When your divine intellect and majesty, Imperator Caesar, were taking possession of the empire of the world; when, with every enemy laid low by your unconquered valor, your fellow citizens were glorying in your triumph and victory, every subjugated nation awaited your nod, and the Roman People and Senate, released from fear, were guided by the amplest of your reflections and counsels: amid such pressing concerns I did not dare to publish my writings on architecture, long elaborated in great thought, for fear that, intruding at an unseasonable moment, I might incur the displeasure of your mind. §1
But when I observed that you cared not only for the common welfare of all and for the constitution of the commonwealth, but also for the fitness of public buildings, so that under your hand the State was not only enlarged by new provinces, but the majesty of the empire should also possess the outstanding dignity that public buildings confer, I judged the matter not to be passed over: at the very first opportunity I ought to set these things before you. And the more readily because I had first been known to your father in this regard, and was devoted to his valor. When the council of the gods had consecrated him among the seats of immortality, and had passed your father's imperium into your power, that same devotion of mine, abiding in his memory, conferred its favor upon you. And so it was that, together with Marcus Aurelius, Publius Minidius, and Gnaeus Cornelius, I stood ready for the preparation of the ballistae and the scorpions and for the overhaul of the other engines of war, and I received their benefits alongside them. These, once you had granted them to me at the outset, you preserved through the recommendation of your sister. §2
Since then I was bound by that benefaction, so that to the end of my life I should not fear poverty, I began to write these things for you, because I had noticed that you had built much, and build now, and in the time that remains will take care for both public and private buildings befitting the amplitude of your achievements, so that they may be handed down to the memory of posterity. I have drawn up defined prescriptions, so that by attending to them you may have knowledge, in the works both already accomplished and yet to come under your hand, of what kind they are. For in these volumes I have opened up all the principles of the discipline. §3
The architect's knowledge is adorned with many disciplines and varied learning, and by his judgment are proved all the works completed by the other arts. This knowledge is born of practice and reasoning. Practice is the continuous and well-worn consideration of use, by which with the hands something is wrought out of material of whatever kind, for the purpose of a given design. Reasoning, on the other hand, is that which can demonstrate and explain, by skill and the principle of proportion, the things so wrought. §4
And so architects who had striven without letters to be skilled in hand only could not bring it about that they should have authority to match their labors; while those who had trusted in reasonings and letters alone are seen to have pursued a shadow, not the thing itself. But those who have thoroughly mastered both, equipped as if with every weapon, have the sooner attained, with authority, the end they proposed. §5
For as in all matters, so most of all in architecture these two are present: that which is signified, and that which signifies. The thing signified is the proposed subject of discourse; what signifies it is the demonstration unfolded from the principles of the disciplines. Hence he who would profess himself an architect must be trained on both sides. He must also be of quick wit and receptive to learning: for neither natural talent without discipline nor discipline without natural talent can make a perfect craftsman. And he must be a man of letters, skilled with the pencil, instructed in geometry, acquainted with many histories, one who has listened diligently to philosophers, has learned music, is not ignorant of medicine, knows the responses of jurists, and has acquired knowledge of astrology and the workings of the heavens. §6
Why these things should be so, these are the reasons. The architect must know his letters, so that by written notes he may make his memory the firmer. Then he should have skill with the pencil, by which the more easily, in painted exemplars, he may design the appearance of whatever work he wills. Geometry, for its part, furnishes architecture with many aids: first it hands down the use of the straight edge and the compasses, from which, most especially, the drawing of buildings upon their plots and the directing of squares, levels, and lines are most readily carried out. Likewise, through optics, the light from fixed regions of the sky is rightly led into buildings. Through arithmetic the outlays of buildings are totaled, the calculations of measurements are worked out, and the difficult questions of symmetry are discovered by geometric principles and methods. §7
He should also have known many histories, because architects often design many ornaments in their works, and must be able, when asked, to give an account of why they have made them. For instance, if anyone has set up in place of columns in a work marble statues of women clothed in the stola, which are called Caryatides, and has placed above them mutules and cornices, he will render to those inquiring this explanation. Carya, a city of the Peloponnese, took the side of the Persian enemy against Greece. Afterward the Greeks, gloriously freed from the war by victory, by common counsel declared war on the Caryatids. And so, the town being taken, the men slain, the city desecrated, they led away the matrons into slavery, and did not suffer them to lay aside either their stolae or their matronly ornaments, so that they might not be led in one triumph and done with, but, weighed down by grave reproach as an eternal example of slavery, might be seen to pay the penalty for their city. For that reason the architects of that time designed for public buildings images of these women set in place to bear a burden, so that the penalty of the Caryatids' offense might be handed down in memory even to posterity. §8
No less did the Spartans, under the command of Pausanias son of Agesipolis, after overwhelming with a small band an infinite number of the Persian army at the battle of Plataea, and celebrating a glorious triumph of spoils and plunder, set up for posterity, as a trophy of their victory, a Persian portico made from the spoils, a token of the citizens' praise and valor; and there they placed effigies of the captives, in barbaric dress, their arrogance chastened by merited disgrace, sustaining the roof: so that their enemies might shudder, struck with terror by the effect of their courage, and their citizens, looking upon this example of valor, raised up by glory, might be ready to defend their liberty. From that time many have set up Persian statues sustaining architraves and their ornaments, and so from that subject have enriched their works with outstanding variety. There are, too, other histories of this same kind, of which architects ought to possess a knowledge. §9
Philosophy, for its part, perfects the architect in greatness of soul: to be not arrogant but rather accommodating, fair-minded, and faithful, and, above all, free of avarice. For no work can truly be done without faith and integrity. Let him not be covetous, nor have his mind occupied with the receiving of gifts, but let him preserve his dignity with gravity by keeping a good reputation: for this too philosophy prescribes. Moreover, philosophy sets forth the nature of things, which in Greek is called φυσιολογία, and which one must know the more zealously because it contains many and various natural questions, as in the conducting of waters: for by inrushes, by circulations, and by pressures under a level surface, natural breaths of air come forth in one way and another, and no one will be able to remedy their mishaps except he who has learned from philosophy the first principles of the nature of things. Likewise, whoever reads the works of Ctesibius or Archimedes and the others who have written precepts of the same kind, will not be able to understand them unless he has been instructed in these matters by the philosophers. §10
He must also have known music, so that he may have grasped the canonical and the mathematical method, and besides may be able rightly to tune ballistae, catapults, and scorpions. For in their capitals, right and left, are the apertures of the half-tones, through which twisted ropes made of sinew are drawn taut by windlasses and levers, and are not locked nor tied off until they give to the craftsman's ears a fixed and matching sound. For the arms enclosed in those tensions, when drawn back, must deliver their blow evenly and equally on both sides. And if they are not in tune, they will impede the straight discharge of missiles. §11
So too in theaters, bronze vessels, called by the Greeks ἠχεῖα, are placed in cells beneath the tiers according to a mathematical principle for the differences of sound, set up in relation to musical intervals and harmonies, divided on the circumference as the fourth, the fifth, and the double octave, so that the voice of the stage-actor, when it meets this disposition in fitting tone, arrives at the spectators' ears amplified, clearer and sweeter. So, too, no one will be able to construct hydraulic machines and the other devices similar to these organs without musical principles. §12
The science of medicine he must have known on account of the inclinations of the sky, which the Greeks call κλίματα, and of the air and of places that are salubrious or pestilent, and of the uses of waters. For without these principles no healthful dwelling can be made. He should also have knowledge of the laws that are necessary for buildings with respect to party walls, to the line of dripping eaves, to sewers, to windows, and likewise to the conducting of waters. Other matters of the same kind ought also to be known to architects, so that they may take precaution before they set up buildings, and disputes may not be left, when the works have been finished, to the heads of households; and so that, in drawing up contracts, the wise provision may safeguard both the owner and the builder: for if the contract shall have been skillfully written, it will come about that, without fraud, each is absolved from the other. From astrology, moreover, are learned east and west, south and north, and also the principle of the sky, the equinox, the solstice, and the courses of the stars. Whoever has not acquired knowledge of these, will not at all be able to understand the principle of sundials. §13
Since therefore this discipline is so adorned and abundant in learnings various and many, I do not think that any can justly profess themselves architects on the sudden, save those who, from boyhood climbing by these steps of the disciplines and nourished in the knowledge of most letters and arts, have come to the supreme temple of architecture. §14
But perhaps it will seem wondrous to the unlearned that the nature of a single man could thoroughly learn so great a number of teachings and hold them in memory. Yet when they shall have observed that all the disciplines have a connection of subjects and a communication among themselves, they will easily believe it can be done. For the encyclic discipline is made up, like a single body, from these members. And so those who from tender years are instructed in various kinds of learning recognize in all letters the same marks and the common communication of all the disciplines, and for that reason more readily grasp them all. Hence, among the architects of old, Pytheos, who built with distinction the temple of Minerva at Priene, asserts in his writings that an architect ought to be able to do more in all the arts and disciplines than those who by their own industry and practice have brought single subjects to the peak of renown. This, however, is in fact not borne out. §15
For the architect neither ought, nor can, be a grammarian of the stamp of Aristarchus, yet he must not be without letters; nor a musician such as Aristoxenus, yet not unmusical; nor a painter such as Apelles, yet not unskilled with the pencil; nor a sculptor such as Myron or Polyclitus, yet not ignorant of the principle of sculpture; nor again a physician like Hippocrates, yet no stranger to medicine; nor singularly preeminent in the other disciplines, yet in them not unskilled. For no one can attain singular elegance in such a variety of matters, since to grasp and fully master their reasonings scarcely falls within human capacity. §16
And yet not only can architects not have supreme accomplishment in all matters; even those who privately hold the mastery of particular arts do not all achieve the highest principate of praise. If then, in the single disciplines, not all artists, but only a few, have scarcely won lasting renown in the whole course of time, how can the architect, who must be skilled in many arts, not do this very thing that is wondrous and great, namely, not only to be wanting in none of them, but to surpass all those artists who, in their single disciplines, have devoted the greatest industry and perseverance? §17
In this matter, then, Pytheos seems to have erred, because he did not observe that each art is composed of two things, the work and the reasoning of it. Of these, the one is proper to those who have been practiced in particular matters, that is, the execution of the work; the other is common to all learned men, that is, the reasoning. As with physicians and musicians there is a shared discourse about the rhythm of the veins and the beat to the step; but if a wound must be healed, or a sick man snatched from danger, the musician will not step forward, but that work will belong properly to the physician. So likewise upon the instrument, not the physician but the musician will play, so that the ears may receive from the tunes their own sweetness. §18
Similarly there is a shared discussion between astrologers and musicians concerning the sympathy of the stars and of harmonies in squares and triangles, in the fourth and in the fifth, and with geometers concerning vision, which in Greek is called λόγος ὀπτικός; and with all the rest of the disciplines, many matters, indeed all, are common, but only so far as discussion is concerned. The execution of works, however, which are carried to elegance by hand and handling, belongs to those who have been instructed in a single art for the making of them. Enough and more has the man done, then, who out of each discipline has a moderate knowledge of the parts and principles of them which are necessary for architecture, so that, if it becomes necessary for him to judge or approve anything of these matters and arts, he may not be found wanting. Those, however, to whom nature has granted such dexterity, sharpness, and memory that they can have geometry, astrology, music, and the other disciplines thoroughly known, pass beyond the office of architects and become mathematicians. And so they can easily dispute against those disciplines, being armed with the more weapons of learning. Such men, however, are found but rarely, as there once were Aristarchus of Samos, Philolaus and Archytas of Tarentum, Apollonius of Perga, Eratosthenes of Cyrene, Archimedes and Scopinas of Syracuse, who left to posterity many mechanical and gnomonic inventions, discovered and set forth by number and by natural principles. §19
Since, therefore, such talents are granted by natural aptitude not at large to all peoples but only to a few men, while the office of the architect must be trained in every kind of learning, and since reason, on account of the amplitude of the subject, permits him to have, not at the pitch of necessity the highest, but moderate, knowledge of the disciplines: I ask, Caesar, of you and of those who shall read these volumes, that if anything has been set forth too little according to the rule of the grammarian's art, it be pardoned. For not as a supreme philosopher, nor as an eloquent orator, nor as a grammarian trained in the highest principles of the art, but as an architect steeped in these letters, have I striven to write these things. But as for the power of the art, and the reasonings contained within it, I promise, as I hope, that in these volumes I shall without doubt deliver them with the greatest authority, not only to those who build, but to all wise men. §20
Architecture consists of Order, which in Greek is called τάξις, and of Arrangement, which the Greeks call διάθεσις, and of Eurythmy, Symmetry, Propriety, and Distribution, which in Greek is called οἰκονομία. §21
Order is the balanced fitness of the members of a work taken separately, and, for the whole, the comparison of proportion to symmetry. It is composed of Quantity, which in Greek is called ποσότης. Quantity is the taking of modules from the members of the work itself, and, from the single parts of the members, an effect befitting the whole. Arrangement is the fitting placement of things, and the elegant effect of the work produced by those arrangements in proper quality. The species of Arrangement, which in Greek are called ἰδέαι, are these: ichnography, orthography, and scenography. Ichnography is the moderate and sustained use of the compasses and rule, from which are taken the drawings of the forms of the plots upon the ground. Orthography is the erect image of the front, moderately drawn, the figure of the work to come by due principles. Scenography, likewise, is the shading off of the front and of the receding sides, all the lines corresponding to the center of the compasses. These arise from cogitation and invention. Cogitation is care, full of study and of industry and watchfulness, for accomplishing the proposed effect with pleasure. Invention is the unfolding of obscure questions, and the reasoning of a new thing, discovered by a lively vigor. Such are the terminations of Arrangement. §22
Eurythmy is the graceful appearance, and the fitting aspect, in the compositions of the members. It is achieved when the members of a work are of heights suited to their breadths, of breadths suited to their lengths, and, in sum, when all things answer to their own symmetry. §23
Symmetry, likewise, is the fitting consensus among the very members of the work, and the answering of a set part, from the separated parts, to the appearance of the whole figure. As in the body of a man there is a symmetric quality of eurythmy, from the cubit, foot, palm, finger, and the other small parts, so it is in the completing of works. And, first, in sacred buildings the reasoning of symmetry is found either from the thicknesses of the columns, or from the triglyph, or indeed from the module; for the ballista, from the aperture, and what the Greeks call περίτρητον; for a ship, from the interscalmium, which is called διάπηγμα; and likewise, for the rest of the works, from their members. §24
Propriety is the well-measured appearance of a work composed of approved elements with authority. It is achieved by station, which in Greek is called θεματισμῷ, by custom, or by nature. By station, when buildings to Jupiter the Thunderer, to the Sky, Sun, and Moon are set up open to the air and hypaethral; for the forms of these gods, and their effects, we see present before us in the open and shining firmament. For Minerva, Mars, and Hercules temples shall be built Doric: for these gods, on account of their martial excellence, it is fitting that buildings be set up without dainty elegance. For Venus, Flora, Proserpina, Fons, and the Nymphs, temples built in the Corinthian manner will seem to have properties suited to them; for to these goddesses, because of their tenderness, works made slenderer, florid, ornamented with foliage and volutes, will seem to enhance a due propriety. But for Juno, Diana, Father Liber, and the other gods who are of the same likeness, if temples are built in the Ionic manner, a middle course will have been observed: for their institution of propriety will be tempered both from the severe manner of the Doric and from the tenderness of the Corinthian. §25
Propriety as regards custom is expressed thus: when, for interior buildings magnificent, the vestibules shall have been made likewise fitting and elegant. For if the interior parts have elegant prospects while the entrances are low and unseemly, they will not be with propriety. Likewise, if dentils be carved upon the cornices of Doric architraves, or, upon the cushioned Ionic columns, triglyphs be expressed upon the architraves, by the transferring of properties from one order into another kind of work, the aspect will be offended, since the order's usage has been otherwise instituted of old. §26
Propriety according to nature will be this: if, first, for all temples the most salubrious regions and suitable springs of water shall be chosen in those places in which the shrines are to be established; and above all for Asclepius and Salus, by whose remedies very many sick persons are seen to be cured. For when sick bodies shall have been moved from a pestilent into a salubrious place, and the use of waters shall be supplied them from healthful springs, they will recover more swiftly. So it will come about that, from the nature of the place, the divinity will receive opinions greater, heightened, and dignified. Likewise propriety by nature will be: if for bedchambers and libraries the lights are taken from the east, for baths and winter rooms from the western winter quarter, for picture-galleries and other parts which need fixed light from the north; since that region of the sky is neither brightened nor darkened by the sun's course, but has a fixed and unchanging light throughout the whole day. §27
Distribution is the fitting management of supplies and of the site, and a measured tempering, in the works, of outlay according to reason. This will be observed if, first, the architect will not seek those things which cannot be found or prepared except at great cost. For not in all places is there abundance of pit-sand, or of rubble, or of fir, or of silver-fir, or of marble; but one thing grows in one place, another in another, and their conveyance is difficult and expensive. Where there is no pit-sand, one must use river-sand or washed sea-sand; and lacks of fir or silver-fir will be remedied by using cypress, poplar, elm, pine, and the rest, which will be worked out in like manner to these. §28
Another grade of distribution will be, when buildings are variously set out according to the use of the heads of households, or to the supply of money, or to the dignity of one's eloquence. For city houses must plainly be built in one manner; those into which produce flows from country estates in another; not the same for moneylenders; otherwise for the wealthy and the luxurious; but for the powerful, by whose thoughts the commonwealth is steered, they will be laid out for public use. And in every case, the distributions of buildings are to be made fitting for all persons. §29
The parts of architecture itself are three: building, gnomonics, and machination. Building, in turn, is divided in two: one, the placement of walls and common works in public places; the other, the laying out of private buildings. Of public buildings the distributions are three: one of defense, another of religion, the third of opportunity. Of defense is the scheme of walls, towers, and gates, devised for repelling the assaults of enemies in perpetuity; of religion, the placement of shrines and sacred temples of the immortal gods; of opportunity, the disposition of common places for public use, such as harbors, fora, porticoes, baths, theaters, walks, and the other things which on the same principles are designed in public places. §30
These things should be made so that the principles of firmness, utility, and beauty are observed. The principle of firmness will be observed when the foundations have been sunk to solid ground, and in every case a careful choice, without stinting, has been made from the available supplies of material; the principle of utility, when the disposition of rooms is faultless and offers no obstruction to use, and when the distribution, for each according to its own kind, is suited and convenient to the quarters of the sky; the principle of beauty, when the look of the work shall be pleasing and graceful, and the proportion of the members shall hold the just reasonings of symmetry. §31
In the walls themselves, these shall be the first principles. First, the choice of a most salubrious site. Such a site will be high, not misty, not frosty, and looking toward regions of the sky neither sultry nor cold, but temperate; next, the nearness of marshes shall be avoided. For when morning breezes with the rising sun shall reach the town, and the mists rising at dawn shall be joined with them, and the breaths of marsh creatures, venomous, mingled with the mist, shall be scattered by their blast into the bodies of the inhabitants, they will make the place pestilent. So too, if the walls are placed along the sea and look toward the south or the west, they will not be salubrious, since in summer the southern sky at sunrise grows warm and at midday burns; and likewise that which looks westward grows mild at sunrise, hot at midday, and sweltering in the evening. §32
By these alternations of heat and cooling, the bodies which are in such places are impaired. One may observe this even in things that are not living. For in covered wine-cellars no one takes the windows from the south or from the west, but from the north, because that region at no time admits changes, but is firm forever and unchanging. For the same reason those granaries which look toward the sun's course quickly spoil their contents; and meat and fruits which are not placed in that part of the sky turned away from the sun's course are not long preserved. §33
For heat, whenever it bakes the firmness out of things and with its fiery vapors draws off by exhalation their natural qualities, dissolves them, and, softening them with its fervor, renders them weak. As we observe even in iron: though by nature hard, when thoroughly heated in furnaces by the vapor of fire it so softens that it can be easily wrought into every kind of shape; and this same, when, soft and glowing, it is cooled, plunged into cold water it hardens again and is restored to its old property. §34
One may also consider these things to be so from this: that in summer not only in pestilent but even in salubrious places all bodies become weak from the heat; and through winter those regions which are most pestilent are made salubrious, because they are consolidated by the cooling. No less, the bodies which are transferred from cold regions into hot cannot endure, but are dissolved; whereas those brought from hot places into the cold regions under the north not only do not suffer in health from the change of place, but are even strengthened. §35
Hence in placing walls care must be taken against those regions which can scatter the blasts of their heats upon the bodies of men. For as from the principles, which the Greeks call στοιχεῖα, all bodies are composed, that is, from heat and moisture, from earthy and airy, so by their mixtures, by a natural tempering, are shaped, in their kinds, the qualities of all living beings in the world. §36
Therefore, in whichever bodies the principle of heat prevails, it then kills and dissolves the rest by its fervor. Such defects a sky fervid in certain quarters produces, when it settles in open veins more than the body can bear by its natural temper of mixtures. Likewise, if moisture has seized upon the veins of bodies and made them uneven, the other principles, as if corrupted by the liquid, are diluted and their compositions dissolved of their virtues. Such faults, likewise, are infused into bodies from the coolings of moist winds and breezes. No less does the natural composition of air and earth in the body, by increasing or decreasing, weaken the other principles: the earthy, by fullness of food; the airy, by heaviness of sky. §37
But if anyone wishes to perceive these things more diligently by the senses, let him take note and observe the natures of birds, of fish, and of land animals, and so he will consider the differences of temper. For the kind of birds has one mixture; fish another; and very different from these is the nature of land creatures. Winged things have less of the earthy, less of the moist, heat in measure, and much of air. Composed, therefore, of lighter principles, they more easily rise into the onset of the air. The watery natures of fish are tempered from heat, and composed of very much air and earthy, but have exceedingly little of the moist; and the less they have of the principle of moisture in the body, the more easily they endure in moisture; and so when they are brought to land, they leave their life along with the water. Land creatures, in turn, since by the principles they are tempered from air and heat, and have less of earthy and very much of moisture, because their moist parts abound, cannot long preserve life in water. §38
If therefore these things appear as we have set them forth, and we perceive by the senses that the bodies of living things are composed from the principles, and judge that by excesses or defects of them they suffer and dissolve, we do not doubt that it must be sought with the greater diligence, when healthfulness must be sought in the placing of walls, how to choose the most temperate regions of the sky. §39
And so, again and again, I think that the ancient practice must be recalled. For our ancestors, when cattle that had pastured in the places where towns or standing camps were to be set up had been sacrificed, used to inspect the livers; and if these were at first livid and defective, they would slay others, doubting whether they had been harmed by disease or by a defect in the pasturage. When they had made trial on several and had proved, from the water and from the pasture, that the nature of the livers was whole and sound, there they placed their fortifications; but if they found them defective, they transferred the judgment likewise to human bodies, that the supply of water and food springing in those places would be pestilent to them also; and so they would migrate, and change regions, seeking healthfulness in all respects. §40
That this is so, that by pasture and food the qualities of a land may be seen to be salubrious, one may observe and learn from the fields of the Cretans which lie about the river Pothereus, which is in Crete between the two cities of Cnossos and Gortyna. For on the right and left of that river cattle graze; but of these, such as graze nearest Cnossos are disposed to enlargement of the spleen, while those on the other side, nearest Gortyna, have no perceptible spleen. Whence also physicians, inquiring about this matter, discovered in those places an herb, by the cropping of which the cattle reduced their spleens. So by gathering that herb they treat the splenetic with this medicine, which the Cretans themselves call ἄσπληνον. From this one may know that the properties of places, by their food and water, are naturally pestilent or salubrious. §41
Likewise, if walls shall have been set up by marshes, and those marshes are along the sea, and look toward the north, or between north and east, and are higher than the sea-shore, they will seem to have been set up on sound reasoning. For when ditches have been drawn, an outlet is made for the water to the shore; and the sea, swelled by storms, redounding into the marshes, stirred by the motions and mingled with the brine, does not allow the tribes of marsh creatures to be born there; and whatever come swimming from the higher places close to the shore are killed by the unaccustomed saltness. An example of this matter may be seen in the Gallic marshes about Altinum, Ravenna, and Aquileia, and the other municipalities that in such places stand nearest the marshes; because by these principles they have an incredible healthfulness. §42
But those upon which marshes settle and have no flowing outlet, whether through rivers or through ditches, as the Pomptine, standing stagnant they putrefy, and send forth in those places heavy and pestilent humors. Likewise in Apulia the old town of Salpia, which Diomedes founded on his return from Troy, or (as some have written) Elpias of Rhodes, had been placed in such a kind of site; from which the inhabitants, year by year wearied by illness, at length came to Marcus Hostilius and, petitioning him publicly, obtained that he should investigate and choose a suitable place to which to transfer the walls. He then did not delay, but at once, by learned reasonings, bought a holding along the sea in a salubrious site, and petitioned the Senate and Roman People that it be permitted to transfer the town; and he set up the walls and divided up the plots, and for a single sesterce granted them by conveyance to each townsman. With these matters accomplished, he opened a channel from a lake into the sea, and made of the lake a harbor for the township. And so now the Salpini, having gone forward four miles from the old town, dwell in a healthful place. §43
When therefore by these principles the setting out of the walls in healthfulness shall have been explained, and regions shall have been chosen rich in produce to feed the citizenry, and fortified roads, or river opportunities, or conveyances by sea through harbors shall provide ready transport of supplies to the walls, then the foundations of the towers and walls must be made thus: they are to be dug, if it can be found, down to solid ground and into the solid, as far as shall seem fit for the magnitude of the work, with a thickness greater than that of the walls which will stand above ground; and they are to be filled with as solid a structure as possible. §44
Likewise towers must be thrown forward on the outer side, so that when an enemy in his assault wishes to approach the wall, from the towers he may be wounded on the right and left by missiles, with his flanks exposed. And it seems to be most of all a matter of care that the approach to storming the wall be not easy, but that it be so carried around to precipitous places, and so devised, that the lines of the gates be not straight but oblique. For when it has been so built, then the right flank of those approaching, which is not covered by the shield, will be nearest to the wall. Towns, moreover, are to be laid out not square nor with projecting angles, but with rounded courses, so that the enemy may be observed from many places. For where angles project, defense is difficult, because the angle protects the enemy more than the defender. §45
I think the thickness of the wall is to be made such that armed men coming against one another upon it may pass by without obstruction. Then in the thickness let continuous bars of olive-wood, charred in the fire, be set in as frequently as may be, so that both faces of the wall, bound each to the other as if by fibulae by these ties, may have an everlasting firmness. For neither rot, nor storms, nor age can harm that wood; but, whether buried in earth or placed in water, it remains without defect, useful for all time. Therefore, not only in a wall, but also in substructures, and in such walls as must be made of wall-thickness, bound together by this method, they will not quickly be impaired. §46
The intervals of the towers must be so made that one be no farther from another than a bow-shot, so that, if any part be assaulted, from the towers on the right and left the enemy may be thrown back by scorpions and the other discharges of missiles. And opposite the inner parts of the towers the wall must be cut by intervals as great as the towers, so that there may be passages through the interior of the towers, timbered over and not fastened with iron. For if the enemy shall have seized any part of the wall, those resisting will cut these away; and if they act quickly, they will not suffer the enemy to penetrate the remaining parts of the towers and wall, except by casting himself down headlong. Towers, therefore, are to be made round or polygonal. §47
For square towers the siege engines break up more quickly, because the angles they shatter by striking with the ram; but in round ones they cannot harm them, since they are like driving wedges toward a center. Likewise, the fortifications of wall and towers joined to earthworks are the safest, since neither rams, nor underminings, nor the other engines avail to harm them. §48
But not in all places is the scheme of the earthwork to be used, except where outside the wall, from a high place, there shall be level-footed approach to storm the defenses. Therefore in such places, first ditches must be made with the greatest breadth and depth; next, the foundation of the wall is to be sunk inside the bed of the ditch, and to be built up with such a thickness that the earth-work above it may be easily sustained. §49
Likewise, inward from this substructure, a foundation set off from the outer one by a wide space, such that cohorts drawn up as if in line of battle may take their stand upon the breadth of the earthwork for defending it. And when these foundations have been established at such distance from one another, then let others be laid between them crosswise, joined to the outer and inner foundation, arranged like the teeth of a comb, in the manner in which the teeth of a saw are wont to be set. For when it shall have been made thus, then, the mass of the earthen load being distributed into small parts and not pressing on the whole with its weight, it will by no means be able to push out the substructures of the wall. §50
But concerning the wall itself, out of what material it shall be built or finished, for this reason nothing is to be prescribed in advance, that we cannot in all places have those supplies we desire. But where there are squared stones, or flint, or rubble-stone, or burnt brick, or sun-dried brick, these will have to be used. For just as at Babylon, because they have an abundance of liquid bitumen for lime and sand, and of burnt brick, they have a wall thus made, so not all regions or local properties can have such great advantages of a single kind that from their combinations an immaculate wall may be had for all time. §51
Once the walls are set round, there follow the divisions of plots within the wall, and the directions of streets and alleys with respect to the quarter of the sky. These will be directed rightly, if the winds be prudently excluded from the alleys. For if they are cold they injure, if hot they corrupt, if moist they harm. Wherefore this defect must be avoided, and care taken lest there happen what is wont to befall in many cities. For in the island of Lesbos the town of Mytilene is built magnificently and with elegance, but placed without prudence. In that city, when the south wind blows, men fall ill; when the northwester, they cough; when the north, they return to health, but in the alleys and streets they cannot stand because of the vehemence of the cold. §52
The wind is a flowing wave of air with an uncertain redundance of motion. It is born when heat meets moisture, and the impact of the heating forces out the power of the blowing breath. That this is true one may see from bronze aeolipiles, and thereby, from the hidden principles of the heavens, by workmanlike inventions express the truth of divinity. For aeolipiles are made of bronze, hollow. They have a very narrow mouth through which water is poured in, and are placed beside the fire; and before they grow hot they have no breath, but as soon as they begin to boil, they cast against the fire a vehement blast. So one may know and judge, from a small and most brief spectacle, concerning the great and boundless principles of the nature of the heavens and of the winds. §53
Therefore if the winds be shut out from the dwellings, they will not only make the place salubrious for sound bodies; but also, if any diseases chance to arise from other faults which in other salubrious places have cures from contrary medicine, in these, on account of the tempering produced by the exclusion of the winds, they will be cured more readily. But the diseases difficult to cure in the regions above described are these: influx, hoarseness, cough, pleurisy, consumption, spitting of blood, and the rest that are cured not by reductions but by additions. These are treated with difficulty, first because they are conceived from chills, and then because, when the strength of the sick has been worn down by the disease, the air stirred by the agitations of the winds is made thin, and at the same time draws off the juice from the afflicted bodies, and renders them the thinner. On the contrary, a gentle and dense air, which has no frequent redundances of blast, through its unmoved steadiness, adding itself to their members, nourishes and restores those who are implicated in such diseases. §54
To some it has seemed good that there are four winds: from the equinoctial east, Solanus; from the south, Auster; from the equinoctial west, Favonius; from the north, Septentrio. But those who have searched more diligently have handed down that there are eight, most notably Andronicus of Cyrrha, who even set up a model at Athens, an octagonal marble tower, and on the single sides of the octagon designated the single images of the winds, carved opposite each its own blast; above this tower he finished a marble cone, and upon that placed a bronze Triton holding forth a rod in its right hand; and so he contrived it that it should be turned by the wind, and always stand facing the blast, and hold the rod as an indicator over the image of the wind then blowing. §55
Thus the winds are disposed: between Solanus and Auster, from the winter east, Eurus; between Auster and Favonius, from the winter west, Africus; between Favonius and Septentrio, Caurus, whom more call Corus; between Septentrio and Solanus, Aquilo. In this way it seems to have been expressed so as to embrace the numbers and names and parts from which the fixed blasts of the winds blow. Since this has been so set out, to find the regions and the rising of the winds, the reckoning must be made thus. §56
Let a marble disk be set upon a level in the middle of the walls, or let the place be so polished with rule and level that the disk is not needed; and over the middle center of that place let a bronze gnomon, a finder of shadow (in Greek σκιαθήρας), be set. About the fifth hour before noon, the extreme tip of the gnomon's shadow is to be taken and marked with a point; then with the compasses, opened to the point which is the sign of the length of the gnomon's shadow, from the center a line of a circle is to be swept round. In like manner the afternoon shadow of this gnomon, as it grows, is to be observed; and when it has touched the line of the circle and made the afternoon shadow equal to the morning one, it is to be marked with a point. §57
From these two marks, with the compasses, a crossing is to be drawn; and through the crossing and the middle center a line is to be carried out to the end, that the south and the north quarters may be had. Then afterwards, a sixteenth part of the whole circle is to be taken, and the center of the compasses placed upon the southern line where it touches the circle, and marked on the right and on the left, in the southern part and in the northern, upon the circle. Then from these four marks, through the middle center, crosswise lines are to be drawn from extremity to extremity of the circle. Thus there will be had the designation of the eighth part for Auster and for Septentrio. The remaining parts, three on the right and three on the left, are to be divided equally with these throughout the whole circle, so that the eight equal divisions of the winds may be designated in the drawing. Then through the angles between each two regions of the winds the directions of the streets and alleys ought to be laid out. §58
For by these principles and by this division the troublesome force of the winds will be shut out from the dwellings and the streets. For when the streets are laid out against the direct path of the winds, from the open space of the sky the impetus and frequent blast, once shut up in the throats of the alleys, will range through with greater violence. For which reason the directions of the lanes must be turned away from the regions of the winds, so that as the winds come on they may be broken at the corners of the blocks and, thus repelled, dispersed. §59
Perhaps those who know many names of the winds will marvel that we have set forth there are only eight. But if they will consider that the circuit of the earth, by the course of the sun and the equinoctial shadows of the gnomon, and by the inclination of the heavens, was found out by Eratosthenes of Cyrene, by mathematical principles and geometrical methods, to be two hundred and fifty-two thousand stadia (which make three hundred and fifteen million paces), and that the eighth part of this, which a single wind appears to hold, is thirty-one million, nine hundred and thirty-seven thousand and five hundred paces, they ought not to marvel if in so great a space one wind, wandering by inclinations and recessions, makes varieties by a change of its blast. §60
And so, on the right and left of Auster are wont to blow Leuconotus and Altanus; of Africus, Libonotus and Subvesperus; about Favonius, Argestes, and at fixed seasons the Etesiae; at the flanks of Caurus, Circias and Corus; about Septentrio, Thracias and Gallicus; on the right and left of Aquilo, Supernas and Caecias; about Solanus, Carbas, and at a fixed season the Ornithiae; while Eurus, holding the middle places, has at its extremes Eurocircias and Volturnus. There are, moreover, many other names and blasts of winds drawn from places or from rivers or from the storms of mountains. §61
Besides these there are the morning breezes, when the sun, as he emerges from the part beneath the earth, by his turning strikes upon the moisture of the air, and by his upward thrust pours forth and expresses from the breaths the breeze of the pre-dawn. These, when they persist after the sun has risen, hold the quarter of the east wind (Eurus), and for that very reason, because it is produced from the breezes, it seems by the Greeks to be called εὖρος; and the morrow, on account of the morning breezes, is said to be named αὔριον. But there are some who deny that Eratosthenes could have reckoned the true measurement of the earth's orb. Whether that be certain or not, our writing cannot fail to possess the true boundaries of the quarters from which the breaths of the winds arise. §62
If so, then this only follows, that the single winds have not a fixed ratio of measure, but have either greater or lesser blasts. Since these things have been set forth by us briefly, that they may be more easily understood, it has seemed good to me, at the end of the volume, to set out two figures (or σχήματα, as the Greeks call them): one so laid out that it may appear whence the fixed breaths of the winds arise; the other, in what manner the harmful blasts may be avoided by directing the lanes and streets away from their impetus. There will be, upon a leveled plane, a center where the letter A is, and the morning shadow of the gnomon where B is; and from the center at A, drawing the compasses open to that mark of the shadow at B, let a line of a circle be swept round. The gnomon being set back where it had been before, one must wait until the shadow decreases and then, by growing again, makes the afternoon shadow equal to the morning one, and touches the line of the circle where the letter C shall be. Then from the mark where B is, and from the mark where C is, with the compasses let a crossing be described, where will be D; thereafter through the crossing at D and the center let a line be drawn out to the farthest point, upon which line will be the letters E and F. This line will be the index of the southern and northern quarters. §63
Then with the compasses a sixteenth part of the whole circle is to be taken, and the center of the compasses is to be placed on the southern line where it touches the circle, where the letter E is, and marks made on the right and on the left, where the letters G and H shall be. Likewise, in the northern part, the center of the compasses is to be placed on the circle, on the northern line where the letter F is, and marks made on the right and on the left, where the letters I and K are; and from G to K, and from H to I, through the center, lines are to be carried. Thus the space from G to H will be the space of the wind Auster and of the southern part; likewise the space from I to K will be that of Septentrio. The remaining parts, three on the right and three on the left, are to be divided equally, those toward the east on which are the letters L and M, and those toward the west on which are the letters N and O. From M to O and from L to N, lines are to be drawn crosswise. And so the spaces of the eight winds will be equal in the circuit. When they are so drawn, in the single angles of the octagon, beginning from the south, between Eurus and Auster will be the letter G; between Auster and Africus, H; between Africus and Favonius, N; between Favonius and Caurus, O; between Caurus and Septentrio, K; between Septentrio and Aquilo, I; between Aquilo and Solanus, L; between Solanus and Eurus, M. Thus, these things being accomplished, between the angles of the octagon let the gnomon be set, and so let the divisions of the alleys be directed. §64
With the alleys divided and the streets established, the choosing of plots for the convenience and common use of the city is to be set forth, for sacred temples, for the forum, and for the other common places. And if the walls shall be by the sea, the plot where the forum is established must be chosen nearest to the harbor; but if inland, in the middle of the town. For sacred temples, those of the gods under whose especial tutelage the city appears to be (as Jupiter, Juno, and Minerva), plots are to be assigned in the loftiest place, from which the greatest part of the walls may be descried. For Mercury, however, in the forum; or, as for Isis and Serapis, in the emporium. For Apollo and for Father Liber, next to the theater. For Hercules, in those cities in which there are no gymnasia or amphitheaters, next to the circus. For Mars, outside the city but next to the training-field; and, likewise, for Venus, near the harbor. It has been so dedicated in the writings of the Etruscan haruspical discipline also: that outside the wall the shrines of Venus, Vulcan, and Mars be placed, so that amorous desire may not become habitual in the city among youths and matrons of households, and that, the power of Vulcan being summoned out from the walls by religious rites and sacrifices, the buildings may be seen to be freed from the fear of fires; and that, Mars's divinity being dedicated outside the walls, there may be no armed dissension among citizens, but, defended by him from enemies, they may be preserved from the danger of war. §65
Likewise for Ceres, in a place outside the city, to which all men need not always go except by the necessity of sacrifice, since that place ought to be guarded with religious, chaste, and holy morals. And for the other gods, plots are to be distributed for temples suited to the scheme of their sacrifices. But concerning the building itself of sacred temples and their symmetries, I will render the reasonings in the third and fourth books; for in the second it has seemed good to me first to set forth the supplies of materials which must be prepared for buildings, what their virtues are, and what use they have; thereafter, to go through the dimensions of buildings, and their orders, and the several kinds of symmetries, and to treat them in the several volumes. §66