Sir Charles Lyell (1797–1875) was one of the most renowned geologists of the nineteenth century. His Principles of Geology (also reissued in this series) laid the foundations of evolutionary biology, and greatly influenced Darwin. Lyell's most important contribution to modern geology was his refining and popularising of the concept of uniformitarianism, the idea that the earth has been formed through slow-acting geological forces over billions of years. These volumes, first published in 1845, are the result of Lyell's 1841 lecture tour across the United States and Canada, in the course of which he made many observations on the formation of the American landscape. Using the popular format of a travel diary, Lyell provides vivid and detailed descriptions of North American geology, with discussions of important geological sites. Volume 2 contains his travels in Canada.