Darwin's theory of Coral Reefs, developed between 1835 and 1842, is commonly interpreted as subservient to his geology—constructed in order to provide evidence of subsidence contrary to the elevation he witnessed in South America. Recent work has broadened Darwin's motivations to the day-to-day affairs of hydrography and emphasized his reliance on plant biology.
In this paper, I have two primary goals: (1) to bring out the hydrographical elements to their fullest extension by showing why the features of coral reefs Darwin targets were so critical for the Admiralty at an institutional level, partly due to the work of the its first Hydrographer, Alexander Dalrymple (1737-1808), and to make clear how such programmatic influences determined the earliest articulation of Darwin’s theory. And, (2) to show how solving the hydrographical problems provided by the Admiralty required Darwin to apply and develop a robust, biological notion of a “station” which captured the different kinds of coral along with their ecological role. For the Admiralty coral reefs served as instruments—their structure helping to predict the weather patterns a ship Captain could hope to encounter. Because Darwin’s concept of a station was highly relational and sensitive to ecological perturbations, this led him to repeatedly conclude that the structure of coral-reefs was not always useful in predicting surrounding conditions or where yet unknown coral reefs might lie. Such ecological considerations heavily constrained what could be learned about the geology/hydrology of a particular region from its reefs.
