In 1783 Erasmus Darwin, grandfather of the famous scientist Charles, and his family moved to Full Street in Derby, where renovations to the house included improvements to the water supply. He deepened an old polluted well near the house in the expectation that he would intersect the same water-bearing sand that fed St. Alkmund's Well about 800 m to the north. Good quality water was obtained, which overflowed at the surface. The success of his well depended on higher heads at depth in a zone of groundwater discharge rather than direct hydraulic continuity between sands in his well and those cropping out on higher ground to the west. Despite some claims, Darwin was not the first to state clearly the principle underlying overflowing wells. In Europe this distinction can be claimed by Bernard Palissy, writing some 200 years before Darwin. A hundred years later, Bernardino Ramazzini speculated correctly on the origin of the overflowing wells of Modena. Darwin's main contribution lies in his early application of geology to the solution of a water supply problem.