The cone of Mount Somma, Kingdom of Naples, c 1776.

Hand-coloured etching by Peter Fabris (active 1768-1779), after his own drawing. Illustrated plate from William Hamilton's study of Italian volcanoes, 'Campi Phlegraei' (published in Naples, 1776). View of the inside of the cone of Mount Somma from the valley between Mount Somma and Mount Vesuvius, southern Italy, showing horizontal and perpendicular strata of lava, loose volcanic cinders and ash mixed with fragments of lava. Hamilton's book is a seminal work on the nature and effects of volcanic explosions.