CHARLES DARWIN; THE MAKING OF THE NATURALIST AND GEOLOGIST IN CAMBRIDGE AND WALES

Darwin had a three-way connection with Wales first through his own frequent visits, secondly through Henslow and thirdly Sedgwick, who in a few weeks created a fine geologist.

From a child Darwin visited Wales and explored the countryside frequently observing the natural history. What he learnt was of two-fold benefit for the Beagle voyage and subsequent work. He learnt to cross wild country by horse or foot, whether a gentle horseride near Welshpool or his serious hikes in the late 20s, culminating in his four-day trek from Cwm Idwal to Barmouth in 1831, which is no mean feat today. This prepared him for his Beagle treks. Alongside this was his natural history, which took precedence to his official studies, and gave him a holistic view of natural history from beetles to the poor birds on Bird Rock. This effectively gave him several annual field-trips alongside his work in Edinburgh, Shropshire and Cambridge.

For the student “who walked with Henslow” most emphasis is given to natural history as Henslow was a botanist. However Henslow was a highly skilled geologist as his 1822 memoir on Anglesey shows. Darwin took this memoir on the Beagle, annotated it, drew comparisons with South American geology and wrote a private paper on it. Darwin made two pages of notes on Anglesey rocks and almost certainly went round Anglesey with Sedgwick armed with the Memoir.

The greatest Welsh connection was his geological trip with Sedgwick, which probably lasted 18 days. It gave him a grounding in all field geology, especially, on igneous rocks. Reading his notes in order shows the rapid progress and those made on his own from Idwal to Barmouth show considerable perception.

Many of his skills learnt in Wales were used on his voyage, especially on igneous rocks from the Cape Verde to the Galapagos and on Falklands geology. His Welsh experiences were never far away. This was of more importance than his reading of Lyell.

Darwin’s last field-trip in 1842 demonstrates his perception and willingness to change his mind over glaciation, having initially rejected the theories of Charpentier and Agassiz. It is fitting that this trip formed an interlude during his writing the first essay on Natural Selection.