Adam Sedgwick (1785–1873) is chiefly remembered as one of the founders of modern geology and an early mentor of Charles Darwin. Originally published in 1890, this two-part collection is composed of extensive extracts from Sedgwick's letters together with a rich, detailed account of his life and work. Both volumes are thoroughly researched and edited by J. W. Clark, with assistance from T. M. Hughes. Sedgwick was a contradictory figure who combined devotion to science with a conservatism borne of his strong religious beliefs. Whilst the text is limited in its portrayal of these contradictions as a result of proximity to its subject, this remains a well-rounded portrait that will be of value to anyone with an interest in geology or the history of science. Volume I covers the period 1785 to 1840.