centre unless interrupted by narrow limits, or by some obstruction which prevents such waves from reaching their end in due formation. When they are interrupted by obstructions, the first waves, flowing back, break up the formation of those which follow.

7. In the same manner the voice executes its movements in concentric circles; but while in the case of water the circles move horizontally on a plane surface, the voice not only proceeds horizontally, but also ascends vertically by regular stages. Therefore, as in the case of the waves formed in the water, so it is in the case of the voice: the first wave, when there is no obstruction to interrupt it, does not break up the second or the following waves, but they all reach the ears of the lowest and highest spectators without an echo.

8. Hence the ancient architects, following in the footsteps of nature, perfected the ascending rows of seats in theatres from their investigations of the ascending voice, and, by means of the canonical theory of the mathematicians and that of the musicians, endeavoured to make every voice uttered on the stage come with greater clearness and sweetness to the ears of the audience. For just as musical instruments are brought to perfection of clearness in the sound of their strings by means of bronze plates or horn [Greek: echeia], so the ancients devised methods of increasing the power of the voice in theatres through the application of harmonics.

CHAPTER IV

HARMONICS

1. Harmonics is an obscure and difficult branch of musical science, especially for those who do not know Greek. If we desire to treat of it, we must use Greek words, because some of them have no Latin equivalents.

Hence, I will explain it as clearly as I can from the writings of Aristoxenus, append his scheme, and define the boundaries of the notes, so that with somewhat careful attention anybody may be able to understand it pretty easily.

2. The voice, in its changes of position when shifting pitch, becomes sometimes high, sometimes low, and its movements are of two kinds, in one of which its progress is continuous, in the other by intervals. The continuous voice does not become stationary at the "boundaries" or at any definite place, and so the extremities of its progress are not apparent, but the fact that there are differences of pitch is apparent, as in our ordinary speech in _sol_, _lux_, _flos_, _vox_; for in these cases we cannot tell at what pitch the voice begins, nor at what pitch it leaves off, but the fact that it becomes low from high and high from low is apparent to the ear. In its progress by intervals the opposite is the case. For here, when the pitch shifts, the voice, by change of position, stations itself on one pitch, then on another, and, as it frequently repeats this alternating process, it appears to the senses to become stationary, as happens in singing when we produce a variation of the mode by changing the pitch of the voice. And so, since it moves by intervals, the points at which it begins and where it leaves off are obviously apparent in the boundaries of the notes, but the intermediate points escape notice and are obscure, owing to the intervals.

3. There are three cla.s.ses of modes: first, that which the Greeks term the enharmonic; second, the chromatic; third, the diatonic. The enharmonic mode is an artistic conception, and therefore execution in it has a specially severe dignity and distinction. The chromatic, with its delicate subtlety and with the "crowding" of its notes, gives a sweeter kind of pleasure. In the diatonic, the distance between the intervals is easier to understand, because it is natural. These three cla.s.ses differ in their arrangement of the tetrachord. In the enharmonic, the tetrachord consists of two tones and two "dieses." A diesis is a quarter tone; hence in a semitone there are included two dieses. In the chromatic there are two semitones arranged in succession, and the third interval is a tone and a half. In the diatonic, there are two consecutive tones, and the third interval of a semitone completes the tetrachord. Hence, in the three cla.s.ses, the tetrachords are equally composed of two tones and a semitone, but when they are regarded separately according to the terms of each cla.s.s, they differ in the arrangement of their intervals.

4. Now then, these intervals of tones and semitones of the tetrachord are a division introduced by nature in the case of the voice, and she has defined their limits by measures according to the magnitude of the intervals, and determined their characteristics in certain different ways. These natural laws are followed by the skilled workmen who fashion musical instruments, in bringing them to the perfection of their proper concords.

[Ill.u.s.tration]

5. In each cla.s.s there are eighteen notes, termed in Greek [Greek: phthongoi], of which eight in all the three cla.s.ses are constant and fixed, while the other ten, not being tuned to the same pitch, are variable. The fixed notes are those which, being placed between the moveable, make up the unity of the tetrachord, and remain unaltered in their boundaries according to the different cla.s.ses. Their names are proslambanomenos, hypate hypaton, hypate meson, mese, nete synhemmenon, paramese, nete diezeugmenon, nete hyperbolaeon. The moveable notes are those which, being arranged in the tetrachord between the immoveable, change from place to place according to the different cla.s.ses. They are called parhypate hypaton, lichanos hypaton, parhypate meson, lichanos meson, trite synhemmenon, paranete synhemmenon, trite diezeugmenon, paranete diezeugmenon, trite hyperbolaeon, paranete hyperbolaeon.

[Ill.u.s.tration]

6. These notes, from being moveable, take on different qualities; for they may stand at different intervals and increasing distances. Thus, parhypate, which in the enharmonic is at the interval of half a semitone from hypate, has a semitone interval when transferred to the chromatic.

What is called lichanos in the enharmonic is at the interval of a semitone from hypate; but when shifted to the chromatic, it goes two semitones away; and in the diatonic it is at an interval of three semitones from hypate. Hence the ten notes produce three different kinds of modes on account of their changes of position in the cla.s.ses.

7. There are five tetrachords: first, the lowest, termed in Greek [Greek: hypaton]; second, the middle, called [Greek: meson]; third, the conjunct, termed [Greek: synemmenon]; fourth, the disjunct, named [Greek: diezeugmenon]; the fifth, which is the highest, is termed in Greek [Greek: hyperbolaion]. The concords, termed in Greek [Greek: symphoniai], of which human modulation will naturally admit, are six in number: the fourth, the fifth, the octave, the octave and fourth, the octave and fifth, and the double octave.

8. Their names are therefore due to numerical value; for when the voice becomes stationary on some one note, and then, shifting its pitch, changes its position and pa.s.ses to the limit of the fourth note from that one, we use the term "fourth"; when it pa.s.ses to the fifth, the term is "fifth."[7]

[Note 7: The remainder of this section is omitted from the translation as being an obvious interpolation.]

9. For there can be no consonances either in the case of the notes of stringed instruments or of the singing voice, between two intervals or between three or six or seven; but, as written above, it is only the harmonies of the fourth, the fifth, and so on up to the double octave, that have boundaries naturally corresponding to those of the voice: and these concords are produced by the union of the notes.