Rivers of molten rock obliterating all in their path, earth tremors, toxic gases and a pall of smoke spreading across the skies - volcanoes and their devastating effects have been shrouded in legend since the dawn of time. Once thought to be outpourings from Hell or the work of other supernatural forces, these extraordinary geological phenomena are now more clearly understood, thanks to vulcanologists who have dared to approach Vesuvius, Etna, Stromboli, Mount St Helens or Cotopaxi. Maurice Krait, a world expert on volcanoes, completed this study shortly before his death in the eruption of Mount Unzen in Japan.