"The Constitutions of the Free-Masons" (1734)

James Anderson's "The Constitutions of the Free-Masons" (1734), reprinted by Benjamin Franklin, describes Vitruvius as "the Father of all true Architects to this Day."[26]


Vitruvius - Wikipedia

Vitruvius (/vɪˈtruːviəs/; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work titled De architectura.[1] As the only treatise on architecture to survive from antiquity, it has been regarded since the Renaissance as the first book on architectural theory, as well as a major source on the canon of classical architecture.[2] It is not clear to what extent his contemporaries regarded his book as original or important.

He states that all buildings should have three attributes: firmitas, utilitas, and venustas ("strength", "utility", and "beauty"),[3] principles reflected in much Ancient Roman architecture. His discussion of perfect proportion in architecture and the human body led to the famous Renaissance drawing of the Vitruvian Man by Leonardo da Vinci.

Little is known about Vitruvius' life, but by his own description[4] he served as an artilleryman, the third class of arms in the Roman military offices. He probably served as a senior officer of artillery in charge of doctores ballistarum (artillery experts) and libratores who actually operated the machines.[5] As an army engineer he specialized in the construction of ballista and scorpio artillery war machines for sieges. It is possible that Vitruvius served with Julius Caesar's chief engineer Lucius Cornelius Balbus.

Vitruvius' De architectura was widely copied in the Middle Ages and survives in many dozens of manuscripts[6] though in 1414 it was "rediscovered" by the Florentine humanist Poggio Bracciolini in the library of Saint Gall Abbey. Leon Battista Alberti published it in his seminal treatise on architecture, De re aedificatoria (c. 1450). The first known Latin printed edition was by Fra Giovanni Sulpitius in Rome in 1486. Translations followed in Italian, French, English, German, Spanish, and several other languages. Though any original illustrations have been lost, the first illustrated edition was published in Venice in 1511 by Fra Giovanni Giocondo, with woodcut illustrations based on descriptions in the text. Bramante, Michelangelo, Palladio, Vignola and earlier architects are known to have studied the work of Vitruvius, and consequently it has had a significant impact on the architecture of many European countries.[1]

Life and career
Little is known about Vitruvius' life. Most inferences about him are extracted from his only surviving work De Architectura. His full name is sometimes given as "Marcus Vitruvius Pollio", but both the first and last names are uncertain.[7] Marcus Cetius Faventinus writes of "Vitruvius Polio aliique auctores"; this can be read as "Vitruvius Polio, and others" or, less likely, as "Vitruvius, Polio, and others". An inscription in Verona, which names a Lucius Vitruvius Cordo, and an inscription from Thilbilis in North Africa, which names a Marcus Vitruvius Mamurra have been suggested as evidence that Vitruvius and Mamurra (who was a military praefectus fabrum under Julius Caesar) were from the same family;[8] or were even the same individual. Neither association, however, is borne out by De Architectura (which Vitruvius dedicated to Augustus), nor by the little that is known of Mamurra.

Vitruvius was a military engineer (praefectus fabrum), or a praefect architectus armamentarius of the apparitor status group (a branch of the Roman civil service). He is mentioned in Pliny the Elder's table of contents for Naturalis Historia (Natural History), in the heading for mosaic techniques.[9] Frontinus refers to "Vitruvius the architect" in his late 1st-century work De aquaeductu.

Likely born a free Roman citizen, by his own account Vitruvius served in the Roman army under Caesar with the otherwise poorly identified Marcus Aurelius, Publius Minidius and Gnaeus Cornelius. These names vary depending on the edition of De architectura. Publius Minidius is also written as Publius Numidicus and Publius Numidius, speculated as the same Publius Numisius inscribed on the Roman Theatre at Heraclea.[10]

As an army engineer he specialized in the construction of ballista and scorpio artillery war machines for sieges. It is speculated that Vitruvius served with Caesar's chief engineer Lucius Cornelius Balbus.[11]

The locations where he served can be reconstructed from, for example, descriptions of the building methods of various "foreign tribes". Although he describes places throughout De Architectura, he does not say he was present. His service likely included north Africa, Hispania, Gaul (including Aquitaine) and Pontus.

To place the role of Vitruvius the military engineer in context, a description of "The Prefect of the camp" or army engineer is quoted here as given by Flavius Vegetius Renatus in The Military Institutions of the Romans:

The Prefect of the camp, though inferior in rank to the [Prefect], had a post of no small importance. The position of the camp, the direction of the entrenchments, the inspection of the tents or huts of the soldiers and the baggage were comprehended in his province. His authority extended over the sick, and the physicians who had the care of them; and he regulated the expenses relative thereto. He had the charge of providing carriages, bathhouses and the proper tools for sawing and cutting wood, digging trenches, raising parapets, sinking wells and bringing water into the camp. He likewise had the care of furnishing the troops with wood and straw, as well as the rams, onagri, balistae and all the other engines of war under his direction. This post was always conferred on an officer of great skill, experience and long service, and who consequently was capable of instructing others in those branches of the profession in which he had distinguished himself.[12]

At various locations described by Vitruvius,[13] battles and sieges occurred. He is the only source for the siege of Larignum in 56 BC.[14] Of the battlegrounds of the Gallic War there are references to:

The siege and massacre of the 40,000 residents at Avaricum in 52 BC. Vercingetorix commented that "the Romans did not conquer by valour nor in the field, but by a kind of art and skill in assault, with which they [Gauls] themselves were unacquainted."[15]
The broken siege at Gergovia in 52 BC.
The circumvallation and Battle of Alesia in 52 BC. The women and children of the encircled city were evicted to conserve food, and then starved to death between the opposing walls of the defenders and besiegers.
The siege of Uxellodunum in 51 BC.
These are all sieges of large Gallic oppida. Of the sites involved in Caesar's civil war, we find the Siege of Massilia in 49 BC (modern France),[16] the Battle of Dyrrhachium of 48 BC (modern Albania), the Battle of Pharsalus in 48 BC (Hellas – Greece), the Battle of Zela of 47 BC (modern Turkey), and the Battle of Thapsus in 46 BC in Caesar's African campaign.[17] A legion that fits the same sequence of locations is the Legio VI Ferrata, of which ballista would be an auxiliary unit.

Mainly known for his writings, Vitruvius was himself an architect. In Roman times architecture was a broader subject than at present including the modern fields of architecture, construction management, construction engineering, chemical engineering, civil engineering, materials engineering, mechanical engineering, military engineering and urban planning;[18] architectural engineers consider him the first of their discipline, a specialization previously known as technical architecture.

In his work describing the construction of military installations, he also commented on the miasma theory – the idea that unhealthy air from wetlands was the cause of illness, saying:

For fortified towns the following general principles are to be observed. First comes the choice of a very healthy site. Such a site will be high, neither misty nor frosty, and in a climate neither hot nor cold, but temperate; further, without marshes in the neighbourhood. For when the morning breezes blow toward the town at sunrise, if they bring with them mists from marshes and, mingled with the mist, the poisonous breath of the creatures of the marshes to be wafted into the bodies of the inhabitants, they will make the site unhealthy. Again, if the town is on the coast with southern or western exposure, it will not be healthy, because in summer the southern sky grows hot at sunrise and is fiery at noon, while a western exposure grows warm after sunrise, is hot at noon, and at evening all aglow.[19]

Frontinus mentions Vitruvius in connection with the standard sizes of pipes:[20] probably the role for which he was most widely respected in Roman times. He is often credited as father of architectural acoustics for describing the technique of echeas placement in theaters.[21] The only building, however, that we know Vitruvius to have worked on is one he tells us about,[22] a basilica completed in 19 BC.[23] It was built at Fanum Fortunae, now the modern town of Fano. The Basilica di Fano (to give the building its Italian name) has disappeared so completely that its very site is a matter of conjecture, although various attempts have been made to visualise it.[24] The early Christian practice of converting Roman basilicae (public buildings) into cathedrals implies the basilica may be incorporated into the Romanesque Fano Cathedral.

In later years the emperor Augustus, through his sister Octavia Minor, sponsored Vitruvius, entitling him with what may have been a pension to guarantee financial independence.[4]

Whether De architectura was written by one author or is a compilation completed by subsequent librarians and copyists, remains an open question. The date of his death is unknown, which suggests that he had enjoyed only a little popularity during his lifetime.[citation needed]

Gerolamo Cardano, in his 1552 book De subtilitate rerum, ranks Vitruvius as one of the 12 persons whom he supposes to have excelled all men in the force of genius and invention; and might have given him first place if it was clear that he had set down his own discoveries.[25]

James Anderson's "The Constitutions of the Free-Masons" (1734), reprinted by Benjamin Franklin, describes Vitruvius as "the Father of all true Architects to this Day."[26]



















Siege - Wikipedia
A siege is a military blockade of a city, or fortress, with the intent of conquering by attrition, or by well-prepared assault. This derives from Latin: sedere, lit. 'to sit'.[1] Siege warfare (also called siegecraft or poliorcetics) is a form of constant, low-intensity conflict characterized by one party holding a strong, static, defensive position. Consequently, an opportunity for negotiation between combatants is common, as proximity and fluctuating advantage can encourage diplomacy.

A siege occurs when an attacker encounters a city or fortress that cannot be easily taken by a quick assault, and which refuses to surrender. Sieges involve surrounding the target to block provision of supplies and reinforcement or escape of troops (a tactic known as "investment"[2]). This is typically coupled with attempts to reduce the fortifications by means of siege engines, artillery bombardment, mining (also known as sapping), or the use of deception or treachery to bypass defenses.

Failing a military outcome, sieges can often be decided by starvation, thirst, or disease, which can afflict either the attacker or defender. This form of siege, though, can take many months or even years, depending upon the size of the stores of food the fortified position holds. The attacking force can circumvallate the besieged place, which is to build a line of earth-works, consisting of a rampart and trench, surrounding it. During the process of circumvallation, the attacking force can be set upon by another force, an ally of the besieged place, due to the lengthy amount of time required to force it to capitulate. A defensive ring of forts outside the ring of circumvallated forts, called contravallation, is also sometimes used to defend the attackers from outside.


Picture of the siege of Rancagua during the Chilean War of Independence
Ancient cities in the Middle East show archaeological evidence of fortified city walls. During the Warring States period of ancient China, there is both textual and archaeological evidence of prolonged sieges and siege machinery used against the defenders of city walls. Siege machinery was also a tradition of the ancient Greco-Roman world. During the Renaissance and the early modern period, siege warfare dominated the conduct of war in Europe. Leonardo da Vinci gained some of his renown from design of fortifications. Medieval campaigns were generally designed around a succession of sieges. In the Napoleonic era, increasing use of ever more powerful cannons reduced the value of fortifications. In the 20th century, the significance of the classical siege declined. With the advent of mobile warfare, a single fortified stronghold is no longer as decisive as it once was. While traditional sieges do still occur, they are not as common as they once were due to changes in modes of battle, principally the ease by which huge volumes of destructive power can be directed onto a static target. Modern sieges are more commonly the result of smaller hostage, militant, or extreme resisting arrest situations.




Siege engine - Wikipedia

A siege engine is a device that is designed to break or circumvent heavy castle doors, thick city walls and other fortifications in siege warfare. Some are immobile, constructed in place to attack enemy fortifications from a distance, while others have wheels to enable advancing up to the enemy fortification. There are many distinct types, such as siege towers that allow foot soldiers to scale walls and attack the defenders, battering rams that damage walls or gates, and large ranged weapons (such as ballistae, catapults/trebuchets and other similar constructions) that attack from a distance by launching projectiles. Some complex siege engines were combinations of these types.

Siege engines are fairly large constructions – from the size of a small house to a large building. From antiquity up to the development of gunpowder, they were made largely of wood, using rope or leather to help bind them, possibly with a few pieces of metal at key stress points. They could launch simple projectiles using natural materials to build up force by tension, torsion, or, in the case of trebuchets, human power or counterweights coupled with mechanical advantage. With the development of gunpowder and improved metallurgy, bombards and later heavy artillery became the primary siege engines.

Collectively, siege engines or artillery together with the necessary soldiers, sappers, ammunition, and transport vehicles to conduct a siege are referred to as a siege train.[1]





Ballista - Wikipedia

he ballista (Latin, from Greek βαλλίστρα ballistra[1] and that from βάλλω ballō, "throw"),[2] plural ballistae, sometimes called bolt thrower, was an ancient missile weapon that launched either bolts or stones at a distant target.

Developed from earlier Greek weapons, it relied upon different mechanics, using two levers with torsion springs instead of a tension prod (the bow part of a modern crossbow). The springs consisted of several loops of twisted skeins. Early versions projected heavy darts or spherical stone projectiles of various sizes for siege warfare. It developed into a smaller precision weapon, the scorpio,[3] and possibly the polybolos.

Greek weapon
Main article: Greek and Roman artillery
The early ballistae in Ancient Greece were developed from two weapons called oxybeles and gastraphetes. The gastraphetes ('belly-bow') was a handheld crossbow. It had a composite prod and was spanned by bracing the front end of the weapon against the ground while placing the end of a slider mechanism against the stomach. The operator would then walk forward to arm the weapon while a ratchet prevented it from shooting during loading. This produced a weapon that, it was claimed, could be operated by a person of average strength but which had a power that allowed it to be successfully used against armored troops. The oxybeles were a bigger and heavier construction employing a winch and were mounted on a tripod. It had a lower rate of fire and was used as a siege engine.

With the invention of torsion spring bundle technology, the first ballistae were built. The advantage of this new technology was the fast relaxation time of this system. Thus it was possible to shoot lighter projectiles with higher velocities over a longer distance. By contrast, the comparatively slow relaxation time of a tension machine such as the oxybeles meant that much less energy could be transferred to light projectiles, limiting the effective range of the weapon.

The earliest form of the ballista is thought to have been developed for Dionysius of Syracuse, c. 400 BC.

The Greek ballista was a siege weapon. All components that were not made of wood were transported in the baggage train. It would be assembled with local wood, if necessary. Some were positioned inside large, armored, mobile siege towers or even on the edge of a battlefield. For all of the tactical advantages offered, it was only under Philip II of Macedon, and even more so under his son Alexander, that the ballista began to develop and gain recognition as both a siege engine and field artillery. Historical accounts, for instance, cited that Philip II employed a group of engineers within his army to design and build catapults for his military campaigns.[4][5] There is even a claim that it was Philip II with his team of engineers who invented the ballista after improving Dionysius's device, which was merely an oversized slingshot.[6] It was further perfected by Alexander, whose own team of engineers introduced innovations such as the idea of using springs made from tightly strung coils of rope instead of a bow to achieve more energy and power when throwing projectiles.[6] Polybius reported about the usage of smaller, more portable ballistae, called scorpions, during the Second Punic War.

Ballistae could be easily modified to shoot both spherical and shaft projectiles, allowing their crews to adapt quickly to prevailing battlefield situations in real time.

As the role of battlefield artillery became more sophisticated, a universal joint (which was invented just for this function) was integrated into the ballista's stand, allowing the operators to alter the trajectory and firing direction of the ballista as required without a lengthy disassembly of the machine.

Roman weaponry
Main article: Roman siege engines

Reconstructed small Roman ballista

One talent ballista (26 kg [57 lb] weight projectile) was typical for Roman era ballista. The heaviest version ever made was built by Archimedes, and used stones up to three talents (78 kg [172 lb]).[7]

Roman 'catapult-nest' on Trajan's Column

Ballista bolt heads
After the absorption of the Ancient Greek city-states into the Roman Republic in 146 BC, the highly advanced Greek technology began to spread across many areas of Roman influence. This included the great military machine advances the Greeks had made (most notably by Dionysus of Syracuse), as well as all the scientific, mathematical, political and artistic developments.

The Romans adopted the torsion-powered ballista, which had by now spread to several cities around the Mediterranean, all of which became Roman spoils of war, including one from Pergamon, which was depicted among a pile of trophy weapons in relief on a balustrade.

The torsion ballista, developed by Alexander, was a far more complicated weapon than its predecessor and the Romans developed it even further, especially into much smaller versions, that could be easily carried.





De architectura - Wikipedia



De architectura (On architecture, published as Ten Books on Architecture) is a treatise on architecture written by the Roman architect and military engineer Marcus Vitruvius Pollio and dedicated to his patron, the emperor Caesar Augustus, as a guide for building projects. As the only treatise on architecture to survive from antiquity, it has been regarded since the Renaissance as the first known book on architectural theory, as well as a major source on the canon of classical architecture.[1]

It contains a variety of information on Greek and Roman buildings, as well as prescriptions for the planning and design of military camps, cities, and structures both large (aqueducts, buildings, baths, harbours) and small (machines, measuring devices, instruments).[2] Since Vitruvius published before the development of cross vaulting, domes, concrete, and other innovations associated with Imperial Roman architecture, his ten books give no information on these distinctive innovations of Roman building design and technology.[3]

From references to them in the text, we know that there were at least a few illustrations in original copies (perhaps eight), but none of these survived in medieval manuscript copies. This deficiency was remedied in 16th-century printed editions, which became illustrated with many large plates.

Origin and contents
Probably written between 30-20 BC,[4] it combines the knowledge and views of many antique writers, Greek and Roman, on architecture, the arts, natural history and building technology. Vitruvius cites many authorities throughout the text, often praising Greek architects for their development of temple building and the orders (Doric, Ionic and Corinthian), and providing key accounts of the origins of building in the primitive hut.

Though often cited for his famous "triad" of characteristics associated with architecture – utilitas, firmitas and venustas (utility, strength and beauty) – the aesthetic principles that influenced later treatise writers were outlined in Book III. Derived partially from Latin rhetoric (through Cicero and Varro), Vitruvian terms for order, arrangement, proportion, and fitness for intended purposes have guided architects for centuries, and continue to do so.

The Roman author gives advice on the qualifications of an architect (Book I) and on types of architectural drawing.[5]

The ten books or scrolls are organized as follows:

De architectura – Ten Books on Architecture

Town planning, architecture or civil engineering in general, and the qualifications required of an architect or the civil engineer
Building materials
Temples and the orders of architecture (includes the section on body proportions that led to da Vinci's drawing)
continuation of book III
Civil buildings
Domestic buildings
Pavements and decorative plasterwork
Water supplies and aqueducts
Sciences influencing architecture – geometry, measurement, astronomy, sundial
Use and construction of machines – Roman siege engines, water mills, drainage machines, Roman technology, hoisting, pneumatics
Roman architects were skilled in engineering, art, and craftsmanship combined. Vitruvius was very much of this type, a fact reflected in De architectura. He covered a wide variety of subjects he saw as touching on architecture. This included many aspects that may seem irrelevant to modern eyes, ranging from mathematics to astronomy, meteorology, and medicine. In the Roman conception, architecture needed to take into account everything touching on the physical and intellectual life of man and his surroundings.

Vitruvius, thus, deals with many theoretical issues concerning architecture. For instance, in Book II of De architectura, he advises architects working with bricks to familiarise themselves with pre-Socratic theories of matter so as to understand how their materials will behave. Book IX relates the abstract geometry of Plato to the everyday work of the surveyor. Astrology is cited for its insights into the organisation of human life, while astronomy is required for the understanding of sundials. Likewise, Vitruvius cites Ctesibius of Alexandria and Archimedes for their inventions, Aristoxenus (Aristotle's apprentice) for music, Agatharchus for theatre, and Varro for architecture.

Buildings

Greek house plan after Vitruvius
Vitruvius sought to address the ethos of architecture, declaring that quality depends on the social relevance of the artist's work, not on the form or workmanship of the work itself. Perhaps the most famous declaration from De architectura is one still quoted by architects: "Well building hath three conditions: firmness, commodity, and delight". This quote is taken from Sir Henry Wotton's version of 1624, and accurately translates the passage in the work, (I.iii.2) but English has changed since then, especially in regard to the word "commodity", and the tag may be misunderstood. In modern English it would read: "The ideal building has three elements; it is sturdy, useful, and beautiful."

Vitruvius also studied human proportions (Book III) and this part of his canones were later adopted and adapted in the famous drawing Homo Vitruvianus ("Vitruvian Man") by Leonardo da Vinci.

Domestic architecture
While Vitruvius is fulsome in his descriptions of religious buildings, infrastructure and machinery, he gives a mixed message on domestic architecture. Similar to Aristotle, Vitruvius offers admiration for householders who built their own homes without the involvement of an architect.[6][7] His ambivalence on domestic architecture is most clearly read in the opening paragraph of the Introduction to Book 6.[8] Book 6 focusses exclusively on residential architecture but as architectural theorist Simon Weir has explained, instead of writing the introduction on the virtues of residences or the family or some theme related directly to domestic life; Vitruvius writes an anecdote about the Greek ethical principle of xenia: showing kindness to strangers.[9]

Roman technology

A Roman ballista

The Pont du Gard Roman aqueduct in southern France.
De architectura is important for its descriptions of many different machines used for engineering structures, such as hoists, cranes, and pulleys, as well as war machines such as catapults, ballistae, and siege engines. Vitruvius also described the construction of sundials and water clocks, and the use of an aeolipile (the first steam engine) as an experiment to demonstrate the nature of atmospheric air movements (wind).

Aqueducts and mills
Books VIII, IX, and X of De architectura form the basis of much of what is known about Roman technology, now augmented by archaeological studies of extant remains, such as the Pont du Gard in southern France. Numerous such massive structures occur across the former empire, a testament to the power of Roman engineering. Vitruvius's description of Roman aqueduct construction is short, but mentions key details especially for the way they were surveyed, and the careful choice of materials needed.

His book would have been of assistance to Frontinus, a general who was appointed in the late 1st century AD to administer the many aqueducts of Rome. Frontinus wrote De aquaeductu, the definitive treatise on 1st-century Roman aqueducts, and discovered a discrepancy between the intake and supply of water caused by illegal pipes inserted into the channels to divert the water. The Roman Empire went far in exploiting water power, as the set of no fewer than 16 water mills at Barbegal in France demonstrates. The mills ground grain in a very efficient operation, and many other mills are now known, such as the much later Hierapolis sawmill.

Materials
Vitruvius described many different construction materials used for a wide variety of different structures, as well as such details as stucco painting. Cement, concrete, and lime received in-depth descriptions, the longevity of many Roman structures being mute testimony to their skill in building materials and design.


Design for an Archimedean water screw
He advised that lead should not be used to conduct drinking water, clay pipes being preferred. He comes to this conclusion in Book VIII of De architectura after empirical observation of the apparent laborer illnesses in the plumbum (lead pipe) foundries of his time. However, much of the water used by Rome and many other cities was very hard, minerals soon coated the inner surfaces of the pipes, so lead poisoning was reduced.

Vitruvius related the famous story about Archimedes and his detection of adulterated gold in a royal crown. When Archimedes realized the volume of the crown could be measured exactly by the displacement created in a bath of water, he ran into the street with the cry of "Eureka!", and the discovery enabled him to compare the density of the crown with pure gold. He showed the crown had been alloyed with silver, and the king was defrauded.

Dewatering machines

Drainage wheel from Rio Tinto mines

Sequence of drainage wheels found in Rio Tinto
Vitruvius described the construction of the Archimedes' screw in Chapter 10, although did not mention Archimedes by name. It was a device widely used for raising water to irrigate fields and dewater mines. Other lifting machines mentioned in De architectura include the endless chain of buckets and the reverse overshot water-wheel. Remains of the water wheels used for lifting water have been discovered in old mines such as those at Rio Tinto in Spain and Dolaucothi in west Wales. One of the wheels from Rio Tinto is now in the British Museum, and one from the latter in the National Museum of Wales. The remains were discovered when these mines were reopened in modern mining attempts. They would have been used in a vertical sequence, with 16 such mills capable of raising water at least 96 feet (29 m) above the water table. Each wheel would have been worked by a miner treading the device at the top of the wheel, by using cleats on the outer edge. That they were using such devices in mines clearly implies that they were entirely capable of using them as water wheels to develop power for a range of activities, not just for grinding wheat, but also probably for sawing timber, crushing ores, fulling, and so on.

Force pump
Ctesibius is credited with the invention of the force pump, which Vitruvius described as being built from bronze with valves to allow a head of water to be formed above the machine. The device is also described by Hero of Alexandria in his Pneumatica. The machine is operated by hand in moving a lever up and down. He mentioned its use for supplying fountains above a reservoir, although a more mundane use might be as a simple fire engine. One was found at Calleva Atrebatum (Roman Silchester) in England, and another is on display at the British Museum. Their functions are not described, but they are both made in bronze, just as Vitruvius specified.

Vitruvius also mentioned the several automatons Ctesibius invented, and intended for amusement and pleasure rather than serving a useful function.

Central heating

Ruins of the hypocaust under the floor of a Roman villa: The part under the exedra is covered.
Vitruvius outlined the many innovations made in building design to improve the living conditions of the inhabitants. Foremost among them is the development of the hypocaust, a type of central heating where hot air developed by a fire was channelled under the floor and inside the walls of public baths and villas. He gave explicit instructions on how to design such buildings so fuel efficiency is maximized; for example, the caldarium is next to the tepidarium followed by the frigidarium. He also advised using a type of regulator to control the heat in the hot rooms, a bronze disc set into the roof under a circular aperture, which could be raised or lowered by a pulley to adjust the ventilation. Although he did not suggest it himself, his dewatering devices such as the reverse overshot water-wheel likely were used in the larger baths to lift water to header tanks at the top of the larger thermae, such as the Baths of Diocletian and the Baths of Caracalla.

Surveying instruments
That Vitruvius must have been well practised in surveying is shown by his descriptions of surveying instruments, especially the water level or chorobates, which he compared favourably with the groma, a device using plumb lines. They were essential in all building operations, but especially in aqueduct construction, where a uniform gradient was important to provision of a regular supply of water without damage to the walls of the channel. He described the hodometer, in essence a device for automatically measuring distances along roads, a machine essential for developing accurate itineraries, such as the Peutinger Table.

Sea level change
In Book IV Chapter 1 Subsection 4 of De architectura is a description of 13 Athenian cities in Asia Minor, "the land of Caria", in present-day Turkey. These cities are given as: Ephesus, Miletus, Myus, Priene, Samos, Teos, Colophon, Chius, Erythrae, Phocaea, Clazomenae, Lebedos, Mytilene, and later a 14th, Smyrnaeans. Myus, the third city, is described as being "long ago engulfed by the water, and its sacred rites and suffrage". This sentence indicates, at the time of Vitruvius's writing, it was known that sea-level change and/or land subsidence occurred. The layout of these cities is in general from south to north so that it appears that where Myrus should be located is inland. If this is the case, then since the writing of De architectura, the region has experienced either soil rebound or a sea-level fall. Though not indicative of sea-level change, or speculation of such, during the later-empire many Roman ports suffered from what contemporary writers described as 'silting'. The constant need to dredge ports became a heavy burden on the treasury and some have speculated that this expense significantly contributed to the eventual collapse of the empire. Roman salt works in Essex, England, today are located at the five-metre contour, implying this was the coastline.[10][11] These observations only indicate the extent of silting and soil rebound affecting coastline change since the writing of De architectura.