Ancient hydraulic technology

Issues concerning the correct disposal of wastewater had been faced in Antiquity since the beginning of the first urban settlements. Technically advanced sewage systems were built as early as in 2nd and 3rd millennium B.C., but it is only in the 7-6 century B.C. that many examples of hierarchically organized sewers, serving the whole extensions of urban settlement in order to draw wastewater outside the city, can be recorded. The credit for the recollection of the greatness and efficiency of the Roma sewers is due to several literary sources, such as Pliny the Elder, Dionysius of Halicarnassus and Livy. Rome was equipped with a sewer network since the 6th century A.D.: extensive restoration works are attested as early as the 2nd century and during the time of Augustus the curatores were in charge for the urban water management. The present paper deals with an examination of the characters of the sewer channels – tributaries to the Cloaca Maxima – located in the Imperial For a and those in other important settlements in Italy (such as Ostia and Pompeii), in Greece, in Asia Minor and in the whole Roman Empire. In these places the several types of channels and the building techniques used not only met the needs related with climates and environments, but they are as well the proof of the wide spreading of hydraulic knowledges.

The aim is to study ancient fountains in their architectural context, in the belief that the context will reveal their function in the dwelling.  This article first analyzes the fountain structures and examines the relationship between each structure and the architecture. Through this approach, it is possible to reach some conclusions of more general value, concerning the function of central parts of Roman houses.

This article presents a new perspective on both the relative and absolute dating of the various components of the Siloam Water System. The Siloam Tunnel, part of the Siloam Water System, known as Hezekiah’s Tunnel since the 19th cent. C.E., has given rise to a number of unsolved enigmas, for example its scope and the level of technical and engineering capability, as well as the cryptic Siloam Inscription found within the tunnel. The Siloam Tunnel has been generally attributed to Hezekiah, the Judean king who faced a siege from Sennacherib in 701 B.C.E., and it is commonly accepted that Hezekiah built it as a defensive measure in preparation for the impending siege. Recently, REICH and SHUKRON 1 have proposed that the Siloam Tunnel should be dated to the early part of the 8th cent. B.C.E., thus implying that the ‘Hezekiah Tunnel’ actually predated Hezekiah by approximately one hundred years. However, they do not consider its raison d’eˆtre or whether the technological knowhow required for such a complicated project was available during that period. While this paper agrees with the proposal that the Siloam Tunnel cannot be attributed to Hezekiah, I rather date it several hundred years later, based on engineering, archaeological, historic, palaeographic and epigraphic evidence. Nevertheless, it is assumed that Hezekiah did initiate a major water-provision project in anticipation of the siege; hence an identification of his emergency preparatory activity for the siege is hereby proposed.

Presentazione del volume
OPERE DI REGIMENTAZIONE DELLE ACQUE IN ETÀ ARCAICA.
ROMA, GRECIA E MAGNA GRECIA, ETRURIA E MONDO ITALICO,
a cura di Elisabetta Bianchi e Matteo D’Acunto
I relatori, tre illustri docenti universitari, D. Mertens, P. Liverani, F. Napolitano, esamineranno, da differenti prospettive quale sia il contributo alla conoscenza della storia, della topografia e della tecnologia antica offerto dai saggi raccolti nel volume che affronta, a partire dall’archeologia e in una visuale storica e interdisciplinare, lo studio delle opere di regimentazione delle acque, infrastrutture realizzate in epoca arcaica su scala urbana contestualmente alla formazione dei più importanti centri del Mediterraneo.
Tali opere furono finalizzate al miglioramento della vita della comunità, perché pensate e progettate per controllare i ricorrenti fenomeni alluvionali, per irreggimentare le acque reflue in ambito cittadino e per bonificare aree del territorio strategicamente importanti, ma paludose. Punto di partenza sono i recenti studi condotti a Roma sulla Cloaca Massima, che hanno permesso di chiarire quale fosse l’originario aspetto della monumentale opera idraulica attribuita ai re etruschi, nonché le ultime indagini archeologiche a Cuma, che hanno messo in luce il confronto più stringente con l’opera dell’Urbe, per la struttura del condotto a doppio canale.
Numerosi studiosi di varie discipline contribuiscono nel volume a rappresentare lo stato della conoscenza sui modi della regimentazione delle acque di età arcaica, i cui temi centrali, che consentono di ricomporne l’identità, sono: la geomorfologia, il contesto storico, l’impegno costruttivo in termini di forza lavoro, la funzione, le tecniche di costruzione, la trasmissione di saperi ingegneristici, gli aspetti terminologici e la valenza delle opere.
In una prima sezione sono raccolti i contributi relativi agli interventi realizzati in Grecia, Magna Grecia e Sicilia, con approfondimenti specifici sui problemi dell’urbanistica e delle tirannidi arcaiche. La seconda sezione, che ha per argomento l’Etruria e il Latium Vetus, contiene uno sguardo approfondito sulle tecniche costruttive e sui sistemi di drenaggio. Nella terza sezione, dedicata a Roma, molti dei contributi focalizzano l’attenzione sulla bonifica della valle del Velabro e sulla costruzione del condotto idraulico nel contesto storico di età regia, più tardi noto come Cloaca Massima.
L'evento potrà essere seguito sul piattaforma Google-MEET (link: meet.google.com/oin-wdvf-isz)

It is hereby proposed that the Romans were directly involved in several major engineering projects which were carried out in Judea. These projects included the architectural planning of Herod's Temple in Jerusalem, the use of Hydraulic Pozzolanic Mortar in the Caesarea harbor and the simultaneous cutting of the Siloam Tunnel in Jerusalem. The complexity of these projects called for highly professional and experienced engineers. It is further proposed that the planning of Herod’s Jerusalem temple and the availability and use of hydraulic pozzolanic mortar in the Caesarea marine harbor are to be attributed to Marcus Vipsanius Agrippa who was a senior Roman architect and a close friend of Herod the Great.

ABSTRACT
Under the church of Santa Sabina in Rome one finds a net of tunnels dug from the beginning of the second century BC, in order to provide water to the inhabitants of the Aventino Hill. Between the end of the 19th and the beginning of the 20th century, these tunnels have been investigated many times and, in some cases, restored. In 2005 the Authors and a team of the Egeria Center for Speleologic Researches have visited and investigated the deepest levels, part of which was not found any more. In the paper we give a geologic description of the Aventino Hill, a short history of the settlements in the area, and new hypotheses on the underground structure and on how it was carried out.
Keywords: Rome, Santa Sabina, Aventino Hill, water tunnels, Appia acqueduct

Riassunto
Sotto la chiesa di Santa Sabina, in Roma, si estende una rete di cunicoli realizzati a partire dal II secolo a.C. per l’approvigionamento idrico delle abitazioni presenti sul Colle Aventino. Tra la fine dell’800 e l’inizio del ‘900 tali cunicoli sono stati più volte indagati e in alcuni casi restaurati. Nel 2005 gli Autori e una equipe del CRS “Egeria” hanno potuto rivedere e studiare gli ambienti più profondi, documentandone anche la parziale scomparsa. Nell’articolo viene tracciato un profilo geologico del Colle Aventino, una breve storia degli insediamenti presenti nell’area e vengono formulate nuove ipotesi sulla struttura sotterranea e sulla sua realizzazione.   
Parole chiave
Roma, Santa Sabina, Aventino, cunicoli idraulici, acquedotto Appio

Proceedings of the First International Summer School “Hydraulic Systems In The Roman World” (Feltre, 25th - 29th August 2014)

Materiali della prima International Summer School “Hydraulic Systems In The Roman World” (Feltre, 25-29 Agosto 2014)

ISBN: 978-88-99369-64-4

Public goods are "non-excludable" and "non-rivalrous" resources, including roads, water management systems, and plazas, as well as "symbolic public goods," such as religious architecture and social identity. Public goods occur in greater abundance in cities with more cooperative and inclusive forms of organization, which seems to undermine arguments that elites constructed them to augment their power. Such goods are major "pull" factors drawing migration to modern cities, but ancient cities also had public goods that likely attracted immigrants, increasing their population and diversity. We examine these ideas at Middle Preclassic-period (cal 800-300 BC) Nixtun-Ch'ich', in Petén, Guatemala. This city and other Preclassic metropoles in the Maya lowlands seem to have been on the more-cooperative end of a cooperative-competitive spectrum, compared to most cities of the Classic period (AD 200-900). We also speculate about how symbolic public goods were coopted to create a more exclusive social system in the Late Preclassic period (300 BC-AD 200).

De Miranda Adriana

Anno di Edizione: 2018
Edizione: L'ERMA di BRETSCHNEIDER
Collane:
Studia Archaeologica, 224
Il volume affronta lo studio delle fonti antiche che hanno testimoniato l' uso e l' importanza delle fontane a sorpresa, piccole fontane da tavolo, o da collocarsi al centro di cortili, invenzioni di età ellenistica, capaci di suscitare meraviglia per l' ingegnosità di meccanismi nascosti che, tramite l' applicazione pratica di princìpi della fisica, permettono spettacolari giochi d' acqua. Attraverso l' analisi delle fonti, si è cercato di dimostrare quanto l' arte dell' ingegnere dell' antica Grecia, nell' impiegare il suo sapere tecnologico, abbia avuto un ruolo fondamentale nella evoluzione degli autòmata idraulici, dalla società ellenistica a quella rinascimentale, anche attraverso la mediazione dell' ingegneria araba, e sia stato imprescindibile per l' elaborazione di metodi e processi innovativi.

Adriana de Miranda architetto e storica dell' arte, si è laureata in architettura presso il Politecnico di Milano e specializzata in storia dell' arte medievale e moderna presso l' Università Cattolica del Sacro Cuore di Milano. Ha conseguito un PhD in arte ed architettura islamica presso la School of Oriental and African Studies (SOAS) di Londra. La sua ricerca è incentrata sulla storia dell' architettura del Mediterraneo e del paesaggio e sulle tipologie idrauliche di antica tradizione. Per l' Erma di Bretschneider ha pubblicato Water Architecture in the lands of Syria: the Water-Wheels (2007) e L' hammam nell' Islam occidentale fra l' VIII e il XIV secolo (2010).

The fact that private fountains surpass public fountains greatly in number is one of the conclusions of this paper, which also concerns the delivered quantity of water.  The private fountains, and the revelation of their non-domestic display function, have produced knowledge that is incompatible with the modern urbanistic approach of how water supply to an ancient city should be viewed and understood.

Τὸ ὕδωρ ἑτέρωσε τρέψας: Stream diversion in Megara. 
The excavation at Stayrakis’ plot in the north east part of Megara revealed an extensive cemetery dated from late 8th to the early 1st c. B.C. Furthermore, a rock-cut well to the south west, and the south bank of a stream to the north part of the plot were excavated. The placing of graves into the bank of the stream led us to examine the possibility of a stream drainage or/and diversion. In this paper the archaeological and historical data help us to initiate this hydraulic work into the building program of the first half of the 5th c. B.C.

We study the methods of supply, collection, conduction and distribution of water in the Iberian settlements. Archaeological remains and literary sources help us to analyze the water system of an Iberian town. We also show the functions that the water plays in different aspects of the Iberian society, even the economic, anthropological, religious and cultural ones.

Julia Shaw & John Sutcliffe, 2005. 'Ancient Dams and Buddhist Landscapes
in the Sanchi area: New evidence on Irrigation, Land use and Monasticism in Central India, South Asian Studies, 21:1, 1-24,
To link to this article: https://doi.org/10.1080/02666030.2005.9628641


This paper discusses 16 irrigation works in the vicinity of the UNESCO World Heritage Buddhist site of Sanchi in Madhya Pradesh, India. Methodologies for reconstructing reservoir volumes, areas, together with hypotheses regarding associated landuse and relationships with nearby Buddhist complexes were discussed in previous papers (Shaw and Sutcliffe 2001, 2003).  This paper presents the results of intensive field investigations at three reservoir complexes in the study area: i) The main reservoir at Sanchi, at the centre of the study area, which also comprises two smaller dams, Karondih and Dargawan in the short valleys to the west; ii) Ferozpur, about 11 km further west; and 'iii) Devrajpur, in the eastern part of the study area.  These reservoir sites represent a cross-section, both in terms of chronology and design, of the total regional group.  Further, their distribution over two quite distinct ecological zones holds the possibility of illuminating relationships between reservoir design and topography.  Contour mapping combined with high resolution satellite imagery helped to clarify uncertainties about the relationship between upstream and downstream levels, provided a check on earlier reservoir volume/area calculations and inferences about land use, while renewed field based survey work shed new light on the position of spillways and sluices. Renewed mapping at nearby Buddhist monastic sites was geared towards developing a typology of local monastery and stupa forms. It also helped to assess further our earlier hypotheses (Shaw and Sutcliffe 2001) regarding the ties between religion and water / land governmentality.

In the Velabro flowed the Spinon, a tributary of the Tiber, which for extreme rains could reach flow rates of 10 m3/s. The valley was filled with alluvial silts deposed, more than by the Spinon, by the Tiber that flooded the valley. A long stretch of the monumental hypogeum designed by Tarquinius Priscus and completed by Tarquinius Superbus, remains below the Roman Forum. The visible structures, made in cappellaccio, were part of a duct with two parallel tunnels covered with a "false vault" which, reworked several times, is known as Cloaca Massima. New research allows to better define its path in the Forum area, and to hypothesize the terminal trajectory of the conduit closed to the Tiber, before the reworkings of the republican age. The functional and typological definition allows the comparison with double tunnel hydraulic works for water regulation, made in the archaic period in other ancient Mediterranean cities, affected by geomorphological conditions that required reclamation works.

La documentation du «Glossarium Mediae Latinitatis Cataloniae», composée par des textes écrits entre le IXe et le XIIe siècles, nous donne l’occasion de concevoir et recréer l’aménagement d’un territoire soit rural, soit urbain. L’étude de ces textes nous permet d’affirmer que l’un des facteurs qui déterminent cette organisation est justement l’eau et, en particulier, l’usage des sources et des artères fluviales naturelles, le détournement des cours d’eau et, surtout, l’utilisation de la force motrice que l’eau génère. Dans ce sens, le moulin est une des constructions qui, par excellence, reflète tout l’effort technique que les hommes de l’époque ont pu développer. Le moulin machine à moudre, le moulin et les parties que le composent, les mécanismes qui permettent son fonctionnement, la maison ou le bâtiment qui l’abrite, tout est cité, décrit ou recensé dans le corpus du glossaire. On peut aussi y lire des cas de concessions pour la construction, des discussions sur le fonctionnement ou des accords sur les bénéfices qui découlent de l’exploitation. Tout cela sans jamais oublier que le vocabulaire qui se rapporte au moulin tourne toujours, comme son propre mouvement, autour de l’eau.

This paper focuses on the water culture in Crete during the Ottoman period by studying its impact  on  the  city  of  Rethymno  (1646  -  1898).  First,  I  present  the  key  features  of  the  water distribution system as applied in the Ottoman empire, looking for its predecessors and infuences from past cultures. Secondly, I present the importance of the fountain as an important element of a city and its public space, baring the role of a “hot spot” for socialisation.  Then I present the water supply system of Rethymno during the Venetian and the Ottoman era.
This comparative approach reveals the technical expertise of the construction of aqueducts transferred from  one  culture  into  the  other  as  well  as  the  engineering  breakthroughs  undertook  during  the Ottoman period. In the framework of this study, I describe the plan of Engineer Michael Savvakis conducted for the Ottoman state during the years  1892-1893, while looking for its traces along the city. Further  on,  I  present  the  main  public  and  private  end-members  of  the aqueducts,  such  as fountains and baths in the city of Rethymno. As a final step, I study the transition from the Ottoman state  towards  the  Greek  state  in  regard  to  the  infrastructures  which  have  been  integrated  to  the functions of this new state. Finally, I conclude on the status of engineering skills during the Ottoman empire as implemented in Rethymno.

This paper presents the results of the ‘Roman Barcino Water Network’ Project. This study employed a series of methodologies aiming at joining and interpreting all data available on water supply, distribution, management, use and discharge in the Roman colony of Barcino (modern Barcelona). Analyses of the results substantially modified previous knowledge of Barcino’s water organization and provided one of the few examples in which the whole water system of a Roman city has been tackled. We concluded that the water supply employed a single aqueduct, which divided before entering the city and not two of them as it was previously assumed. Barcino’s water distribution system was designed according to the different uses of water and was conditioned by the city’s particular topography. The results also stress the colony’s ample water availability, which despite its small size, allowed the maintenance of multiple public and private baths as befitted an accommodated population of merchants and administrators.

Among the ancient irrigation practices, the Sri Lankan dry zone water management systems sustained for over 2000 years have been well documented. With the influx of communities settling around the historical urban centers, efficient water management was necessary. The invention of the Tank Cascaded system (TCS) and a network of canal systems have emerged to supply water to these centers, which lasted even at present. This paper aims at unraveling some unique functions of the Yoda Ela (YE) canal located in the northern dry zone connecting Kala Wewa (reservoir) with Tissa Wewa. After examining the aerial photographs, Google Earth Pro, and Digital Elevation Models (DEM) followed by field investigations to assess the respective environmental changes, it was evident that the water supply from a transboundary canal took place with the utmost

The authors explore aspects of a well uncovered at Tel Tsaf, Israel, dating to the Middle Chalcolithic
Period, ca. 4800 cal b.c. The well was uncovered in close proximity to the settlement of Tel
Tsaf, shedding light on the hydraulic technology of the community. An exceptionally rich assemblage
of complete vessels has been found in situ at the bottom of the shaft. The ceramics show two
distinct typological features uncommon to other assemblages of the Middle Chalcolithic: double
paired handles and the so-called beakers, a new ceramic shape dominant in this assemblage. We
argue that the ceramic assemblage comprises task-specific vessel shapes designed for drawing water
from a well. The examples from Tel Tsaf are currently the earliest of their kind.

This paper presents the results of the ‘Roman Barcino Water Network’ Project. This study employed a series of methodologies aiming at joining and interpreting all data available on water supply, distribution, management, use and discharge in the Roman colony of Barcino (modern Barcelona). Analyses of the results substantially modified previous knowledge of Barcino’s water organization and provided one of the few examples in which the whole water system of a Roman city has been tackled. We concluded that the water supply employed a single aqueduct, which divided before entering the city and not two of them as it was previously assumed. Barcino’s water distribution system was designed according to the different uses of water and was conditioned by the city’s particular topography. The results also stress the colony’s ample water availability, which despite its small size, allowed the maintenance of multiple public and private baths as befitted an accommodated population of merchants a...

Abstract
The Virgin acqueduct is one of the 11 acqueducts that carried water to Rome and is the only one which, since it was implemented by Agrippa in the year 19 b.p.e., has never ceased to function. It originates at Salone, on the Collatina Way east of Rome, where, by means of water collecting cuniculi, it drains most of its flow. The specus is 20 Km long and it develops almost entirely underground. The acqueduct gets inside town from the north, crosses the Nomentana Way, goes under Villa Glori, the Parioli and Pincio hills, finally heading for Campo Marzio where, since 1762, it also feeds the well-known Trevi Fountain. From the XVI century, the underground channel of the Virgin acqueduct has excited the interest of the inhabitants of the Pincio hill. First the Order of the Minimi of Saint Francis from Paola and after the Ricci and Medici families tried, in various ways, to make use of it to solve the problems due to the lack of water in the hill area above; over the centuries, al least two wells were dug to raise water mechanically, together with a flight for water transport on animals. In this paper we consider the various systems that have been investigated and mapped during tens of inspections and, even if many elements of evaluation are missing, we describe the possible systems for water raising from the underground channel, by means of hydraulic wheels and piston pumps. Finally, we discuss two other systems for drawing water, recently discovered near the College Saint Nazarenus and in Alibert street.

Keywords: Virgin acqueduct, Pincio hill, Rome.

L'Insula del Centenario (Pompei, IX 8, 3.6) è oggetto di studio da parte del Programma Vesuviana dell'Università di Bologna dal 1998, caratterizzato da un approccio multidisciplinare nell'analisi e nella documentazione dei rivestimenti decorativi, sia pittorici che musivi. Fra i suoi ambienti, uno dei più significativi in termini di complessità del programma decorativo, sia pittorico che musivo, è il viridarium 33 (fig 1). Probabilmente scoperto, l'ambiente è posto lungo il lato meridionale dell'ampio giardino a peristilio. Al suo interno, un alto criptoportico ad L ne occupa i lati ovest e sud, il cui piano è lievemente inclinato verso il centro della stanza e su cui si dispongono cinque tegole a comignolo: su di esso, in posizione centrale ed in asse con il taglio della porta di ingresso all'ambiente, è un'edicola absidata, all'interno della quale solo ipotetica è la collocazione di una statuetta di Ermafrodito in marmo bianco (Coralini 2017, 291-293, n. 200). L'interno dell'edicola presenta un rivestimento in fritta egizia nel catino ed in pietra pomice nella parte inferiore, mentre l'esterno presenta un rivestimento musivo di tessere in pasta vitrea: sul frontone un motivo interpretato variamente ora come cespo di acanto (PPM IX, 992, V. Sampaolo) ora come testa di Oceano (Santoro et alii 2005, 541). Dalla base dell'edicola si innesta la scaletta rivestita di lastre in marmo di restauro («rimesse dalla Direzione degli scavi sulle tracce del rivestimento antico»: Mau 1881, 222), affiancata da due paraste rivestite da intonaco giallo con lumeggiature, a imitazione del marmo numidico. Antistante la scaletta, un bacino rettangolare, rivestito in cocciopesto intonacato di azzurro e contornato da un bordo, nel cui angolo nord-est è una canaletta del troppo pieno, orientata in direzione di un piccolo foro passante, alla base della parete est, quasi in posizione centrale: il drenaggio del troppo pieno dal bacino del ninfeo doveva essere probabilmente favorito dall'inclinazione ovest-est, comune a tutte le superfici orizzontali dell'ambiente (Sassi 2017: 503). Tale drenaggio permetteva quindi il passaggio dell'acqua dal viridarium ai quartieri servili, dove probabilmente veniva raccolta e impiegata per scopi pratici. Il programma decorativo pittorico interessa tutte le pareti dell'ambiente, compreso il criptoportico, e si presenta tripartito in senso orizzontale. La zona superiore accoglie, lungo le pareti nord, est ed ovest, pitture di giardino entro lesene rosse, con labra quadrati su supporti configurati in forma di sfingi, mentre la parete sud mostra scene di lotta fra fiere: nel settore est, un toro è aggredito da una belva, mentre in quello ovest, un felino maculato atterra un cavallo. All'estrema destra, un cinghiale in corsa emerge dalla vegetazione. La zona mediana presenta temi legati principalmente al mondo acquatico: le pareti nord, est ed ovest sono decorati con ambienti lacustri, mentre nella sud sono scene di lotta fra animali marini (a est, fra un polpo e una murena; a ovest, fra un'aragosta e una murena). La zona inferiore presenta una balaustra marmorea, con ghirlande ed uccelli. L'obiettivo del pittore è quindi palesemente quello di far credere all'osservatore di essere completamente immerso all'interno di un paràdeisos urbano, rafforzando l'impatto illusionistico grazie alla presenza, visiva e sonora, dell'acqua. Un primo specchio d'acqua era probabilmente dato da quello che naturalmente si raccoglieva sulla superficie superiore del criptoportico, alle spalle dell'edicola del ninfeo, in seguito alle piogge, essendo l'ambiente, come visto, verosimilmente scoperto. L'acqua qui raccolta non doveva superare lo spessore di un sottile velo, data la presenza drenante, sopra descritta, non solo di cinque tegole a comignolo, ma anche di due segmenti di fistulae di scarico, inserite nel registro mediano, all'altezza delle lotte di animali marini. La presenza dell'acqua in questo punto, non visibile all'osservatore, era però percepibile grazie ai riverberi di luce che si proiettavano sulle pitture di giardino del registro mediano, conferendogli un aspetto maggiormente realistico e vibrante. Inoltre le fistulae di scarico-oltre ad impedire che un accumulo d'acqua potesse a defluire all'interno del corridoio del criptoportico-ricoprivano anche un ruolo decorativo, permettendo all'osservatore di associare l'immagine dei due piccoli getti d'acqua naturale alle scene marine maggiormente in vista. Il flusso d'acqua principale, che si generava al centro dell'edicola del ninfeo, per poi riversarsi sull'alta scaletta in marmo e confluire all'interno del bacino antistante, era anch'esso ideato per avere un rapporto funzionale e iconografico con le pitture: alla base della scaletta era infatti una rappresentazione di una divinità fluviale recumbente, col braccio destro poggiato su di un'urna, mentre nella mano sinistra reggeva un ramo di canna. Identificata come il dio Sarno (PPM IX, 992, V. Sampaolo), l'immagine è quasi del tutto evanida, ma preservata da un noto acquerello di L. Bazzani (fig. 2). Quando il ninfeo era in funzione, il flusso d'acqua rivestiva completamente la divinità fluviale, suggerendo all'osservatore, anche in questo caso, associazioni semantiche fra acque dipinte ed acque reali. Se il ninfeo non era attivo, l'immagine del dio, in stretta prossimità con bacino d'acqua, si rifletteva al suo interno, creando un rapporto di sdoppiamento dell'immagine recentemente riconosciuto e indagato, anche per le sculture. Risulta quindi fondamentale sottolineare quanto la viva presenza dell'acqua all'interno dell'ambiente, prevista nel suo stato sia discendente e attivo che statico e riflettente, influenzasse non solo i temi iconografici scelti per decorarne le pareti, ma anche la destinazione d'uso stessa che il proprietario della casa aveva scelto per il viridarium e dell'impatto, visivo ed emotivo, che intendeva suscitare nei suoi fortunati ospiti.

Le site archéologique de Tahouda se trouve à la lisère méridionale des Aurès sur la rive ouest du Oued Biraz. Il occupe cet emplacement stratégique depuis la plus haute antiquité et dure jusqu'à la période médiévale. L'endroit est marqué par la grande bataille, opposant les troupes militaires de Koceila et celles de Okba ben Nafa'a, qui s'est terminé par la mort de ce dernier. Selon les auteurs anciens, la ville de Thabudeos était célèbre et urbanisée. Elle faisait partie du grand système de l'antique limes. Par la suite, le centre d'intérêt s'est tourné vers la tombe et la mosquée de Sidi Okba. Il ne reste actuellement que du site protégé à Tahouda, visible à travers la panoplie des koudiats, et faubourgs. Depuis 2004, on a découvert, soit par des prospections ou par des fouilles, des indices importants, attestant de l'occupation du territoire. Nous citerons comme exemple les carrières de pierres, les aqueducs, des éléments architectoniques de belle facture et la forteresse.