Rock fragments from Mount Vesuvius, c 1770.
© Science Museum / Science & Society Picture Library
Hand-coloured etching by Peter Fabris (active 1768-1779). Illustrated plate from William Hamilton's study of Italian volcanoes, 'Campi Phlegraei' (published in Naples, 1776). Specimens of stone collected by Hamilton on Mount Vesuvius, which are (1,2,3,4) calcarious matter found in the soft tufa strata of Fose Grande, (6) lava enclosed in white marble and (7) striped marble. Based on letters sent to the Royal Society, Hamilton's book is a seminal work on the nature and effects of volcanic activity.