The Cape Verde Islands

After three weeks at sea the Beagle made landfall at St Jago, a volcanic island in the Cape Verde Islands. Here Darwin energetically collected, tested, and identified rock samples, constructing a cross-section of the island’s strata from which he deduced a sequence of eruptions and long cyclical periods of subsidence and uplift. ‘St Jago is singularly barren & produces few plants or insects. – so that my hammer was my usual companion, & in its company most delightful hours I spent.’ On 15 February they arrived at the remote barren islets of St Paul’s Rocks, and Darwin’s geological hammer was put to work again. Some interesting insights occurred to Darwin: ‘Is it not the only island in the Atlantic which is not Volcanic?’ It wasn’t just rocks that fell victim to Darwin’s hammer on St Paul’s: FitzRoy later described how ‘The first impulse of our invaders of this bird-covered rock was to lay about them like schoolboys; even the geological hammer at last became a missile’.