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

For Hamilton, this methodology corresponded to a specific poetics. His descrip-tions aimed at a sober recording of facts, as he explains in his concluding letter to Joseph Banks in the supplementary volume: “As many Poetical descriptions of this eruption will not be wanting, I shall confine mine to simple matter of fact, in plain prose, and endeavor to convey to you, Sir, as clearly, and distinctly, as I am able, what I saw myself, and the impression it made upon me at the time, without aiming in the least at a flowery stile” (Hamilton 1779: 5). It is no coincidence that with the descriptive ideal “clearly, and distinctly” Hamilton ties in with Descartes’s criteria of clair et distinct, with which the latter had co-founded modern science.

With the help of his precise observations and his evidence-based conclusions, Hamilton made geological and volcanological discoveries: He recognized that volca-noes change the landscape and produce mountains, especially in areas of increased volcanic activity, such as the Phlegraean Fields, and that their age and history can be traced by their ejections. Even inactive volcanoes can be identified by traces of their past eruptions. Many volcanoes have similar features: the cone shape, the crater with a hill in it, lateral outlets of lava, weathering by vegetation and lake formation in the eroded crater, a gradual breaking off of the flanks in extinct volcanoes, etc. Based on the amount of ejected material and against widespread assumptions, Hamilton de-termined that the combustion chamber of a volcano does not sit at its top and derive from coal deposits beneath the surface, but actually lies deep below the mountain and is fueled by underground fires, possibly interconnected over long distances, form-ing chains of fire mountains. Last but not least, Hamilton was able to describe recur-ring elements of volcanic activity based on the multiple eruptions he witnessed, such as the rhythmic alternation between ejection and quiescent phases or the mineralo-gical composition of the erupting lavas and rocks. Using signals such as quakes, ground thunder, and gas emissions, he tried to infer patterns for predicting eruptions.

Hamilton made a seminal contribution to the history of science. By studying the course of successive volcanic eruptions and recording their chronology from their traces, he added a temporal dimension to geology – and thus contributed to a gen-eral trend of temporalization in the sciences around 1800: The concept of time en-tered natural history. As in paleontology and later in biology with Charles Darwin’s theory of evolution, geology developed an awareness of the historical variability of nature and of a prehistoric, prehuman deep time. This extensive temporal concept clearly contradicted the Judeo-Christian myth of creation and the naive assumption that the Earth was only a few thousand years old.