Lyell's interpretation of geologic change as the steady accumulation of minute changes over enormously long spans of time, a central theme in the "Principles", influenced the 22-year-old Charles Darwin, who was given the first volume of the first edition by Robert FitzRoy, captain of HMS "Beagle", just before they set out (December 1831) on the ship's second voyage. On their first stop ashore at St Jago, Darwin found rock formations which—seen "through Lyell's eyes"—gave him a revolutionary insight into the geological history of the island, an insight he applied throughout his travels.