The Aesthetics and Politics of Volcanoes: William Hamilton’s Campi Phlegraei

Hamilton recognized that nature evolved slowly, despite the dramatic catastro-phes he observed in the eruption of volcanoes. He thus took a mediating posi-tion in a wider debate on natural history that was to continue into the middle of the 19th century. The followers of so-called catastrophism, as represented by the French naturalist Georges de Cuvier (1769–1832), assumed that the history of the universe, our earth, and all living beings was determined by disruptive events. They held floods, meteorites, earthquakes and eruptions responsible for the shape of the Earth, the development of life, but also for mass extinction. The opposite po-sition is represented by so-called uniformitarianism (also “gradualism”), conceived by the British geologists James Hutton (1726–1797) and Charles Lyell (1797–1875) (Hutton 1788: 209–304, Lyell 1830–1833, Lyell 1863). According to this principle the geo logical processes on earth run uniformly and slowly. Even major upheavals re-sult from the interaction of many small changes.

Today we know that both models have their justification. Catastrophic and grad-ual processes in nature interact. Hamilton, too, considered both punctual eruptions and incremental developments in his explanations of earth’s history. The scale of his geological chronology was formed by the abrupt ejections that covered Pompeii, as well as by the deposits of earth that gradually accumulated above them. The in-terval between the eruptions could be measured by their thickness. The history of the Earth could be read from their layers.

The picture plates in Campi Phlegraei illustrate Hamilton’s theory of the vol-canic origin of the Phlegraean Fields and thereby of the whole region around Na-ples. In addition to active Vesuvius, they show extinct volcanoes, weathered craters, volcanic islands and crater lakes, solidified lava flows, and rock layers that formed in prehistoric times. The geological purpose of his work is most clearly expressed, however, in the illustrations of the rock collections that Hamilton sent to the Royal Society for examination (plates XXXXII–LIIII and IIII–V of the supplementary volume of Campi Phlegraei).

Even these illustrations, however, are not entirely scientific: On Plate LIIII, a colorful gem is shown protruding from the gray rock in the midst of geological specimens. It is, as Hamilton explains in the caption, a headdress set with gems from the Vesuvius region, as worn by the ladies of Neapolitan society. Even in the taxonomic part of his illustrations that seems to offer the least scope for artistic rendition, Hamilton alludes to festivities, arts and crafts, and relates aesthetics to volcanology.

Volcanic eruptions have consequences for climate, society and culture. The eruption of Tambora on the island of Sumbawa near Java in 1815, for example, was a global event. Its ash and smoke were ejected so far into the stratosphere that they reached Iceland, where they are still detectable in the ice today. They reached Europe, where they triggered a “year without a summer” in 1816, bringing darkening and cold, precipitation and floods, a decline in harvests, famine, disease and emigration.