Charles Darwin (1809–1882) published Observations on the Volcanic Islands in 1844. It is one of three major geological works resulting from the voyage of the Beagle, and contains detailed geological descriptions of locations visited by Darwin including the Cape Verde archipelago, Mauritius, Ascension Island, St Helena, the Galápagos, and parts of Australia, New Zealand and South Africa. Chapter 6 discusses the types of lava found on different oceanic islands. There is an appendix of short contributions by two other scholars: descriptions of fossil shells from Cape Verde, St Helena and Tasmania by G. B. Sowerby and of fossil corals from Tasmania by W. Lonsdale. The book is illustrated with woodcuts, maps and sketches of specimens. It provides valuable insights into one of the most important scientific voyages ever made, and the development of Darwin's ideas on geology.