The Tunnel of Eupalinos or Eupalinian aqueduct (in Greek: Efpalinion orygma - Ευπαλίνιον όρυγμα) is a tunnel of 1,036 m (3,399 ft) length in Samos, Greece, built in the 6th century BC to serve as an aqueduct. The tunnel is the second known tunnel in history which was excavated from both ends (Ancient Greek: αμφίστομον, romanized: amphistomon, "having two openings"), and the first with a geometry-based approach in doing so. Today it is a popular tourist attraction.
|Tunnel of Eupalinos|
|Location||Samos Island, Greece|
|Opened||ca. 6th century BC|
In the sixth century BC, Samos was ruled by the famous tyrant Polycrates. During his reign or according to the local guides before his reign, two groups working under the direction of the engineer Eupalinos from Megara dug a tunnel through Mount Kastro to build an aqueduct to supply the ancient capital of Samos (today called Pythagoreion) with fresh water. This was of the utmost defensive importance; because the aqueduct ran underground, it could not easily be found by an enemy, who might otherwise cut off the water supply. The Eupalinian aqueduct was used for hundreds of years as an aqueduct then later as a defensive shelter, as proved from archaeological findings. It was rediscovered in 1882-1884 and today is open to visitors.
The Eupalinian aqueduct is described by Herodotus (Histories 3.60), without whom it might not have been discovered:
The tunnel took water from an inland spring, which was roofed over and thus concealed from enemies. A buried channel, with periodic inspection shafts, winds along the hillside to the northern tunnel mouth. A similar hidden channel, buried just below the surface of the ground, leads from the southern exit eastwards to the town of Pythagoreion.
In the mountain itself, the water used to flow in pipes in a separate channel several metres below the human access channel, connected to it by shafts or by a trench.
The southern half of the tunnel was dug to larger dimensions than the northern half, which in places is just wide enough for one person to squeeze through and has a pointed roof of stone slabs to prevent rockfalls. The southern half, by contrast, benefits from being dug through a more stable rock stratum.
The north and south halves of the tunnel meet in the middle of the mountain at a dog-leg, a technique to assure they did not miss each other. (This method is documented by Hermann J. Kienast and other researchers.) In planning the dig, Eupalinos used now well-known principles of geometry, codified by Euclid several centuries later. With a length of 1,036 metres (3,399 ft), the Eupalinian subterranean aqueduct is famous today as one of the masterpieces of ancient engineering. Eupalinos was aware that errors in measurement and staking could make him miss the meeting point of the two teams, either horizontally or vertically. He therefore employed the following techniques.
The tunnel has a width of approximately 1.8 by 1.8 metres (5.9 by 5.9 ft). Eupalinos calculated the expected position of the meeting point in the mountain. Knowing that two parallel lines never meet, Eupalinos recognized that an error of more than two metres (6.6 ft) horizontally meant that the north and south tunnels would never meet. Therefore, he changed the direction of both tunnels, as shown in the picture (one to the left and the other to the right), so that a crossing point would be guaranteed, even if the tunnels were previously parallel and far away.
Similarly, there was also a possibility of vertical deviations and, again, Eupalinos could not take a chance. He increased the possibility of the two tunnels meeting each other, by increasing the height of both tunnels. In the north tunnel he kept the floor horizontal and increased the height of the roof, while in the south tunnel he kept the roof horizontal and increased the height by changing the level of the floor. His precautions as to vertical deviation proved unnecessary, however, since measurements show that there was very little error; Kienast reports a vertical difference in the opening of the tunnels of only four centimetres (1.6 in).
Recent research has shown that Eupalinos actually used three straight lines for his navigation. First he constructed a “mountain” line, over the mountain at the easiest part of the summit which gave a non-optimal position both for feeding water into the tunnel and for water delivery to the city. He connected a “south line” to the mountain line at the south side going straight into the mountain around which Eupalinos undulated the south tunnel. At the north side a “north line” is connected to the mountain line. This line guided the cut into the mountain from the north side. After 273 meters Eupalinos directed the tunnel to the west, obviously because of a combination of water, weak rock and mud. When leaving the north line Eupalinos used for navigating an isosceles triangle with angles 22.5, 45 and 22.5 degrees in theory. Measuring errors occurred and were handled by Eupalinos within the accuracy he could obtain. The cutting of the south tunnel was stopped after 390 metres for the north tunnel to catch up. For the rendezvous of the two tunnels a tentacle was applied at the head of the south tunnel, giving 17 metres wider catching width. When the two tunnels reach within earshot, which can be estimated for this type of rock to approximate 12 metres, the tunnels are directed towards each other and meet at a nearly right angle. This took place almost under the summit, but that was coincidental. Eupalinos levelled around the mountain probably following a contour line but not necessary at the same level as the tunnel. He underestimated his measuring accuracy because, before the rendezvous, he raised the ceiling of the north tunnel by 2.5 m and lowered the floor of the south tunnel by 0.6 m, giving him a catching height of almost 5 metres. At the rendezvous, the closing error in altitude for the two tunnels was a few decimetres. Eupalinos used a unit of 20.59 metres for distance measurements and 7.5 degrees (1/12 of a right angle) for setting out directions.
Ancient Greek in classical antiquity, before the development of the common Koine Greek of the Hellenistic period, was divided into several varieties.
Most of these varieties are known only from inscriptions, but a few of them, principally Aeolic, Doric, and Ionic, are also represented in the literary canon alongside the dominant Attic form of literary Greek.
Likewise, Modern Greek is divided into several dialects, most derived from Koine Greek.Construction surveying
Construction surveying or building surveying (otherwise known as "staking", "stake-out", "lay-out", "setting-out" or "BS") is to stake out reference points and markers that will guide the construction of new structures such as roads or buildings. These markers are usually staked out according to a suitable coordinate system selected for the project.Cycladic culture
Cycladic culture (also known as Cycladic civilisation or, chronologically, as Cycladic chronology) was a Bronze Age culture (c. 3200–c. 1050 BC) found throughout the islands of the Cyclades in the Aegean Sea. In chronological terms, it is a relative dating system for artefacts which broadly complements Helladic chronology (mainland Greece) and Minoan chronology (Crete) during the same period of time.Demonax
Demonax (Greek: Δημώναξ, Dēmōnax, gen.: Δημώνακτος; c. AD 70 – c. 170) was a Greek Cynic philosopher. Born in Cyprus, he moved to Athens, where his wisdom, and his skill in solving disputes, earned him the admiration of the citizens. He taught Lucian, who wrote a Life of Demonax in praise of his teacher. When he died he received a magnificent public funeral.Eupalinos
Eupalinos (Ancient Greek: Εὐπαλῖνος) or Eupalinus of Megara was an ancient Greek engineer who built the Tunnel of Eupalinos on Samos Island in the 6th century BC.
The tunnel, presumably completed between 550 and 530 BC, is the second known tunnel in history which was excavated from both ends and the first with a methodical approach in doing so. Being also the longest tunnel of its time, the Tunnel of Eupalinos is regarded as a major feat of ancient engineering. It was constructed for the tyrant Polycrates of Samos, and was a remarkable 1,036 meters (3,399 ft) long. It brought water to the city, passing through limestone at the base of a hill; this tunnel still exists.
The Greek historian Herodotus describes the tunnel briefly in his Histories (3.60) and calls Eupalinos of Megara its architect:
I have dwelt rather long on the history of the Samians because theirs are the three greatest works (ergasmata) of all the Greeks. One is a tunnel (orygma amphistomon) through the base of a nine hundred foot high mountain. The tunnel's length is seven stades, its height and length (width) both eight feet. Throughout its length another cutting (orygma) has been dug (ororyktai) three feet wide and three feet deep, through which the water flowing in pipes is led into the city from an abundant spring. The builder (architekton) of the tunnel was the Megarian Eupalinus, son of Naustrophus.
Eupalinos is considered the first hydraulic engineer in history whose name has been passed down. Apart from that, though, nothing more is known about him.A large road tunnel, named after Eupalinos has been recently built under the Geraneia mountains in Corinthia, to facilitate the new expressway connection between Athens and Corinth. Eupalinos tunnel is the longest of three subsequent tunnels of the same width at this expressway.Greece in the Roman era
Greece in the Roman era describes the period of Greek history when Ancient Greece was dominated by the Roman Republic (509 – 27 BC), the Roman Empire (27 BC – AD 395), and the Byzantine Empire (AD 395 – 1453). The Roman era of Greek history began with the Corinthian defeat in the Battle of Corinth in 146 BC. However, before the Achaean War, the Roman Republic had been steadily gaining control of mainland Greece by defeating the Kingdom of Macedon in a series of conflicts known as the Macedonian Wars. The Fourth Macedonian War ended at the Battle of Pydna in 148 BC and defeat of the Macedonian royal pretender Andriscus.
The definitive Roman occupation of the Greek world was established after the Battle of Actium (31 BC), in which Augustus defeated Cleopatra VII, the Greek Ptolemaic queen of Egypt, and the Roman general Mark Antony, and afterwards conquered Alexandria (32 BC), the last great city of Hellenistic Greece. The Roman era of Greek history continued with Emperor Constantine the Great's adoption of Byzantium as Nova Roma, the capital city of the Roman Empire; in AD 330, the city was renamed Constantinople; afterwards, the Byzantine Empire was a generally Greek-speaking polity.Grotta-Pelos culture
The Grotta-Pelos culture (Greek: Γρόττα-Πηλός) refers to a "cultural" dating system used for part of the early Bronze Age in Greece. Specifically, it is the period that marks the beginning of the so-called Cycladic culture and spans the Neolithic period in the late 4th millennium BC (ca. 3300 BC), continuing in the Bronze Age to about 2700 BC.
The term was coined by Colin Renfrew, who named it after the sites of Grotta and Pelos on the Cycladic islands of Naxos and Milos, respectively. Other archaeologists prefer a "chronological" dating system and refer to this period as the Early Cycladic I (ECI).Hydraulic engineering
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.
Hydraulic engineering is the application of the principles of fluid mechanics to problems dealing with the collection, storage, control, transport, regulation, measurement, and use of water. Before beginning a hydraulic engineering project, one must figure out how much water is involved. The hydraulic engineer is concerned with the transport of sediment by the river, the interaction of the water with its alluvial boundary, and the occurrence of scour and deposition. "The hydraulic engineer actually develops conceptual designs for the various features which interact with water such as spillways and outlet works for dams, culverts for highways, canals and related structures for irrigation projects, and cooling-water facilities for thermal power plants."Hydraulics
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and cover concepts such as pipe flow, dam design, fluidics and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the vascular system and erectile tissue.
Free surface hydraulics is the branch of hydraulics dealing with free surface flow, such as occurring in rivers, canals, lakes, estuaries and seas. Its sub-field open-channel flow studies the flow in open channels.
The word "hydraulics" originates from the Greek word ὑδραυλικός (hydraulikos) which in turn originates from ὕδωρ (hydor, Greek for water) and αὐλός (aulos, meaning pipe).Kastelli Hill
Kastelli Hill (also Kasteli; Greek: Λόφος Καστέλλι or Καστέλι) is a landform at the city of Chania on the island of Crete in the present day country of Greece. The Minoan city of ancient Cydonia was centered on Kastelli Hill, which later was selected by the Romans as the site of an acropolis.Megara
Megara (; Greek: Μέγαρα, pronounced [ˈmeɣara]) is a historic town and a municipality in West Attica, Greece. It lies in the northern section of the Isthmus of Corinth opposite the island of Salamis, which belonged to Megara in archaic times, before being taken by Athens. Megara was one of the four districts of Attica, embodied in the four mythic sons of King Pandion II, of whom Nisos was the ruler of Megara. Megara was also a trade port, its people using their ships and wealth as a way to gain leverage on armies of neighboring poleis. Megara specialized in the exportation of wool and other animal products including livestock such as horses. It possessed two harbors, Pegae, to the west on the Corinthian Gulf and Nisaea, to the east on the Saronic Gulf of the Aegean Sea.Paideia
In the culture of ancient Greece, the term paideia (also spelled paedeia) (; Greek: παιδεία, paideía) referred to the rearing and education of the ideal member of the polis. It incorporated both practical, subject-based schooling and a focus upon the socialization of individuals within the aristocratic order of the polis. The practical aspects of this education included subjects subsumed under the modern designation of the liberal arts (rhetoric, grammar, and philosophy are examples), as well as scientific disciplines like arithmetic and medicine. An ideal and successful member of the polis would possess intellectual, moral and physical refinement, so training in gymnastics and wrestling was valued for its effect on the body alongside the moral education which the Greeks believed was imparted by the study of music, poetry, and philosophy. This approach to the rearing of a well-rounded Greek male was common to the Greek-speaking world, with the exception of Sparta where a rigid and militaristic form of education known as the agoge was practiced.Phylakopi I culture
The Phylakopi I culture (Greek: Φυλακωπή) refers to a "cultural" dating system used for the Cycladic culture that flourished during the early Bronze Age in Greece. It spans the period ca. 2300-2000 BC and was named by Colin Renfrew, after the settlement of Phylakopi on the Cycladic island of Milos. Other archaeologists describe this period as the Early Cycladic III (ECIII).Polycrates
Polycrates (; Greek: Πολυκράτης, in English usually Polycrates but sometimes Polykrates), son of Aeaces, was the tyrant of Samos from c. 538 BC to 522 BC. He had a reputation as both a fierce warrior and an enlightened tyrant.Pythagoreio
Pythagoreio (Greek: Πυθαγόρειο) is a small town and former municipality on the island of Samos, North Aegean, Greece. Since the 2011 local government reform, it is part of the municipality Samos, of which it is a municipal unit. Population 7,996 (2011). It is the largest municipal unit in land area on Samos, at 164.662 km2 (63.576 sq mi). It shares the island with the municipal units of Vathy, Karlovasi, and Marathokampos. The archaeological remains in the town, known collectively as Pythagoreion, has designated a joint UNESCO World Heritage Site with nearby Heraion.The seat of the municipality was the town of Pythagorio, formerly known as Tigani. The town was renamed in 1955 to honour the locally born mathematician and philosopher Pythagoras. The port of the town is considered to be the oldest man-made port of the Mediterranean Sea.Pythagoreion
The Pythagoreion is the archaeological site of the ancient town of Samos in Samos, Greece. It is located in the area of the modern town of Pythagoreio, from which it has got its modern name.
The archaeological site contains ancient Greek and Roman monuments and a famous ancient tunnel, the Tunnel of Eupalinos or Eupalinian aqueduct. Along with the Heraion of Samos, the Pythagoreion was registered as a UNESCO World Heritage Site in 1992.Samos Prefecture
Samos Prefecture (Greek: Νομός Σάμου) was a prefecture in Greece, consisting of the islands of Samos, Ikaria and the smaller islands of Fournoi Korseon. In 2011 the prefecture was abolished and the territory is now covered by the regional units of Samos and Ikaria. Its capital was the town of Vathy, on Samos.