Abstract Gottfried Wilhelm Leibniz visited the Harz Mountains more than thirty times and spent almost three full years there between 1680 and 1686. His aim was to install wind machines for draining the Harz silver mines. Despite Leibniz’s best efforts—his commitment bordered on obsession—the enterprise ultimately failed. There is still disagreement about exactly what happened. Biographers and historians have mostly asserted that Leibniz, a universal genius dedicated to the greater good of science and society, was thwarted by stubborn mining officials. Historians of mining, on the other hand, have generally sided with the “professionals” in the Hannoverian mining administration. This essay investigates Leibniz’s wind machine project and the narratives it has spawned. Using both Leibniz’s published correspondence and unpublished memoranda from the Clausthal mining office, it attempts to answer a series of questions: Was Leibniz thwarted by the mining office? Was he an outsider or an insider? An amateur or a...