Geography is often defined in terms of two branches&colon; human geography and physical geography. These areas are different in geology, geography, and culture. Advances were realized in the fields of travel literature, cartography, geography, and scientific education. No single definition of culture dominates within cultural geography. It is inseparable from the geography and ecology of Earth. Snow's study is part of the history of public health and health geography. Physical geography (or physiography) focuses on geography as an Earth science. This is mostly due to the unique geography of the continent. The Society also has competitions for students studying geography. Tahtawi was instrumental in translating military manuals, geography, and European history. Species diversity varies by geography and diet. These were often sprawling accounts that included details of both geography and history. Within those regions are five distinct areas, based upon natural geography and population concentration. Industrial employment influenced the economic geography of Perth. These projects helped Pei conceptualize architecture as part of the larger urban geography.