Vitruvius Quotes

...when exposed to moisture... it cannot take in liquid on account of its compactness, but, withdrawing from the moisture, it resists it and warps, thus making cracks.
Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 8

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book III, Chapter III, Sec. 13
Context: For the eye is always in search of beauty, and if we do not gratify its desire for pleasure by a proportionate enlargement in these measures, and thus make compensation for ocular deception, a clumsy and awkward appearance will be presented to the beholder.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 17

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book V, Chapter I, Sec. 4

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book V, Chapter V, Sec. 6

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VI, Sec. 2-3

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VI "Pozzolana" Sec. 1

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter II, Sec. 2

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter IV, Sec. 3

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter II, Sec. 7

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 7
Context: Our workmen, in their hurry to finish, devote themselves only to the facings of the walls, setting them upright but filling the space between with a lot of broken stones and mortar thrown in anyhow. This makes three different sections in the same structure; two consisting of facing and one of filling between them. The Greeks, however, do not build so; but laying their stones level and building every other stone lengthwise into the thickness, they do not fill the space between, but construct the thickness of their walls in one solid and unbroken mass from the facings to the interior. Further, at intervals they lay single stones which run through the entire thickness of the wall. These stones... by their bonding powers... add very greatly to the solidity of the walls.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 7
Context: Our workmen, in their hurry to finish, devote themselves only to the facings of the walls, setting them upright but filling the space between with a lot of broken stones and mortar thrown in anyhow. This makes three different sections in the same structure; two consisting of facing and one of filling between them. The Greeks, however, do not build so; but laying their stones level and building every other stone lengthwise into the thickness, they do not fill the space between, but construct the thickness of their walls in one solid and unbroken mass from the facings to the interior. Further, at intervals they lay single stones which run through the entire thickness of the wall. These stones... by their bonding powers... add very greatly to the solidity of the walls.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VI, Sec. 5
Context: There will still be the question why Tuscany, although it abounds in hot springs, does not furnish a powder out of which, on the same principle, a wall can be made which will set fast under water.... The properties of the soil are as different and unlike as are the various countries.... Hence it is not in all the places where boiling springs of hot water abound that there is the same combination of favourable circumstances... For things are produced in accordance with the will of nature; not to suit man's pleasure, but as it were by a chance distribution.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter I, Sec. 9
Context: There is no kind of material, no body, and no thing that can be produced or conceived of, which is not made up of elementary particles; and nature does not admit of a truthful exploration in accordance with the doctrines of the physicists without an accurate demonstration of the primary causes of things, showing how and why they are as they are.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter II, Sec. 8
Context: Economy denotes the the proper management of materials and of site, as well as a thrifty balancing of cost and common sense in the construction of works.... the architect does not demand things which cannot be found or made ready without great expense. For example: it is not everywhere that there is plenty of pitsand, rubble, fir, clear fir, and marble... Where there is no pitsand, we must use the kinds washed up by rivers or by the sea... and other problems we must solve in similar ways.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 14
Context: The larch... is not only preserved from decay and the worm by the great bitterness of its sap, but also it cannot be kindled with fire nor ignite of itself, unless like stone in a limekiln it is burned with other wood.... This is because there is a very small proportion of the elements of fire and air in its composition, which is a dense and solid mass of moisture and the earthy, so that it has no open pores through which fire can find its way... Further, its weight will not let it float in water.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VII, Sec. 1
Context: The stone in quarries is found to be of different and unlike qualities. In some it is soft... in others it is medium... in still others it is hard as in lava quarries. There are also numerous other kinds: for instance, in Campania, red and black tufas; in Umbria, Picenum, and Venetia, white tufa which can be cut with a toothed saw like wood.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter V, Sec. 3
Context: The thickness of the wall should, in my opinion, be such that armed men meeting on top of it may pass one another without interference. In the thickness there should be set a very close succession of ties made of charred olive wood, binding the two faces of the wall together like pins, to give it lasting endurance. For that is a material which neither decay, nor the weather, nor time can harm, but even though buried in the earth or set in the water it keeps sound and useful forever. And so not only city walls but substructures in general and all walls that require a thickness like that of a city wall, will be long in falling to decay if tied in this manner.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter IV, Sec. 2
Context: Nobody draws the light for covered wine rooms from the south or west, but rather from the north, since that quarter is never subject to change but is always constant and unshifting. So it is with granaries: grain exposed to the sun's course soon loses its good quality, and provisions and fruit, unless stored in a place unexposed to the sun's course, do not keep long.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter V "The City Walls" Sec. 1
Context: After insuring on these principles the healthfulness of the future city... the next thing to do is to lay the foundations for the towers and walls. Dig down to solid bottom, if it can be found, and lay them therein, going as deep as the magnitude of the proposed work seems to require. They should be much thicker than the part of the walls that will appear above ground and their structure should be as solid as it can possibly be laid.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VII, Sec. 2
Context: Travertine and all stone of that class can stand injury whether from a heavy load laid upon it or from the weather; exposure to fire, however, it cannot bear, but splits and cracks to pieces at once. This is because in its natural composition there is but little moisture and not much of the earthy, but a great deal of air and of fire. Therefore, it is not only without the earthy and watery elements, but when fire, expelling the air from it by the operation and force of heat, penetrates into its inmost parts and occupies the empty spaces of the fissures there comes a great glow and the stone is made to burn as fiercely as do the particles of fire itself.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter VI, Sec. 4
Context: Some have held that there are only four winds: Solanus from the east; Auster from the south; Favonius from due west; Septentrio from the north. But more careful investigators tell us that there are eight.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 2
Context: Both kinds should be constructed of the smallest stones, so that the walls, being thoroughly puddled with the mortar, which is made of lime and sand, may hold together longer. If the stones used are soft and porous, they are apt to suck the moisture out of the mortar and so to dry it up. But when there is abundance of lime and sand, the wall, containing more moisture, will not soon lose its strength, for they will hold it together. But if the moisture is sucked out of the mortar by the porous rubble, and the lime and sand separate and disunite, the rubble can no longer adhere to them and the wall will in time become a ruin.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VII, Sec. 5
Context: Since, on account of the proximity of the stone-quarries... nearest to the city, necessity drives us to make use of their products, we must proceed as follows if we wish our work to be finished without flaws. Let the stone be taken from the quarry two years before building is to begin, and not in winter, but in summer. Then let it lie exposed in an open place. Such stone as been damaged by the two years of exposure should be used in the foundations. The rest, which remains unhurt, has passed the test of nature and will endure in those parts of the building which are above ground. This precaution should be observed, not only with dimension stone, but also with the rubble which is to be used in walls.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter VI, Sec. 7-8
Context: Let the directions of your streets and alleys be laid down on the lines of division between the quarters of two winds. On this principle of arrangement the disagreeable force of the winds will be shut out from dwellings and lines of houses. For if the streets run full in the face of the winds, their constant blasts rushing in from the open country, and then confined by narrow alleys, will sweep through them with great violence. The lines of houses must therefore be directed away from the quarters from which the winds blow, so that as they come in they may strike against the angles of the blocks and their force thus be broken and dispersed.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 10
Context: At Halicarnassus, the house of that most potent king Mausolus, though decorated throughout with Proconnesian marble, has walls built of brick which are to this day of extraordinary strength, and are covered with stucco so highly polished that they seem to be as glistening as glass. That king did not use brick from poverty; for he was choke-full of revenues, being ruler of all Caria.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter VII, Sec. 1
Context: For the temples, the sites for those of the gods under whose particular protection the state is thought to rest and for Jupiter, Juno, and Minerva, should be on the very highest point commanding a view of the greater part of the city. Mercury should be in the forum, or, like Isis and Serapis, in the emporium; Apollo and Father Bacchus near the theater; Hercules at the circus in communities which have no gymnasia nor amphitheatres; Mars outside the city but at the training ground, and so Venus, but at the harbor. It is moreover shown by the Etruscan diviners in treatises on their science that the fanes of Venus, Vulcan, and Mars should be situated outside the walls, in order that the young men and married women may not become habituated in the city to the temptations incident to the worship of Venus, and that buildings may be free from the terror of fires through the religious rites and sacrifices which call the power of Vulcan beyond the walls. As for Mars, when that divinity is enshrined outside the walls, the citizens will never take up arms against each other, and he will defend the city from its enemies and save it from danger in war.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter I, Sec. 16
Context: As for men upon whom nature has bestowed so much ingenuity, acuteness, and memory that they are able to have a thorough knowledge of geometry, astronomy, music, and the other arts, they go beyond the functions of architects and become pure mathematicians. Hence they can readily take up positions against those arts because many are the artistic weapons with which they are armed. Such men, however, are rarely found, but there have been such at times; for example, Aristarchus of Samos, Philolaus, and Archytas of Tarentum, Apollonius of Perga, Eratosthenes of Cyrene, and among Syracusans Archimedes and Scopinas, who through mathematics and natural philosophy discovered, expounded, and left to posterity many things in connection with mechanics and with sundials.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 12
Context: The hornbeam... is not a wood that breaks easily and is very convenient to handle. Hence the Greeks call it "zygia," because they make of it yokes for their draught animals... Cypress and pine are also just as admirable; for although they... are apt to warp when used in buildings... they can be kept to a great age without rotting because the liquid contained within their substances has a bitter taste which by its pungency prevents the entrance of decay or of those little creatures which are destructive. Hence buildings made of these kinds of wood last for an unending period of time.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IV, Sec. 2
Context: If there are no sandpits from which it can be dug, then we must sift it out from river beds or from gravel or even from the sea beach. This kind however has these defects when used in masonry: it dries slowly... and such a wall cannot carry vaultings. Furthermore, when sea-sand is used in walls and these are coated with stucco, a salty efflorescence is given out which spoils the surface.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book VIII, Chapter VI, Sec. 13
Context: To guard against this, we must proceed as follows. Let down a lighted lamp, and if it keeps burning, a man may make the descent without danger.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter V "Lime" Sec. 1
Context: With regard to lime we must be careful that it is burned from a stone which, whether soft or hard, is in any case white. Lime made of close-grained stone of the harder sort will be good in structural parts; lime of porous stone, in stucco. After slaking it, mix your mortar, if using pitsand, in the proportions of three parts of sand to one of lime; if using river or sea-sand, mix two parts of sand with one of lime. These will be the right proportions for the composition of the mixture. Further, in using river or sea-sand, the addition of a third part composed of burnt brick, pounded up and sifted, will make your mortar of a better composition to use.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter VII, Sec. 1
Context: For the temples, the sites for those of the gods under whose particular protection the state is thought to rest and for Jupiter, Juno, and Minerva, should be on the very highest point commanding a view of the greater part of the city. Mercury should be in the forum, or, like Isis and Serapis, in the emporium; Apollo and Father Bacchus near the theater; Hercules at the circus in communities which have no gymnasia nor amphitheatres; Mars outside the city but at the training ground, and so Venus, but at the harbor. It is moreover shown by the Etruscan diviners in treatises on their science that the fanes of Venus, Vulcan, and Mars should be situated outside the walls, in order that the young men and married women may not become habituated in the city to the temptations incident to the worship of Venus, and that buildings may be free from the terror of fires through the religious rites and sacrifices which call the power of Vulcan beyond the walls. As for Mars, when that divinity is enshrined outside the walls, the citizens will never take up arms against each other, and he will defend the city from its enemies and save it from danger in war.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter III, Sec. 2
Context: All... must be built with due reference to durability, convenience, and beauty. Durability will be assured when foundations are carried down to the solid ground and materials wisely and liberally selected; convenience, when the arrangement of the apartments is faultless and presents no hindrance to use, and when each class of building is assigned to its suitable and appropriate exposure; and beauty, when the appearance of the work is pleasing and in good taste, and when its members are in due proportion according to correct principles of symmetry.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter II, Sec. 2

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter VI, Sec. 4

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX "Timber" Sec. 1
Context: In Spring all trees become pregnant, and they are all employing their natural vigor in the production of leaves and of the fruits that return every year. The requirements of that season render them empty and swollen, and so they are weak and feeble because of their looseness of texture. This is also the case with women who have conceived. Their bodies are not considered perfectly healthy until the child is born.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VII, Sec. 3-4
Context: There are also several quarries called Anician in the territory of Tarquinii, the stone being of the color of peperino.... Neither the season of frost nor exposure to fire can harm it, but it remains solid and lasts to a great age, because there is only a little air and fire in its natural composition, a moderate amount of moisture, and a great deal of the earthy. Hence its structure is of close texture and solid, and so it cannot be injured by the weather or by the force of fire. Monuments in the neighborhood of the town of Ferento which are made of stone from these quarries... gracefully carved. Old as these are, they look as fresh as if they were only just finished. Bronze workers, also, make molds for the casting of bronze out of stone from these quarries and find it very useful in bronze-founding.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter III "Brick" Sec. 1
Context: Bricks... should not be made of sandy or pebbly clay, or of fine gravel, because when made of these kinds they are in the first place heavy; and secondly when washed by the rain as they stand in walls, they go to pieces and break up, and the straw in them does not hold together on account of the roughness of the material. They should rather be made of white and chalky or of red clay, or even of a coarse grained gravelly clay. These materials are smooth and therefore durable; they are not heavy to work with, and are readily laid.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX "Timber" Sec. 1
Context: In Spring all trees become pregnant, and they are all employing their natural vigor in the production of leaves and of the fruits that return every year. The requirements of that season render them empty and swollen, and so they are weak and feeble because of their looseness of texture. This is also the case with women who have conceived. Their bodies are not considered perfectly healthy until the child is born.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 14
Context: The larch... is not only preserved from decay and the worm by the great bitterness of its sap, but also it cannot be kindled with fire nor ignite of itself, unless like stone in a limekiln it is burned with other wood.... This is because there is a very small proportion of the elements of fire and air in its composition, which is a dense and solid mass of moisture and the earthy, so that it has no open pores through which fire can find its way... Further, its weight will not let it float in water.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter I, Sec. 9
Context: In theatres... there are the bronze vessels in which are placed in niches under the seats in accordance with the musical intervals on mathematical principles. These vessels are arranged with a view to musical concords or harmony, and apportioned in the compass of the fourth, the fifth, and the octave, and so on up to the double octave, in such a way that when the voice of an actor falls in unison with any of them its power is increased, and it reaches the ears of the audience with greater clearness and sweetness. Water organs too, and the other instruments which resemble them cannot be made by one who is without the principles of music.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 12
Context: The hornbeam... is not a wood that breaks easily and is very convenient to handle. Hence the Greeks call it "zygia," because they make of it yokes for their draught animals... Cypress and pine are also just as admirable; for although they... are apt to warp when used in buildings... they can be kept to a great age without rotting because the liquid contained within their substances has a bitter taste which by its pungency prevents the entrance of decay or of those little creatures which are destructive. Hence buildings made of these kinds of wood last for an unending period of time.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IV "Sand" Sec. 1
Context: In walls of masonry the first question must be with regard to the sand, in order that it may be fit to mix into mortar and have no dirt in it. The kinds of pitsand are these: black, gray, red, and carbuncular. Of these the best will be found to be that which crackles when rubbed in the hand, while that which has much dirt in it will not be sharp enough. Again: throw some sand upon a white garment and then shake it out; if the garment is not soiled and no dirt adheres to it, the sand is suitable.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter IV, Sec. 9
Context: Our ancestors, when about to build a town or an army post, sacrificed some of the cattle that were wont to feed on the site proposed and examined their livers. If the livers of the first victims were dark-coloured or abnormal, they sacrificed others, to see whether the fault was due to disease or their food. They never began to build defensive works in a place until after they had made many such trials and satisfied themselves that good water and food had made the liver sound and firm.... healthfulness being their chief object.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter V "Lime" Sec. 1
Context: With regard to lime we must be careful that it is burned from a stone which, whether soft or hard, is in any case white. Lime made of close-grained stone of the harder sort will be good in structural parts; lime of porous stone, in stucco. After slaking it, mix your mortar, if using pitsand, in the proportions of three parts of sand to one of lime; if using river or sea-sand, mix two parts of sand with one of lime. These will be the right proportions for the composition of the mixture. Further, in using river or sea-sand, the addition of a third part composed of burnt brick, pounded up and sifted, will make your mortar of a better composition to use.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 17
Context: With the present importance of the city [of Rome] and the unlimited numbers of its population, it is necessary to increase the number of dwelling-places indefinitely. Consequently, as the ground floors could not admit of so great a number living in the city, the nature of the case has made it necessary to find relief by making the buildings high. In these tall piles reared with piers of stone, walls of burnt brick, and partitions of rubble work, and provided with floor after floor, the upper stories can be partitioned off into rooms to very great advantage. The accommodations within the city walls being thus multiplied as a result of the many floors high in the air, the Roman people easily find excellent places in which to live.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter V, Sec. 8
Context: Dimension stone, flint, rubble, burnt or unburnt brick,—use them as you find them. For it is not every neighborhood or particular locality that can have a wall built of burnt brick like that at Babylon, where there was plenty of asphalt to take the place of lime and sand, and yet possibly each may be provided with materials of equal usefulness so that out of them a faultless wall may be built to last forever.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 10
Context: In swampy places, alder piles driven close together beneath the foundations of buildings take in the water which their own consistence lacks and remain imperishable forever, supporting structures of enormous weight and keeping them from decay. Thus a material which cannot last even a little while above ground, endures for a long time when covered with moisture.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter V, Sec. 7
Context: Lay a second foundation enough inside the first... Having laid these two foundations... build cross walls between them uniting the outer and inner foundation in a comb like arrangement set like teeth of a saw. With this form of construction the burden of earth will be distributed into small bodies and will not lie with all its weight in one crushing mass so as to thrust out substructures.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter III, Sec. 2
Context: Bricks will be most serviceable if made two years before using; for they cannot dry thoroughly in less time. When fresh undried bricks are used in a wall, the stucco covering stiffens and hardens into a permanent mass, but the bricks settle and... the motion caused by their shrinking prevents them from adhering to it, and they are separated from their union with it.... at Utica in constructing walls they use brick only if it is dry and made five years previously, and approved as such by the authority of a magistrate.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter X "Highland and Lowland Fir" Sec. 1
Context: Trees which grow in places facing the course of the sun are not of porous fiber but are solid, being drained by the dryness... The trees in sunny neighborhoods, therefore, being solidified by the compact texture of their fiber, and not being porous from moisture, are very useful, so far as durability goes, when they are hewn into timber. The lowland firs, being conveyed from sunny places, are better than those highland firs, which are brought here from shady places.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 20
Context: As for "wattle and daub" I could wish that it had never been invented. The more it saves in time and gains in space, the greater and the more general is the disaster that it may cause; for it is made to catch fire, like torches. It seems better, therefore, to spend on walls of burnt brick, and be at expense, than to save with "wattle and daub," and be in danger. And, in the stucco covering, too, it makes cracks from the inside by the arrangement of its studs and girts. For these swell with moisture as they are daubed, and then contract as they dry, and by their shrinking cause the solid stucco to split. But since some are obliged to use it either to save time or money, or for partitions on an unsupported span, the proper method of construction is as follows. Give it a high foundation so that it may nowhere come in contact with the broken stone-work composing the floor...

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter VIII, Sec. 9
Context: In Sparta, paintings have been taken out of certain walls by cutting through the bricks, then have been placed in wooden frames, and so brought to the Comitium to adorn the aedileship of [C. Visellius] Varro and [C. Licinius] Murena.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 10
Context: In swampy places, alder piles driven close together beneath the foundations of buildings take in the water which their own consistence lacks and remain imperishable forever, supporting structures of enormous weight and keeping them from decay. Thus a material which cannot last even a little while above ground, endures for a long time when covered with moisture.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter II, Sec. 5
Context: The construction of temples of the Ionic order to Juno, Diana, Father Bacchus, and the other gods of that kind, will be in keeping with the middle position which they hold; for the building of such will be an appropriate combination of the severity of the Doric and the delicacy of the Corinthian.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 3
Context: In felling a tree we should cut into the trunk of it to the very heart, and then leave it standing so that the sap may drain out drop by drop throughout the whole of it.... Then and not till then, the tree being drained dry and the sap no longer dripping, let it be felled and it will be in the highest state of usefulness.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 12
Context: The hornbeam... is not a wood that breaks easily and is very convenient to handle. Hence the Greeks call it "zygia," because they make of it yokes for their draught animals... Cypress and pine are also just as admirable; for although they... are apt to warp when used in buildings... they can be kept to a great age without rotting because the liquid contained within their substances has a bitter taste which by its pungency prevents the entrance of decay or of those little creatures which are destructive. Hence buildings made of these kinds of wood last for an unending period of time.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter V, Sec. 5
Context: The towers themselves must be either round or polygonal. Square towers are sooner shattered by military engines, for the battering rams pound their angles to pieces but in the case of round towers they can do no harm being engaged as it were in driving wedges to their center.

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book II, Chapter IX, Sec. 9

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter II, Sec. 5