Since the Second World War interest in the active by Italian geophysicists; studies of ground deform­ volcano Mount Etna, in Sicily, has been steadily ation by British and Italian groups; measurements increasing. This interest has not been restricted of microgravity changes particularly by a British to Italy, and scientists from Belgium, France, group; endeavours to improve analytical tech­ Germany, the United States and the United King­ niques for gases and sublimates by French and also dom have played a part in volcanological studies. Italian and British workers; pioneering work on In 1972 much of this work was drawn together at a rheology of lavas and growth of lava fields by discussion meeting convened by the Royal Society British scientists; and greatly improved surveil­ of London and attended by representatives of most lance of activity, notably that occurring in the summit region. of the projects that were being conducted on Etna. The meeting served to draw together current It is a principal aim of this book to synthesize the knowledge of Etna, especially information derived results of these many different studies into a more during the 1971 flank eruption, and also to point complete understanding of the volcano. Inevitably out deficiencies in knowledge and methods of the coverage is somewhat uneven; some fields of approach to investigating the volcano. In his study have been researched more thoroughly than opening statement to the meeting Professor A. others.