Analytical Summary and Conclusions

The Structures in A.D. 79

Pompeii’s proximity to Rome and its conquest by the Romans in 80 B.C. strongly influenced its development.  The forum was the center of civic and commercial activity.  Public baths and temples could be found throughout the city.  Insulae (city blocks) were laid out in regular patterns, roads were paved and running water was introduced.  

Along via dell’Abbondanza the insulae varied in length between about 70 meters at the western end to about 35 meters in the east.  Most structures along the street had two stories, with occasional overhanging balconies and tile-roofed walkways extending out from the fronts of the buildings. The main entrances of elite houses were about four meters high; other house doorways were about three meters high and shop entrances about three to three and one-half meters high. Residential buildings had few exterior windows as their designs were focused inward on atria and peristyles that were open to the sky.  Shops and workshops had large open fronts with articulated wooden doors.

Natural constituents such as cut stone, rocks, clay, excavated minerals and wood were used as building materials.  Both igneous rocks (such as basalt) and sedimentary rocks (such as limestone) were available in the area.  These materials, for the most part, were amalgamated with Roman concrete and were used to construct buildings in a variety of ways.  Many of these construction methods can be seen along via dell’Abbondanza, including:

  • opus incertum (stone rubble embedded in concrete)
  • opus quadratum (large ashlar blocks)
  • opus vittatum simplex (rectangular tufa block)
  • opus vittatum mixtum (a combination of brick and stone blocks)
  • opus vittatum (alternating brickwork and tufa blocks)
  • opus reticulatum (net-like patterned small square blocks)
  • opus testaceum (fired brick)

Most window and door lintels were wood, but occasionally cut stone was used.  Doors were fabricated from wood.  Structures were roofed with fired clay tiles.

Elite houses and public buildings could be faced with architectural stone but most exterior walls were covered with plaster for protection from the elements and esthetic appeal.  Many walls were decorated with color, designs or images as well as painted dipinti and engraved graffiti advertisements, slogans and street art.

The A.D. 79 Eruption

Pompeii was destroyed by the oft-recounted A.D. 79 eruption of Mount Vesuvius, a stratovolcano located about 10 kilometers north-northwest of Pompeii.  The volcanic event has been classified as Plinian (very intense) and produced a large volume of pyroclastic ash and lapilli (pumice stones). The prevailing winds were towards the southeast during the event, unfortunately putting the inhabitants of Pompeii directly in the path of the ejecta.  It has been estimated that:

  • The ash column extended 20 km into the sky.
  • Three cubic kilometers of pumice and ash were produced.
  • Over four meters of pyroclastic material was deposited during the 30-hour event. The sequence of events was (1) Pumice fall (2) pumice flow (3) ash fall (4) ash flow (5) pyroclastic surge and (6) ash, lapilli and volcanic mud deposits.
  • The temperature of the pyroclastic surge was 350 degrees C.

Lapilli and ash covered the streets, obstructed entrances and filled large voids such as atria and peristyles.  It also accumulated on roofs of the buildings resulting in their collapse.  The power of the pyroclastic surges toppled most of the second stories of the structures that protruded out of the previously deposited material.  

Humans and animals that had remained were crushed by collapsing roofs, trapped inside buildings, knocked down and seared by pyroclastic surges and asphyxiated by gases or ash.  The remnants of the structures were then entombed by additional volcanic material.  In the ensuing centuries the buried organic matter such as flesh, fabrics and wood decomposed.

Condition of the Structures when Excavated

Workers who were digging a water canal tunnel encountered the remains of Pompeii in the sixteenth century.  However, significant exploration did not begin until 1748.  The eruption of Vesuvius had covered the region with four to five meters of pumice and ash that was deposited and compacted in distinct layers corresponding to the phases of the event.  Various governments, treasure hunters and archaeologists have undertaken the subsequent excavation of the buried city for the past 250 years. To date, about two thirds of the area inside the defensive walls has been exposed.

Massive amounts of volcanic material had to be removed to uncover the structures beneath. The basalt-paved streets, stepping-stones and street fountains were found, for the most part, undamaged.  The buildings had suffered significant harm.  Few second stories survived and almost all roofs had collapsed.  Rooms and courtyards were filled with a mixture of tiles from the damaged roofs, pieces of building materials from toppled upper floors and the pumice and ash from the eruption.  Excavators found interior fitments, furnishings and other household and business objects buried in the debris.

Although there are exceptions, the building walls that were found standing are about three and one-half meters high or less.  Many stone door thresholds, pavements and floor surfaces survived.  Wooden lintels rotted during their long burial, leaving most wall sections above doors and windows supported only by the volcanic material surrounding them.  Careless excavation techniques resulted in their collapse.  Numerous surviving walls were found with plaster stucco still attached, and many had painted color and decoration.  

Excavation and Restoration

Early exploration of Pompeii was carried out primarily to locate artwork and antiquities, and consequently much of the spoil containing less interesting items and the original construction materials was discarded.  The remains of the earliest excavations that can be seen today generally consist of only the ground floor walls between the spaces that were originally doorways.

The last half of the nineteenth century saw an important transition in Pompeii from exploitation to examination and analysis.  One of the leaders of this archaeological transition was Giuseppe Fiorelli who developed stratigraphic excavation techniques and innovative conservation and restoration methods. Explorations under the direction of Fiorelli and his successors progressed in the elite houses and other structures in the north, the terraced houses in the south, along the city walls and in suburban areas.  Building remains were better restored, but without second stories.  Fiorelli introduced the system of numerically organizing Pompeii properties by region and city block that is still in use today.  He also discovered that the decomposition of entombed organic materials such as wooden doors and the corpses of the inhabitants left voids in the compacted volcanic ash.  He developed the methodology of carefully filing the cavities with plaster, thereby producing the casts that now evoke such poignant images of Pompeii at the time of its destruction.

Vittorio Spinazzola filled the post of Superintendent of Archeological Works from 1911 until 1923.  Spinazzola transferred the focus of the explorations in Pompeii from the north of the city to the areas between via Stabiana and the amphitheater, which was called the “Nuovi Scavi”.  He planned and supervised the excavation, reconstruction and recording of the facades of eighteen insulae along via dell’Abbondanza as well as portions of Regio I and Regio II.

He directed and supervised the excavation and recording of almost 400 linear meters of via dell’Abbondanza between vicolo del Citarista (close to via Stabiana) and vicolo della Venere (towards the Sarno Gate).  Spinazzola also pioneered new restoration techniques by having the facades and upper stories of buildings carefully consolidated and reconstructed from the top down as they were uncovered.  This not only saved more of the buildings, but also preserved valuable inscriptions and revealed the existence of commercial and industrial facilities as well as the residential properties.

Portions of ground floor walls that were found above door and window openings during Spinazzola’s excavations were conserved by inserting wooden or steel lintels in the old voids, thereby preventing the unsupported sections from collapsing.   Many partially destroyed sections of ground floor walls were rebuilt to their former height using the salvaged materials with construction techniques similar to the original ones.  The few remaining second stories were likewise conserved and some areas completely rebuilt.  Several balconies were partially reconstructed in stone and wood, but with steel beams providing the structural support.  Some of the collapsed tile-roofed walkways were rebuilt with wooden structural members set in the original beam sockets. Where possible, plaster casts were made of the of the cavities of decomposed wood doors and placed in their appropriate doorway openings.  Excavation photographs indicate that decorated plaster walls were cleaned, and some of the more important paintings or slogans were then shielded from the elements by fabric awnings or protective glass covers.

Because of Spinazzola’s new ideas and methods of excavation and the significant efforts of his workers, this section of via dell’Abbondanza is one of the best-preserved and presented areas in Pompeii.  Also, because of the photographs taken during the excavations and the elevation drawings produced by Alberto Sanarica, there exists reasonable documentation that can be used to determine the changes to the structures that have ensued since their excavation.

Analysis of the Post Excavation Changes in the Condition of the Structures

The eruption of Vesuvius not only destroyed most of Pompeii but also entombed the remains for seventeen centuries, which degraded some elements but at the same time protected the structures from further harm.  The subsequent excavations unearthed the fascinating ruins, but once again put them at risk of damage. It is commonly believed that the Pompeii structures and their decorations are deteriorating over time, but the exact nature of degradation is difficult to identify and quantify.

The photography required to produce the photomosaics of via dell’Abbondanza was accomplished between 2005 and 2009.  These photomosaics were used as a baseline to visually explore and analyze the current condition of the structures and, where adequate data could be identified, to compare with historical information about the post excavation state of the buildings.  The following sources were examined in order to obtain the historical documentation used for the condition assessment analysis:

  • Excavation photographs.
  • Excavation orthographic elevation drawings.
  • Hypothetical reconstruction drawings of buildings, insulae and architectural details.
  • Maps and photographs of WW II bombing.
  • Inscriptions (dipinti and graffiti) recorded during excavations.
  • Photographs of the 1879 model of Pompeii in the National Archaeological Museum in Naples.

The objective of this research was to identify materials that showed or described the condition of the structures as close to the time of their original excavation as possible or that documented subsequent changes or alterations. The most descriptive information that was found pertained to the section of via dell’Abbondanza excavated by Vittorio Spinazzola between 1911 and 1923.  The work was documented with both drawings and photographs.  Adequate comparative information was identified for the eighteen insulae excavated by Spinazzola and also for two other city blocks.  For the most part, the analysis therefore identifies the changes that have occurred to the structures for the approximately 100-year period from the early twentieth century to the early twenty first century.

Changes that have occurred to the structures since their excavation were identified for each of the twenty insula by comparing the photomosaic images to the historical information.   Where possible, the cause and extent of the change was also quantified.  The comparisons were organized by insula and have been presented herein (see the menu on the top left of this page) as individual visual panels with side-by-side correlations and, where possible, also documented specific events.

In order to summarize the results of the comparisons, the condition changes associated with each of the city blocks were grouped into the following categories:

Poor Excavation and Conservation Techniques - The first one hundred years of exploration in Pompeii was for loot rather than learning.  The western end of via dell’Abbondanza between the forum and via Stabiana was excavated during this period of plunder between 1814 and 1855.  There is a significant difference in the current condition of the ruins in this section and the structures excavated east of via Stabiana, especially those uncovered by Vittorio Spinazzola between 1911 and 1923.  

The early excavators removed wall paintings and amassed artifacts but did little to salvage materials or conserve the remains of the structures.  Consequently the facades of the structures between the forum and via Stabiana are comprised mostly of the ground floor walls between the door openings.  On the other hand, the fronts of the buildings excavated by Spinazzola between vicolo del Citarista (close to via Stabiana) and vicolo della Venere (towards the Sarno Gate) were carefully excavated, conserved and some even restored.  The difference in the amount of preserved wall surface area that can currently be seen and their state of preservation is dramatic.

The balance of the insulae on the east end of via dell’Abbondanza was explored later in the twentieth century.  The excavators may have been more careful than those in the nineteenth century but the conservation of the remains, especially on the north side of the street, was poor.  Issues that have been identified relating to poor excavation and conservation techniques are listed by insula in the table in the next section.

Damaged or Missing Wall Plaster – Numerous surviving walls in Pompeii were found with plaster stucco still attached after their excavation.  Climatically, the local summers are warm-to-hot and dry, and winters cool-to-cold and wet. The wide range of summer temperatures expands and contracts both walls and floors causing fissures and cracks.  Winter rain infiltrates these breaches and weakens the underlying masonry, which can debond stonework and plaster wall facings.  Plants and weeds can become established in cracks and likewise injure both plaster and masonry.  The curious hands of millions of visitors to the site can also cause harm.  Issues that have been identified relating to damaged or missing wall plaster are listed by insula in the table in the next section.

Faded Wall Painting – Many of the surviving walls in Pompeii also had painted color and decoration.  Exposure to direct sunlight not only degrades plaster but also fades the pigments of unprotected wall paintings.  Over the decades since their excavation the constant exposure to the sun and rain has done significant harm to wall paintings, dipinti and graffiti. Issues that have been identified relating to faded wall painting are listed by insula in the table in the next section.

Damage from Major Climatic Events – The mild Mediterranean climate around the Bay of Naples does sometimes have extremes.  Violent thunderstorms can occur that cause localized severe flooding and damage.  Prolonged wet spells combined with Pompeii’s position on a relatively steep volcanic outcrop can increase the amount and velocity of draining rainwater and put structures at further risk.  Issues that have been identified relating to damaged from major climatic events are listed by insula in the table in the next section.

Damage from WW II Bombing - During the Second World War the US Twelfth Air Force Bomber Command provided strategic and tactical air support to the US Fifth Army after its landing on the beaches of Salerno on September 9, 1943. The mission of the operation was to seize the port of Naples, trap Axis troops in the south and link with the British Eighth Army.  The Combat Chronology of the US Army Air Forces published by Office of Air Force History cites bombing missions on 13, 14, 15, 17 and 23 September over Pompeii and the nearby towns of Torre del Greco, Castellammare di Stabia, Torre Annunziata, Sarno and Nocera that targeted highways, railways, marshalling yards, barracks and gun positions.  An article in Il Giornale d’Italia (No. 205, 27 August 1943) also reported that thirty bombs fell on Pompeii in the vicinity of the forum on August 24, 1943. This bombing mission is not listed in the Combat Chronology.

After these events it became evident that the Bomber Command failed to distinguish between the modern town of Pompeii and the ruins during its selection of targets. No fewer than 150 bombs fell on ancient Pompeii.  Damage was widespread including the destruction of the local museum.  Fortunately Amedeo Maiuri, the Soprintendente Archeologica di Pompei during this period, had directed that selected statues and other artifacts be removed and stored elsewhere.  

Vittorio Spinazzola’s book Pompei alla luce degli scavi nuovi di Via dell'Abbondanza (anni 1910-1923) contains a map that shows the location of 13 bombs that fell along the eastern end of via dell’Abbondanza.  Unfortunately the bombs fell in a line down the street causing extensive damage to a number of insulae.  To the extent possible the buildings were repaired and reconstructed after the war.  However, there is probably no other single event in the post-excavation history of Pompeii that has caused the loss of more architectural and historical information. Issues that have been identified relating to damage from World War II bombing are listed by insula in the table in the next section.

Earthquake Damage – An earthquake measuring nearly 7.0 on the Richter Scale took place in southern Italy on Sunday, November 23, 1980.  The quake was centered on the village of Conza in the Irpinia region about 40 kilometers east of Naples. The event killed nearly 3,000 people and left 300,000 homeless.  Although not immediately close to Pompeii, numerous fragile structures across the ancient city were harmed.  Issues that have been identified relating to damage caused by the Irpinia earthquake are listed by insula in the table in the next section.

Other Structural Issues - All structures deteriorate as they age.  Foundations settle, materials decompose and structural members fail.  At the time of Pompeii’s destruction, the buildings there were already decades-to-centuries old and had been subjected to daily use by the inhabitants, all types of weather and a severe earthquake in A.D. 62.  The excavation of the buildings and exposure to the elements also placed stress on the remains of the structures. Structural issues that have been identified are listed by insula in the table in the next section.

Analysis of the Changes in the Condition of the Structures

As has been described, the via dell’Abbondanza photomosaics were used to analyze the current condition of the structures.  They were then compared to historical images and data for the twenty insulae along the street for which information of reasonable quality had been located.  Changes that have occurred to the structures since their excavation were identified and, where possible, their causes and extent quantified.  The changes in the condition of the structures associated with each of the city blocks were analyzed and grouped into the previously defined categories and recorded in the following table:

 

Regio &
Insula
Poor Excavation & Conservation Techniques Damaged or Missing
Wall Plaster
Faded Wall
Painting
Damage from
Major Climatic Events
Damage from
WW II Bombing
Earthquake
Damage
(1980)
Other
Structural Issues
VII, 9   Majority has
perished
Little color
remains
      E end - two doorway lintels repaired
IX, 7   W end - majority has perished
E end - some damage
E end - moderate
fading
      E end - balcony required repair
IX, 11   W end - some damage
E end - majority has perished
W end - moderate fading
E end - major fading
       
IX, 12 Late 20th century
excavations added unsightly roof supported by scaffolding
W end - destroyed by bombing
E end - significant damage
Major fading   W half of block - destroyed &
reconstructed after
WW II
  E end - balcony now
supported by scaffolding
IX, 13   W end - almost all destroyed by bombing
E end - majority has perished
Little color remains   W corner - damaged and reconstructed after WW II and second story added    
III, 1   Little plaster when
excavated - the remains are damaged
Little color remains   E corner - damaged and reconstructed after WW II    
III, 2   W end - almost all destroyed
E end - little plaster when excavated
Major fading   W corner - destroyed
and partially reconstructed after WW II
E end - structural support required  
III, 3 The modern concrete roof built as a period reconstruction over III, 3,6 collapsed due to heavy rainfall Majority has
perished
Little color remains E end - complete
structural collapse due to heavy rainfall
Center - destroyed and
partially reconstructed
E corner - damaged and reconstructed with roof after WW II
   
III, 4   Majority has
perished
Major fading   Damage to interior
spaces
   
III, 5 E end - in poor condition
due to original excavation technique
W end - little remains
E end - significant damage
Major fading   E corner - damaged
W corner - reconstructed balcony
destroyed by bombing
   
III, 7 In poor condition
due to original excavation technique
None remains between III, 7
doorways 5 and 6
  Wall between III, 7
doorways 5 and 6 collapsed due to heavy rainfall
     
I, 6   W end - majority has perished
Center - some damage
E end - significant damage
Center - moderate fading
E end - major fading
  Damage to interior
spaces
   
I, 7   Much has
perished
Major fading        
I, 8   Majority has
perished
Little color remains     Structural support
required
 
I, 9   W end -little plaster when excavated and almost none remains
E end - majority has perished
Little color remains        
I, 11   W end - significant damage
E end - majority has perished
Little color remains        
I, 12   Much has
perished
Major fading     E end - structural support required for roof  
I, 13   Almost all has perished Little color remains       One doorway has been filled
II, 1   Almost all has perished Little color remains       Small balcony required
reconstruction
II, 2   Almost all has perished Little color remains   W corner damaged and plaster door cast destroyed    


Summary of the Changes in the Condition of the Structures

The table above records the result of the analysis of the via dell’Abbondanza photomosaics when compared to historical images and data.  The following summarizes the changes in the condition of the structures, by category, as recorded in this tabulation:

Poor Excavation and Conservation Techniques – Four insulae have been affected by the quality of the original excavations or subsequent conservation projects:

  • Two of the insulae were not well consolidated during excavation, which has weakened the structures - III, 5 and III, 7.

  • A modern concrete roof was built as a period reconstruction over III, 3, 6 that contributed to the collapse of the building in 2010 during a heavy rainfall.

  • Excavations in insula IX, 12 during the late 20th century required the addition of an unsightly roof that is supported by scaffolding.

Damaged or Missing Wall Plaster – All twenty insulae experienced degradation of, or damage to, the plaster wall facings:

  • Four of the insulae have suffered some loss or damage to the wall plaster, but still have well-preserved sections - IX, 7 (conserved in 2005); IX, 11 (conserved in 2005); I, 6; and I, 12.

  • Eight of the insulae suffered loss or damage to the wall plaster, but still have discernible remnants - VII, 9; IX, 12; IX, 13; III, 2; III, 4; I, 7; I, 8; and I, 11.

  • Eight of the insulae have almost no remaining plaster, or the remains are in very bad condition - III, 1; III, 3; III, 5; III, 7; I, 9; I, 13; II, 1; and II, 2.

Faded Wall Painting – Nineteen of the insulae have some remaining wall plaster.  All nineteen have experienced some degree of fading of the painted wall surface decoration:

  • Three of the insulae have suffered some fading to the decoration on the remaining wall plaster, but still have well-preserved sections - IX, 7 (conserved in 2005); IX, 11 (conserved in 2005); and I, 6.

  • Six of the insulae have suffered major fading to the decoration on the remaining wall plaster, but still have discernible remnants - IX, 12; III, 2; III, 4; III, 5; I, 7; and I, 12.

  • Ten of the insulae have almost no color left on the remaining plaster - VII, 9; IX, 13; III, 1; III, 3; I, I, 8; 9; I, 11; I, 13; II, 1; and II, 2.

Damage from Major Climatic Events – Major climatic events (rainstorms) caused structural collapses in two of the Insulae:

  • A building in Insula III, 3 collapsed in 2010 and a wall in Insula III, 7 in 2009.

Damage from WW II Bombing - WW II bombing damaged nine of the insulae:

  • Three insulae were severely damaged (large sections destroyed) - IX, 12; III, 2; and III, 3.

  • Four insulae were damaged (smaller sections damaged or destroyed) - IX, 13; III, 1; III, 5; and II, 2.

  • Two insulae were damaged on the interior - III,4; and I, 6.

Earthquake Damage – The 1980 earthquake structurally damaged at least three of the insulae:

  • III, 2; I, 8; and I, 12.    

Other Structural Issues - Five insulae required structural repairs or shoring unrelated to either the bombing of Pompeii or the 1980 earthquake:

  • VII, 9 (repairs to doorway lintels), IX, 7 (repairs to a balcony), IX, 12 (support for a balcony was required), I, 13 (doorway filled) and II, 1 (small balcony reconstructed).

Conclusions

It is commonly believed that Pompeiian structures and their associated decorations are deteriorating over time, but this has been historically difficult to identify and quantify except for anecdotal examples.  This condition assessment analysis can possibly give some objective indication of the problems to which the structures have been exposed.

The analysis studied twenty insula along via dell’Abbondanza.  They were selected because historical data was identified that matched the newly created photomosaics that would enable comparisons to be made. The study was not designed as a city-wide statistical survey and, therefore, direct correlations with other parts of Pompeii would be more indicative rather than conclusive.  The following can be derived from the analysis data:

  • Two of the insulae (10%) have experienced major structural failure due to poor consolidation or restoration combined with major rainfall.

  • All twenty of the insulae (100%) experienced some type of degradation or damage to the plaster wall facings.  Of these, eight (40%) experienced damage to the wall plaster so severe that almost none remains, or the condition is very poor.  Four (20%) still have some sections of well-preserved wall plaster.

  • Nineteen of the insulae that remain standing (95%) have experienced some degree of fading of the painted wall surface decoration.  Of these, ten (50%) have almost no color left on the remaining wall plaster.  Three (15%) still have some sections of painted wall plaster with discernible color or design.

  • Nine of the insulae (45%) were damaged by WW II bombing.  Three of these (15%) had large sections of their facades destroyed.

  • At least three of the insulae (15%) were structurally weakened during the 1980 earthquake. These are the only areas of damage that could be identified in the available archive photographs, and the harm could have been more extensive.

  • Five of the insulae (25%) required structural repairs or shoring unrelated to either the bombing of Pompeii or the 1980 earthquake.  These are only the repairs identified with the available research materials.  Any other structural issues would not have been revealed by this comparative analysis.

Infrequent events have caused major harm. The most disastrous incident on via dell’Abbondanza in the last 100 years was the bombing of the city by the allies during WW II.  Large sections of three insula were destroyed and major damage done to the facades of four other city blocks.  Heavy rains combined with blocked or insufficient surface water drainage contributed to the collapse of one major building and a wall.  Other structural damage has been caused by the earthquake of 1980 and failures of restored balconies. The cantilevered balconies appear to be very susceptible to degradation and failure.  For the most part, the various structures have been rebuilt or repaired.

Day-to-day exposure to the sun, rain, wind and native flora has gradually taken its toll on the structures.  All of the analyzed insula experienced some level of loss of wall plaster and fading of wall paintings.  In approximately half of these city blocks, the damage or loss was severe.  This type of damage cannot be easily repaired, and the information and charm conveyed by ancient painted designs, signs, dipinti and graffiti are now gone.  The best-preserved remaining plaster and wall paintings are those under roofs and those that have been protected by hanging awnings or glass covers.

The authorities in Pompeii have an important but unenviable task.  The city is large and the wear is constant, punctuated by major natural and manmade events.  Although they do excellent work preserving and repairing the ruins their resources are finite.  Additional funding for conservation and repair projects would certainly assist them in their mission.

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