Scheme of the Roman Hierapolis stone sawmill. The 3rd century AD watermill is the first known machine to incorporate a crankshaft and connecting rod. Image File:Römische Sägemühle.svg based on Tullia Ritti, Klaus Grewe, Paul Kessener: "A Relief of a Water-powered Stone Saw Mill on a Sarcophagus at Hierapolis and its Implications", Journal of Roman Archaeology, Vol. 20 (2007), pp. 138–163 (148, fig. 10) and uploaded to Wikimedia Commons by chris 論, licensed under the Creative Commons Attribution 3.0 Unported license.