"physical geography" starts with describing the overall structure of planet earth, and a brief allusion to the location of the earth within the solar system. subsequently, the book focuses on terrestrial topics, such as the most basic features of land and water, and formations such as mountains, volcanoes, oceans, rivers and lakes. somerville goes on to discuss the elements that govern temperature, such as light, electricity, storms, the aurora and magnetism. eventually the book turns to vegetation, birds and mammals, and their geographical distribution on the planet in the arctic, europe, asia, africa, america and the antarctic. somerville ends the book with a discussion of "the distribution, condition, and future prospects of the human race".< somerville emphasises the reciprocal dependencies in physical geography and the relationship between human beings and nature. in line with victorian thinking, somerville asserts the superiority of human beings, but maintains the interdependencies and interconnectedness of creation. "physical geography" sold more copies than any of her other books and earned humboldt's admiration. after receiving a copy of the book he wrote to somerville: "you alone could provide your literature with an original cosmological work".