William Robert Grove is one of the forgotten giants of nineteenth-century science. The improvements in battery technology developed by him helped power the Victorian telegraph; his essay On The Correlation of Physical Forces was widely recognised as a major contribution to natural philosophy; and he was the driving force behind the mid-century reform of the Royal Society. This book follows his scientific career and the culture of Victorian science within which he worked, to explore the ways in which he contributed to forging a distinct Welsh scientific identity in the nineteenth century.