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Vesuvius & Campi Flegrei

Volcanological phenomena in the paintings by Fabris and Hamilton

Clicking the small image will open a larger one (60-80K). The images below were mainly scanned from: «Les Fureurs du Vésuve» Découvertes Gallimard Albums; GT 10037 (ZB Zürich); Originals in: Hamilton, William: «Campi Flegrei. Observations on the volcanoes of the two Sicilies as they have been communicated to the Royal Society of London», Naples 1776. Text in collaboration with A. Bernhard and P. Leresche, class 6a HS 2000/01 KZU Bülach, Switzerland.

Vesuvius very similar to what it looks even today: On the right the central stratovolcano and on the left the wall of the caldera (Monte Somma) which surrounds the central cone. Before the eruption of 79 AD Monte Somma was part of the flank of a taller volcano. During the eruption of 79 AD this volcano collapsed. During later eruptions the central cone was built to its present height which is somewhat greater than Monte Somma's.

Dikes in the inner wall of the Somma-Caldera. The lava of the dikes is somewhat more resistant to erosion than the rest. Therefore they protrude from the all. The persons below left are standing of ropy pahoehoe lava which was erupted in January 1778.

The cinder cone, which was built by strombolian eruptions within the main crater, is ejecting bombs. The observers approach the cone from the upwind side in order to avoid being endangered by lapilli, ash and gases. They are standing on a solidified lava flow, which has flown around the central cone (before the great eruption of 1767).

Series of images showing the growth of the cinder cone as a result of strombolian eruptions. THe corresponding dates are: 1.) 8.7.1767 - 2.) 25.7.1767 - 3.) 6.8.1767 - 4.) 17.8.1767 - 5.) 3.9.1767 - 6.) 18.10.1767 which is only one day before a great eruption! Full of excitement Hamilton wrote: «I saw this small mountain grow... I now have no doubt that the whole of Vesuvius came into being in this particular way».

On the evening of 8. August 1779 Vesuvius, during a plinian eruption, ejects a colossal lava fountain which reaches an altitude of 4000m above the crater. The ash-laden eruption cloud is full of lightning and enormous amounts of tephra fall even outside the Somma wall (left).

In the morning of 9. August 1779 the plinian eruption continues. The eruption column is mainly white indicating that the amount of erupted tephra has diminished. But still many bombs are ejected which are still visible at this great distance. After their parabolic flight they crash into Valle del Inferno (between the central cone and Monte Somma).

Pietro Fabris here shows drastically an effusive eruption which produces mainly fluid lava descending as a lava flow and covering a farm (20. October 1767). Monte Somma stops damage further north. Despite the ever-present risks the people of the region have continued to farm Vesuvius' slopes.

A typical pahoehoe lava flow shows strange surface features: a ropy surface is caused by compression of an already hardened crust ontop of still flowing lava. In the left dikes in the inner wall of Monte Somma. Presently steam emission is the only activity at the main crater. In those days ladies were carried up the mountain in seddan-chairs.

A aa lava flow (recognised by the broken surface texture) passes the observer's location on 11. May 1771 and reaches the sea at Resina. Note the steep, slowly advancing front of the flow. Pietro Fabris is amongst the spectators (below left) as is William Hamilton, who explains the view to other onlookers.

During a flank eruption a lava flow is erupted from a cinder cone on Vesuvius' flank (1760). Activity at the central crater is low. Lateral eruptions cause great damage to farmland and buildings but usually there is enough time for people to reach a safe location.

In Pompeij excavations were made already in Hamilton's time! Pompeij was covered by several meters of ash 79 AD during a gigantic plinian eruption of Vesuvius. The city was totally destroyed and about 2000 were killed. The diggers shown in the painting are less interested in scientific findings than ancient treasures which they hope to sell later on.

Sir William Hamilton (left) was born in 1730 in Scotland. As British ambassador he came to Naples in 1764 where he remained until 1800. He was fascinated by Vesuvius and his studies were favoured by the many eruptions of the volcano at that time. He sent many rock sample to England and commissioned the artist Pietro Fabris to draw and paint the volcanic phenomena (pictures on this page). He also interviewed local farmers and climbed Vesuvius at least 200 times.

Pietro Fabris (1756–79) was an Italian artist mainly based in Naples. Nevertheless he called himself an «English artist». 1768 he exhibited in London at the Free Society and in 1772 at the Society of Artist».