This book provides an excellent introduction to the study of volcanoes, both on Earth and in the Solar System in general, which is easily accessible to an interested amateur or an undergraduate in the early stages of their degree (it was recommended reading for several of my first year courses as an undergrad geologist). The late Professor Francis produced a work that is both informative and entertaining, whilst at no time trivialising the subject matter in hand. Pertinent examples and analogies are provided to clarify and illuminate rather than to dumb-down - a distinction sadly lacking from many other volumes covering similar topics. For a more comprehensive coverage of the topic, I would recommend referring to this book alongside either Igneous Petrology by Anthony Hall or Igneous Petrogenesis by Marge Wilson.