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Vesuvius, Italy Location: 40.8N, 14.4E Elevation: 4,200 feet (1,281 m)

Vesuvius, Space Shuttle photograph. Compare to the map below. The Somma Rim, a caldera-like structure formed by the collapse of a stratovolcano about 17,000 years ago, is visible as an arcuate dark area to the right and above Vesuvius. The Bay of Naples is on the lower left. The small hook of land near the right margin of the photo is part of a caldera of the Phlegraean Fields volcanic region. The caldera formed about 34,000 years ago. From 1983-1985 an area of 31 square miles (80 square kilometers) was uplifted, in places up to 5.9 feet (1.8 meters), damaging homes, the harbor, and the tourist industry. Ultimately 36,000 people were relocated.



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Vesuvius is famous for the catastrophic eruption in 79 A.D. that buried the towns of Herculaneum and Pompeii. Photograph is looking northwest from Pompeii to Vesuvius. Photo by Chuck Wood.

Vesuvius is a complex volcano. According to Peter Francis (p. 351) a complex volcano is "an extensive assemblage of spatially, temporally, and genetically related major and minor [volcanic] centers with their associated lava flows and pyroclastic flows." Vesuvius has a long history. The oldest dated rock from the volcano is about 300,000 years old. It was collected from a well drilled near the volcano and was probably part of the Somma volcano. After Somma collapsed about 17,000 years ago, Vesuvius began to form. Vesuvius is a stratovolcano. This vertical aerial photograph shows Vesuvius (bottom), the steep caldera wall of Somma (middle), dark lava flows from the 1944 eruption (north of Vesuvius, against the wall of Somma), and the slope of the former Somma volcano (top). U.S. Navy photograph from Green and Short (1971).



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In 5960 B.C. and 3580 B.C., Vesuvius had two eruptions that rate among the largest known in Europe. The area was frequently jolted by large earthquakes. This decorative stonework records the damage caused by an earlier earthquake, perhaps the earthquake of 62 A.D. that preceded the 79 A.D. eruption. Copyrighted photograph of Robert Decker.

The 79 A.D. eruption of Vesuvius was the first volcanic eruption ever to be described in detail. From 18 miles (30 km) west of the volcano, Pliny the Younger, witnessed the eruption and later recorded his observations in two letters. He described the earthquakes before the eruption, the eruption column, air fall, the effects of the eruption on people, pyroclastic flows, and even tsunami. Volcanologists now use the term "plinian" to refer to sustained explosive eruptions which generate high-altitude eruption columns and blanket large areas with ash. It is estimated that at times during the eruption the column of ash was 20 miles (32 km) tall. About 1 cubic mile (4 cubic kilometers) of ash was erupted in about 19 hours. Volcanoes byPeter Francis contains several direct passages from Pliny the Younger and describes the archeology of Pompeii and Herculaneum. Copyrighted photograph of a street in Pompeii by Robert Decker, 1971. Vesuvius is in the background.



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About 10 feet (3 m) of tephra fell on Pompeii, burying everything except the roofs of some buildings. The city was abandoned and its location forgotten. In 1595, excavations discovered artifacts at Pompeii and centuries of pillaging followed. Archeological excavations began in the mid-nineteenth century. Now, much of Pompeii has been excavated and it has revealed much about how people lived during that time (and died during the eruption). There are numerous molds of people in their final moments. The mold of a dog is shown in the above photo. The poor animal was chained to a post and struggled for hours before finally succumbing to the ash.

Herculaneum was buried under 75 feet (23 m) of ash deposited by a pyroclastic flow. This photo shows buildings that were near the waterfront. Photograph copyrighted and provided by Steve O'Meara of Volcano Watch International.



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Herculaneum, once a seaside resort, is now surrounded by the modern city of Ercolano. About 5,000 people lived in the city at the time of the eruption. Photograph copyrighted and provided by Steve O'Meara of Volcano Watch International.

Click here to see older drawings of Vesuvius.

Vesuvius has erupted about three dozen times since 79 A.D., most recently from 1913-1944. The 1913-1944 eruption is thought to be the end of an eruptive cycle that began in 1631. Photo by Italian Air Force from Green and Short (1971).

Click here to see postcards that show early episodes of the 1913-1944 eruption.



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The rocks at Vesuvius are called tephrite. A tephrite is basaltic in character and contains the following minerals: calcic plagioclase, augite, and nepheline or leucite.

Vesuvius is a dangerous and deadly volcano. Mudflows and lava flows from the eruption in 1631 killed 3,500 people. About 3,360 people died in the 79 A.D. eruption from ash flows and falls. Studies of past eruptions and their deposits continue. These studies help volcanologists understand the hazards associated with future eruptions. The population density in some areas of high risk is 20,000 to 30,000 per square km. About 3 million people could be seriously affected by future eruptions. In the first 15 minutes of a medium- to large-scale eruption an area with a 4 mile (7 km) radius of the volcano could be destroyed (Dobran and others, 1994). About 1 million people live and work in this area.

There are no signs of volcanic unrest at Vesuvius at the present time (February 1996).

Vesuvius is above a subduction zone. The African plate is moving northward at about one inch (2-3 cm) per year and is slowly closing the Mediterranean basin. As it moves to the north, the African plate is pushed beneath the Eurasian plate.

Additional photos of Vesuvius

More information is available on the Vesuvius Wikipedia page.

For live webcam images of Vesuvius, click here.

Sources of Information:

Bowersock, G.S., 1980, The rediscovery of Herculaneum and Pompeii: The American Scholar, v. 49, p. 461-470.

Carey, S., and Sigurdsson, H., 1987, Temporal variations in column height and magma discharge rate during the 79 A.D. eruption of Vesuvius: Geological Society of America Bulletin, v. 99, p. 303-314.



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D'arms, J., 1970, Romans on the Bay of Naples: Cambridge, Massachusetts, Harvard University Press.

Dobran, F., Nerl, A., and Tedesco, M., 1994, Assessing the pyroclastic flow hazard at Vesuvius: Nature, v. 367, p. 551-554.

Etienne, R., 1992, Pompeii The Day the City Died: New York, Thames and Hudson, 216 p.

Francis, P., 1994, Volcanoes a planetary perspective: Oxford University Press, New York, 443 p.

Green, J., and Short, N.M., 1971, Volcanic landforms and surface features: New York, Springer-Verlag, 519 p.

Imbo, G., 1965, Italy. Catalog of Active Volcanoes of the World, Rome: IAVCEI, 18, 72 p.

Maiuri, A., 1958, Pompeii: Scientific American, v. 198, p. 68-78.

Radice, B., 1968, The Letters of Younger Pliny: New York, Penguin.

Rosi, M., Santacrose, R., and Sheridan, M.F., 1981, Volcanic hazards of Vesuvius (Italy): Bulletin du Bureau des Recherches Geologiques et Minieres, 4, p. 169-179.

Sheridan, M.F., Barberi, F., Rosi, M., and Santacrose, R., 1981, A model for Plinian eruptions of Vesuvius: Nature, v. 289, p. 282-285.

Sigurdsson, H., Carey, S., Cornell, W., and Pescatore, T., 1985, The eruption of Vesuvius in A.D. 79: National Geographic Research, v. 1, no. 3, p. 332-387.

Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.

Images of Volcanoes To VolcanoWorld



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You can help give the gift of knowledge by donating to Wikipedia!

Tax-deductibility of donations - Daily report

Colosseum From Wikipedia, the free encyclopedia. Jump to: navigation, search

For other uses, see Colosseum (disambiguation). See also the band Colosseum.

The Colosseum in Rome, Italy: an exterior view of the best-preserved section.

The Colosseum or Coliseum, originally known as the Flavian Amphitheatre (lat.Amphitheatrum Flavium), is an amphitheatre in Rome, capable of seating 50,000 spectators, which was once used for gladiatorial combat. Construction was initiated by Emperor Vespasian and completed by his sons, Titus and Domitian, between AD 72 and AD 81. It was built at the site of Nero's enormous palace, the Domus Aurea. The Colosseum's name is derived from a colossus (a 130-foot, or 40-metre, statue) of Nero which once stood nearby. The Colosseum is located at 41.53° N 12.293° E.

Contents [hide]

1 Construction 2 Games 3 History of the name Colosseum4 Description 5 Later history 6 Hollywood and the Colosseum 7 Flora 8 See also 9 External links

[edit]



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Construction

An interior of the Colosseum. The floor is modern reconstruction; below are the underground vaults and tunnels originally used to house animals and slaves.

The construction of the Colosseum began under the rule of Emperor Vespasian in AD 72 and was completed by his son, Titus, in the 80s AD. It was built at the site of Nero's enormous palace, the Domus Aurea, which had been built after the great fire of Rome in AD 64. Some historians believe that the construction of the Colosseum might have been financed by the looting of King Herod the Great's Temple in Jerusalem which occurred about AD 70. Dio Cassius said that 9,000 wild animals were killed in the one hundred days of celebration which inaugurated the amphitheatre opening. The arena floor was covered with sand, presumably to allow the blood to drain away.

[edit] Games

The Colosseum hosted large-scale spectacular games that included fights between animals (venationes), the killing of prisoners by animals (see: Zoophilia: Roman games and circus)and other executions (noxii), naval battles (naumachiae, via flooding the arena) up until AD 81, and combats between gladiators (munera). It has been estimated that several hundreds of thousands died in the Colosseum games. Saint Ignatius of Antioch was martyred there.

[edit] History of the name Colosseum

The Colosseum's name is derived from a colossus (a 130-foot or 40-metre statue) of Nero nearby. This statue was later remodeled by Nero's successors into the likeness of Sol, the sun god, by adding the appropriate solar crown. Nero's head was also replaced several times by the head of succeeding emperors. At some time during the Middle Ages, the statue disappeared; experts suspect that, since the statue was bronze, it was melted down for reuse.

After the colossus' disposal, the link to it seems to have been forgotten over time, and the name was corrupted to Coliseum in the Middle Ages. Both names are frequently used in modern English, but Flavian Amphitheatre is generally unknown. In Italy, it is still known as ilcolosseo, but other Romance languages have come to use forms such as le colisée and elcoliseo.

[edit]



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Description

The inner layers of the Colosseum, showing the construction of the outer layers.

The Colosseum measures 48 metres high, 188 metres long, and 156 metres wide. The wooden arena floor was 86 metres by 54 metres, and covered by sand. Its elliptical shape kept the players from retreating to a corner, and allowed the spectators to be closer to the action than a circle would allow.

The Colosseum was ingeniously designed. It has been said that most spectacle venues (stadiums, and similar) have been influenced by features of the Colosseum's structure, even well into modern times. Seating (cavea) was divided into different sections. The podium, the first level of seating, was for the Roman senators; the emperor's private, cushioned, marble box was also located on this level. Above the podium was the maenianum primum, for the other Roman aristocrats who were not in the senate. The third level, the maenianum secundum, was divided into three sections. The lower part (the immum) was for wealthy citizens, while the upper part (the summum) was for poor citizens. A third, wooden section (the maenianum secundum in legneis) was a wooden structure at the very top of the building, added by Domitian. It was standing room only, and was for lower-class women.

A small section of the spectators' walkway inside the Colosseum.

After the Colosseum's first two years in operation, Vespasian's younger son (the newly-designated Emperor Domitian) ordered the construction of the hypogeum (literally meaning "underground"), a two-level subterranean network of tunnels and cages where gladiators and animals were held before contests began. Numerous trap doors in the floor provided instant access to the arena for caged animals and scenery pieces concealed underneath; larger hinged platforms, called hegmata, provided access for elephants and the like.

Today the arena floor no longer exists, though the hypogeum walls and corridors are clearly visible in the ruins of the structure. The entire base of the Colosseum covers an area equivalent to 6 acres (24,200 m²). There are also tunnels, still in existence, configured to flood and evacuate water from the Colosseum floor, so that naval battles could be staged prior to the hypogeum's construction. Recent archaeological research has shown evidence of



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drain pipes connected to the City's sewer system and a large underground holding tank connected to a nearby aqueduct.

A map of central Rome during the Roman Empire, with Amphitheatrum Flavium at the upper right corner.

Another innovative feature of the Colosseum was its cooling system, known as the valerium,which consisted of a canvas-covered, net-like structure made of ropes, with a hole in the center. This roof covered two-thirds of the arena, and sloped down towards the center to catch the wind and provide a breeze for the audience. Sailors, standing on special platforms, manipulated the ropes on command. The Colosseum incorporated a number of vomitoria — passageways that open into a tier of seats from below or behind. The vomitoria were designed so that the immense venue could fill in 15 minutes, and be evacuated in as little as 5 minutes. Each entrance and exit was numbered, as was each staircase.

There were 80 entrances at ground level, 76 for ordinary spectators, two for the imperial family, and two for the gladiators. Spectators were given tickets in the form of numbered pottery shards, which directed them to the appropriate section. The vomitoria quickly dispersed people into their seats and, upon conclusion of the event, disgorged them with abruptness into the surrounding streets (giving rise, presumably, to the name).

[edit] Later history

The Colosseum was in continuous use until 217, when it was damaged by fire after it was struck by lightning. It was restored in 238 and gladiatorial games continued until Christianitygradually put an end to those parts of them which included the death of humans. The building was used for various purposes, mostly venationes (animal hunts), until 524. Two earthquakes (in 442 and 508) caused a great damage to the structure. In the Middle Ages, it was severely damaged by further earthquakes (847 and 1349), and was then converted into a fortress.

The marble that originally covered the façade was burned to make quicklime. During the Renaissance, but mostly in the Baroque age, the ruling Roman families (from which many popes came) used it as a source of marble for the construction of St. Peter's Basilica and the private Palazzi. A famous description is in the saying Quod non fecerunt Barbari, fecerunt Barberini; "What the Barbarians weren't able to do, was done by the Barberinis" (one such family).

The Venerable Bede (c. 672–735) wrote:[1]

Quandiu stabit coliseus, stabit et Roma (As long as the Colosseum stands, so shall Rome);Quando cadit coliseus, cadet et Roma (When the Colosseum falls, so shall Rome); Quando cadet Roma, cadet et mundus (When Rome falls, so shall the world).



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Note the use of coliseus, i.e. which made the name a masculine noun. This form is no longer in use.

A view of the Colosseum at night.

In 1749, in a very early example of historic preservation, Pope Benedict XIV forbade the use of the Colosseum as a quarry. He consecrated the building to the Passion of Christ and installed Stations of the Cross, declaring it sanctified by the blood of the Christian martyrswho were thought to have perished there. Later popes initiated various stabilization and restoration projects. Every Good Friday the pope leads a procession within the ellipse in memory of Christian martyrs.[2]. It is presumed that the majority of Christian martyrdom in Rome took place at the Circus Maximus.

In 2000 there was a diffused protest in Italy against the death penalty all over the world (in Italy it was abolished in 1948); several manifestations took place in front of the Colosseum. The illumination of the Colosseum is always on, and so it was at that time, but in that period, as a gesture against capital punishment, the local authorities of Rome changed the colour of the night time illumination from white to gold whenever a person condemned to the deathpenalty anywhere in the world gets commuted or released. [3]

According to the current political division of the center of Rome, the Colosseum is placed in rione Monti.

[edit] Hollywood and the Colosseum

The Colosseum has a prominent place in many motion pictures. In 1954's Demetrius and the Gladiators Emperor Caligula sentences the Christian Demetrius to fight in the Colosseum's gladiator games. In the Science Fiction film The Core, the Colosseum is destroyed by intense lightning strikes, which blast it to bits. In director Ridley Scott's 2000 film Gladiator, the Colosseum was re-created via computer-generated imagery (CGI) to "restore" it to the glory of its heyday in the 2nd century. However, many of the buildings depicted surrounding the colosseum never existed.

[edit] Flora



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Plants on the inner walls of the Colosseum

The Colosseum has a wide and well-documented history on the flora that grows in the amphitheatre. From 1643 on, when doctor Domenico Panaroli started to make a list of all plants in the Colosseum, there has been a total of 684 species. The peak was in 1855 (420 species), which decreased to 242 today. 200 of the species were present from the time that the first list was compiled through now.

The variety of different kinds of plants can be explained by the change of climate in Rome throughout the centuries. Bird migration, flower blooming, the growth of Rome that caused the Colosseum to not be on the outside skirts of the city anymore and deliberate transport of species are other ways to clearify the wide stream of plants.

[edit] See also

Ancient world List of buildings Wikitravel article

[edit] External links

Wikimedia Commons has media related to: Colosseum

Google Maps satellite view of Colosseum

For broadband: Interactive high quality fullscreen QTVR panoramas

also available for low bandwidth in java: http://rome.arounder.com/colosseo/java.html

The Colosseum on the interactive map of Rome by Activitaly The Roman Colosseum, Rome virtual reality movies and pictures The COLOSSEUM � a site on the Roman amphitheatre A cut away view showing internal construction Colosseum's Flora

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The Pantheon-- Rome -126 ADA temple to all gods - by Freda Parker

Michelangelo (1475-1564) looked at everything with an artist's critical eye, and he was not easily impressed. But when Michelangelo first saw the Pantheon in the early 1500s, he proclaimed it of "angelic and not human design." Surprisingly, at that point, this classic Roman temple, converted into a Christian church, was already more than 1350 years old.

What's even more surprising is that the Pantheon, in the splendor Michelangelo admired, still stands today - another 500 years after he saw it.

In truth, no one knows the Pantheon's exact age. One legend says that the first Roman citizens built the original Pantheon on the very site where the current one still stands in the Campo Marzo - modern Rome's business district. The ancients constructed this first Pantheon after Romulus (753-716 BC), their mythological founder, ascended to heaven from that site. They dedicated it to Romulus and some of his divine ancestors and, for centuries, held rites and processions there.

Most historians, however, claim that Emperor Marcus Vipsanius Agrippa built the first Pantheon in 27 BC, a rectilinear, T-shaped structure, 144 feet by 66 feet (44m x 20m), with masonry walls and a pitched timber roof. It burned in the great fire of 80 AD, was rebuilt by Emperor Domitian, but was struck by lightening and burned again in 110 AD.

Seven years later, Hadrian, the adopted son and successor of Emperor Trajan, became Rome's ruler. Hadrian was elegance personified. He was tall and strong, had his hair curled and his full beard groomed daily.Moreover, Hadrian saw himself as a divinely inspired poet, with an avid interest in Hellenic culture, especially literature, music and architecture - so much so that his contemporaries snidely

called him "the Greekling."

By 120 AD, Hadrian began designing a Pantheon reminiscent of Greek temples and far more elaborate than anything Rome had yet seen. His plans called for a structure with three main parts: a pronaos or entrance portico, a circular domed rotunda or vault, and a connection between the two. The rotunda's internal geometry would create a perfect sphere, since the height of the rotunda to the top of its dome would match its diameter: 142 feet (43.30 m). At its top, the dome would have an oculus or eye, a circular opening, with a diameter of 27 feet (8.2m), as its only light source.

Hadrian said, "My intentions had been that this sanctuary of All Gods should reproduce the likeness of the terrestrial globe and of the stellar sphere...The cupola...revealed the sky through a great hole at the center, showing alternately dark and blue. This temple, both open and mysteriously enclosed, was conceived as a solar quadrant. The hours would make their round on that caissoned ceiling so carefully polished by Greek artisans; the disk of daylight would rest suspended there like a shield of gold; rain would form its clear pool on the pavement below, prayers would rise like smoke toward that void where we

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place the gods."

Hadrian visualized himself enthroned directly under the Pantheon's oculus - a near-deity around whom not only the Roman empire but the universe, the

sun, and the heavens obediently revolved.

Hadrian's engineers began clearing the site and preparing the foundations. They dug a circular trench 26 feet (8 m) wide and 15 feet (4.5 m) deep for the rotunda's foundation and rectangular trenches for the pronaos and the connector. They lined the trenches with timber forms and layered those with pozzolana cement - a powerful cement that the Romans discovered they could make by grinding together

lime and a volcanic product found at Pozzuoli, Italy.

Though the Romans had been building with concrete since about 200 BC, work on the Pantheon was difficult and proceeded in gradual stages. Other buildings surrounded the site so laborers lacked space in which to work.

They also lacked machinery. Vitruvius (cir. 20 BC), a noted Roman architect, recorded the process followed in his day, that was probably still used by the Pantheon's builders. The ancients hand mixed wet lime and volcanic ash in a mortar box, adding very little water so that they got a nearly dry composition. They carried this mixture to the job site in baskets and poured itover a prepared layer of rock pieces. They then tamped the mortar into the rock layer. The tamping packed the mortar, reduced the need for excess water, but, at the same time, stimulated bonding.

Transportation presented another problem. Just about everything had to come down the Tiber by boat, including the 16 gray granite columns Hadrian ordered for the Pantheon's pronaos. Each was 39 feet (11.8 m) tall, five feet (1.5 m) in diameter, and 60 tons in weight. Hadrian had these columns quarried at Mons Claudianus in Egypt's eastern mountains, dragged on wooden sledges to the Nile, floated by barge to Alexandria, and put on vessels for a trip across the Mediterranean to the Roman port of Ostia. From there the columns were barged up the Tiber.

Eventually, work began on the concrete dome, constructed in tapering courses or steps that are thickest at the base (20 feet) and thinnest at the oculus (7.5 feet). The Romans used the heaviest aggregate, mostly basalt, at the bottom and lighter materials, such as pumice, at the top.

They embedded empty clay jugs into the dome's upper courses to further lighten the structure and facilitate the concrete's curing.

In the dome's construction, the Romans probably used temporary wooden centering on which they layered concentric rings of masonry and concrete.

Through the ages, engineers have theorized about the centering. Some say the Romans used heavy wooden

scaffolding, throughout the construction process, that reached from the floor to the oculus.

Others believe that centering was not required for the lower third of the

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dome, so the Romans used a lighter centering system supported from the dome's interior, second cornice line.

To create the dome's oculus, which acts as a compression ring, the Romans built two circles of bipedales, handmade bricks that were 23.4 inches (60 cm) square and 1.56 inches (4 cm) thick. They laid the bipedales edgewise in three vertical courses, then circled the oculus with a bronze cornice.

The oculus was not the only feature that got a bronze treatment. Hadrian had the original roof bronze-tiled and the Latin lettering on the entablature inscribed in bronze. It read: M AGRIPPA L F COS TERTIUM FECIT, which translates to "Built by Marcus Agrippa, the son of Lucius, third counsul."

Why the egotistical Hadrian insisted on crediting his predecessor for the Pantheon remains an unsolved mystery. Some believe he did it as a symbolic gesture that reinforced his connection to Rome's ancient imperial line. But thePantheon presents yet another, far greater mystery. Why, after nearly 2000 years, is this structure, built on marshy land, with a dome whose span was not surpassed for hundreds of years, still standing?

Theories abound. Some believe the Pantheon is divinely protected. Until the 5th century, it was a temple dedicated to all the Roman gods. In 609, Emperor Phocas gave it to Pope Boniface IV, who consecrated it, dedicated it to St. Mary and all the Christian martyrs, and renamed it Santa Maria ad Martyres.

While the Pantheon may be divinely protected, there are more earthbound reasons for its survival as well. It was built of a very strong concrete with pozzolona cement. A gradation process was used so that the structure is heavier at the bottom and much lighter at the top. The dome's oculus or opening lightens the load and acts as a compression ring.

Whatever the reasons, the Pantheon is the only structure of its age, size and span that has successfully survived the scourge of time and gravity and has come down to us, intact, and in all its splendor and beauty. Like Michelangelo, we too can look at the Pantheon and marvel at this wonder that looks more like the work of angels, not men.

Reference Sources:http://www.romanconcrete.com/http://www.greatbuildings.com/http://www.chch.school.nz/mbc/panth1.htmhttp://www-viz.tamu.edu/http://www.romeguide.it/MONUM/ARCHEOL/pantheon/http://ross.pvt.k12.ny.us/Rome/Pantheon/http://www.sc.whecn.edu/http://archserve.id.ucsh.edu/AH152K/concrete.htmhttp://harpy.uccs.edu/roman/html/hadrian2.htmlhttp://www.wegm.com/

THE PANTHEON

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http://www.romanconcrete.com/

http://www.greatbuildings.com/

http://www.chch.school.nz/mbc/panth1.htm

http://www-viz.tamu.edu/

http://www.romeguide.it/MONUM/ARCHEOL/pantheon/

http://ross.pvt.k12.ny.us/Rome/Pantheon/

http://www.sc.whecn.edu/

http://archserve.id.ucsh.edu/AH152K/concrete.htm

http://harpy.uccs.edu/roman/html/hadrian2.html

http://www.wegm.com/

Built: 120-126 AD under Emperor Hadrian Foundation: 24' thick at base and steps to 21' at ground level Rotunda: concrete, 20' thick; 142' diameter Oculus: concrete: 7.5' thick;27' diameter Interior Columns: 3' diameter, 29' tall topped witha corinthian capital of 4' totalling 32' 9" tall, 25 tons each Portico: 16 granite columns 39' tall, 5' diameter, 60 tons each

The Monolithic Dome And The PantheonMonolithic's President David South says that in building Monolithic Domes wehave three major advantages the Pantheon's builders simply did not have:

1. Airforming - The Romans created the Pantheon's form with earthworks and timber - an arduous, time-consuming process. We can inflate a giant Airform in less than two hours. The Airform has theadditional advantages of being portable and ultimately becoming the roof membrane of the finished structure.

2. Concrete - The Pantheon's concrete was a mixture of pozzolan, lime and a small amount of water. That mixture was tamped - not poured - into place. Today, we have portland cement, which is easily ten times stronger and much easier to work with.

3. Rebar - All concrete is weak in tension. We strengthen our concrete with reinforcing steel (rebar). The Romans did not have that option. They used ropes of vitreous china for reinforcement. To further compensate for the weakness and weight of the concrete, the Romans built extremely thick footing and drum walls. Otherwise, the weight of the dome would have spread the vertical walls of the drum and the Pantheon would not have lasted.



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EDDYSTONELIGHTHOUSEHISTORY

Position 50° 10’.80 N 04° 15’.90 W

Established 1703 (present tower 1882). Height of tower 51 metres. Height of light above Mean High Water 41 metres. Range 24 miles. Intensity 570,000 candle power. Light Characteristics-- White Group Flashing twice every 10 seconds. Subsidiary Fixed Red Light-- covers a 17 degree arc marking a dangerous reef called the Hands Deep. Fog Signal-- Super Tyfon sounding three times every 60 seconds. Automatic Light--Serviced via Helicopter Platform.

One of the world's most famous, if not the most famous lighthouses is the Eddystone Lighthouse, which stands on a treacherous group of rocks some fourteen miles out at sea, bearing 211° from Plymouth Breakwater, in the South West of the United Kingdom.

The Eddystone Lighthouse was the first lighthouse to be built on a small group of rocks in the open sea and resulted in a few disasters until the present lighthouse which stands there today. Given the harsh surrounding these early lighthouses where a marvel of ingenuity.

WINSTANLEY’S TOWER 1698 - 1703

The first tower attempt to render the Eddystone Reef of rocks safe to shippingwas by Henry Winstanley a merchant and we are told an eccentric. Winstanley invested money in shipping and it was one of these ships that was wrecked on the Eddystone Reef. It was then that Winstanley promised to rid the English Channel of such a menace to shipping. This first lighthouse was a marvel of early engineering.

In 1696 Winstanley commenced work on a wooden structure The work progressed steadily until 1697 when a incident occurred in which a French privateer captured Winstanley and took him to France. England was at war withFrance at this time. However, when Louis XIV heard of the incident he immediately ordered that Winstanley be released saying that "France was at



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war with England not which humanity". This proved the international importance of the Eddystone Lighthouse.

The light on the Eddystone was first lit on the 14th of November 1698, and although the lighthouse survived that first winter it was found to be badly in need of repair. The whole top of the structure was removed and a 2nd tower was then erected.

During the following spring Winstanley greatly altered and strengthened his 2nd tower whilst imparting numerous new features. The lighthouse was finally finished in 1699.

Having great confidence in his structure Winstanley expressed a wish to be on the lighthouse during a storm. In November 1703, the greatest storm ever recorded in this country occurred and Winstanley had arrived at the lighthouse the evening before to carry out urgent repairs. The following day there was hardly any of the lighthouse structure to be seen and its occupants had disappeared. The lighthouse had survived only five years.

RUDYERD’S TOWER 1709 - 1755.

The 3rd lighthouse was built by a man who managed to get a patent charter for the Eddystone Lighthouse. His name was Captain Lovett. He managed to get a lease on the Eddystone Rocks for a period of 99 years by an Act of Parliament. As a result he was allowed to charge all ships passing a toll of 1 penny per ton, both inwards and outward. Iam unsure how this was collected but it must have been interesting.

The designer of this lighthouse was John Rudyerd, who was a silk merchant. Rudyerd designed a cone shaped tower instead of Winstanley's octagonal shape. His final wooden tower was lit in 1709 and proved much more serviceable than Winstanley's Lighthouse. This lighthouse had been built by a great amateur and stood for 47 years until the nightof 2nd December 1755, when the top of the lantern caught fire.

It was reported that 94 year old Henry Hall was the keeper of the watch that night. He did his best to put out the fire by throwing water upwards from a bucket. While doing so the leaden roof melted and the molten lead ran down over him, burning him badly; his mouth was open whilst looking up and some ofthe molten lead ran down his throat. He and the other keeper battled continuously against the fire but they could do nothing as the fire was above them all the time, as it burnt downwards it gradually drove them out onto the rock. The fire was observed from the shore by a Mr. Edwards, 'a man of some fortune and more humanity'. The old account says he sent off a boat which arrived at the lighthouse at 10 a.m. after the fire had been burning for 8 hours. The sea was too rough for the boat to approach the rock so they threw ropes and dragged the keepers through the waves to the boat. The lighthouse continued to burn for 5 days and was completely destroyed.

Henry Hall died some 12 days later. Doctor Spry of Plymouth who attended him made a post mortem and found a flat oval piece of lead in his stomach which weighed 7ozs. Dr. Spry wrote an account of his findings in this case to the



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Royal Society of Fellows. The society where very skeptical, he was very annoyed at this, and for the sake of his reputation carried out experiments on dogs and fowls and proved that they could live after having molten lead poured down their throats. (The piece of lead from Hall's stomach may be seen in the Edinburgh Museum)

SMEATON’S TOWER 1759 - 1882.

After experiencing the benefit of a light on the rock for 52 years mariners were anxious to have it replaced as soon as possible. Trinity House placed a light vessel to guard the position until a permanent light could be built.

In 1756 a fourth lighthouse was built by Yorkshireman, John Smeaton, recommended by the Royal Society, travelled to Plymouth on an assignment which was to capture the imagination of the world. He had decided to construct a tower based on the shape of an English oak tree for strength but made of stone rather than wood. For such a task he needed the toughest labourers, of

which he found plenty from the Cornish tin mines, however, the problem of press ganging (abducting men to labour on ships) became a regular occurrence and to stop this Trinity House had a metal badge made for each lighthouse labourer and arranged with the Admiralty at Plymouth to exempt them from abduction.

John Smeaton needed a strong rock which he found in the local granite, but further he needed the ingenuity to devise new forms of quick setting cement, a way to make dovetail joints in stone, (this method is still used today), and to lift huge stones from ships at sea to considerable heights. He surmounted all these obstacles and succeeded in building his new Eddystone Lighthouse which as lit by 24 candles on 16th October 1759. Smeaton had become the owner of the formula for quick drying cement.

In the 1870's cracks appeared in the rock on which the lighthouse stood and it was dismantled, (120 years after it was built), and re-erected on Plymouth Hoe as a monument to the builder. Smeaton's Tower was moved stone by stone from the Eddystone rocks to its present site on Plymouth Hoe and has been Plymouth's most famous landmark ever since. The stump of Smeaton's tower still stands on the original rock to this day and can be seen in our pictures.



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DOUGLASS’S TOWER - 1882 ONWARDS

No time was wasted in building yet a 5th lighthouse on the rocks. In 1877 James Douglass, Engineer-in-Chief to Trinity House, announced the decision to rebuild the lighthouse on a more solid foundation to the south east.

By now lighthouse construction was a much more refined business largely due to the efforts of Robert Stevenson, who developed Smeaton's idea and contributed many of his own and the French scientist Fresnel who made enormous progress in the field of lighthouse illumination.

Douglass used larger stones and improved on the oak tree model with the help of Trinity House engineers and in 1882 the present

Eddystone Lighthouse was completed.

A feature of the stones in the Douglass tower was that they were dovetailed notonly to each other on all sides, but each course was dovetailed to the next, calling for great accuracy from the masons.

Its original oil powered lamps were replaced in 1956 by electrics. A helicopter deck was later constructed above the lantern in 1980 as the first part of a modernisation scheme and the station became automated and unmanned in 1982 and was commissioned in a ceremony by the Duke of Edinburgh.

Eddystone Lighthouse is now monitored and controlled from the Trinity House Operations Control Centre at Harwich in Essex.

Eddystone Eel Lures would like to thank Trinity House for all of the information gleaned on the History of the Eddystone Lighthouse

which made this account possible.

(Photographs courtesy of Rob Street "Vagabond Charters", Tony Allen "Electric Blue Fishing" & Russ Symons Photo Journalist.

Other images courtesy of the Lighthouse Trust)

Link Bar 6



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In this section: William Aspdin> Bluewater > Crossways Business Park

WILLIAM ASPDIN: THE ORIGINS OF PORTLAND CEMENT EARLY CEMENT PRODUCTION

North West Kent is the cradle of the modern cement industry, but cement is as old as building itself. The very first wattle huts needed a material to bond others which would not of themselves bind together. The first cement was wet clay, and indeed wet clay is still used as a cement in the remoter parts of the world. Five thousand years ago the Egyptians made cement by mixing burnt lime and gypsum and in some cases the stones bound together then are still firmly held today.

The Romans developed the process further and there are examples of their work in Britain today, such as the Pharos at Dover and sections of London Wall. But it was only in the eighteenth century that its properties were scientifically analysed and its use in building became more general. Important names in the development are Smeaton, who built an early Eddystone lighthouse in the 1750s and Parker, who invented 'Roman' cement, with its quick setting properties, at the end of the eighteenth century.



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PORTLAND CEMENT

The great milestone was the discovery of Portland cement. Joseph Aspdin, a Leeds bricklayer, took out a patent for his 'Portland' cement in 1824 - though he claimed he had been making it since 1811. Aspdin, whose son worked with him, in fact had little scientific or chemical knowledge and used rule-of-thumb methods.

Some of the vagueness in his patent application could also have stemmed from his desire for secrecy. He talks of using road scrapings from the neighbourhood of lime kilns and only using freshly quarried limestone if these scrapings were notavailable. Aspdin was also secretive about his manufacturing process. No-one butthe workmen were allowed into his premises and he personally took part in the loading of every kiln.

It was not clear that he entirely understood what he had discovered. For example, in his patent there is no mention of the need to burn the raw materials to the point of incipient fusion. Indeed this feature was rediscovered with some difficulty by Issac Johnson at Swanscombe in 1847. Be that as it may, Aspdin was granted a patent for "Portland cement" - so called because its colour resembled that of Portland stone.

There has been some argument over whether Joseph Aspdin can actually claim to be the inventor of Portland cement. Sixty years earlier Smeaton had called his cement 'Portland' because of its resemblance to Portland stone and Aspdin's 'Portland' cement was not really like the Portland cement used in the twentieth century.



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CEMENT PRODUCTION IN THE 19TH CENTURY

What is certain is that Joseph Aspdin's youngest son William left Wakefield, set up cement works at Rotherhithe, and met Brunel finishing his ill-fated Thames Tunnel. On one occasion when the roof collapsed Brunel dumped tons of Aspdin's cement into the river. This sealed the break in the tunnel roof and Brunel was able to pump the tunnel dry. He then rebuilt it and used Portland cement for the relining. This was probably the first major civil engineering project to use cement. Brunel was obviously aware of the qualities of Portland cement because he could easily have obtained Roman cement locally at half the price.

William teamed up with a Mr Robins and a Mr Maude and built a cement works at Northfleet Creek, Kent trading as Robins, Maude and Aspdin. Aspdin's 'Beehive' kiln, used to make the first genuine Portland Cement, can still be seen at Northfleet. The oldest surviving cement kiln in the world, it has been opened up by Blue Circle for public viewing. A batch of 'bottle' kilns from the 1840s has also survived.

In The Builder of 1848 under the title of Robins, Aspdin and Co, with a wharf at Great Scotland Yard, Whitehall and a depot at Back Grove, Liverpool they advertised:

"PORTLAND CEMENT, solely manufactured by W Aspdin, son of the patentee. This cement has been proved for upwards of twenty years in the Thames Tunnel to resist the action of water, it is stronger in its cementation qualities, harder and more durable than any other description of cement: it does not vegetate, oxydate or turn green, nor is it affected by any atmospheric influence, whatever the climate, resisting alike the actions of frost and heat. It is manufactured to set in from five to sixty minutes."

Portland cement really came to the public's notice in the late 1840s as public rivalry built up between Frost's and Aspdin's. Frost's works at Swanscombe had been bought by J Bazley White in 1834. There had been repeated failures of Roman cement, and Portland cement came to be seen as superior. Even so, by 1850 there were still only four works, producing Portland cement. After 1851 the number producing on the Thames and Medway increased rapidly with White's brand from Bazley White's Frost works being the most prominent.

William Aspdin

Picture credit:Dartford museum

Beehive

Picture credit:Dartford museum

Portland cement

Cement works and workers



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Around the mid-century, Isaac Charles Johnson, the Manager at Frost's, carried through some important developments of the Portland process.He discovered the importance of the intermixing of chalk and clay in proportion with water and also the clinkering of the mixture. He also modified the kiln so that the chimney was tapered to increase the draught and thus the temperature.

The cement industry established itself in the area rapidly during the latter part of the 1800s. Abundant supplies of chalk and alluvial clay had made it a natural home for the industry. Cement firms sprang up to take advantage of the growing demand for a product whose true potential had become obvious. Competition was keen and in the early years there were no recognised standards of quality. Chalk was dug with picks, shovels and crowbars and grinding was done by windmills. It was a time of trial and error, but a time nonetheless which established a solid reputation for British cement throughout the world.

Picture credit: Dartford museum

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CEMENT PRODUCTION IN THE 20TH

CENTURY

By 1900 nearly 1,000 bottle kilns were clustered along the estuaries of the Thames and Medway, billowing evidence of an industry growing fast. The rivers were alive with sailing barges weaving to and fro as they supplied the cement firms with vital raw materials and carried the finished product off to its customers. In the chalk quarries close to the river steam shovels dug relentlessly. This was the busy North Kent scene in the year in which the Blue Circle group was born.

As the new century dawned there was growing pressure on cement manufacturers to further improve the methods of manufacture and the quality of the product. Small firms could not hope to raise the capital needed to invest in the new efficient rotary kilns and other sophisticated plant. An amalgamation was the answer and in 1900 24 small firms joined forces to create the Associated Portland Cement Manufacturers Limited, known locally as 'the Combine'. Today the company trades as Blue Circle Industries plc. It has grown from its small beginnings in Kent to become Britain's biggest cement manufacturer and one of the industry's world leaders. Through Whitecliff Properties it developed Crossways Business Park, a centre for business innovation, and with Lend-Lease it has developed Bluewater.

Next topic: Bluewater

Eastern Quarry

Blue Circle, Northfleet works

Picture credit:Blue Circle Industries plc

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