Cornelis took out a patent on his sawmill on December 15, 1593, and on the pitman arm device on December 6, 1597. Early sawmills adapted the whipsaw to mechanical power, generally driven by a water wheel. The circular motion of the wheel was changed to back-and-forth motion of the saw blade by the pitman arm or rod. A pitman is similar to a crankshaft, but in reverse (a crankshaft converts back-and-forth motion to circular motion). Several early sawmills in England were burned by sawyers who were fearful of losing their livelihoods. However, the increased efficiency of the sawmill, and the back-breaking nature of the saw pit work, resulted in saw pits generally going out of use in the United Kingdom at the time of the industrial revolution. Old OS maps circa 1860 often show the location of saw pits, but by the start of the 20th century very few remained and most are no longer in use. Roy Underhill tells the tall tale, or tongue-in-cheek story, that, after the development of steam-powered sawing machines, saw pits were unnecessary, and therefore were cut up and sold as post-holes. The Royal Dockyards Saw pits were introduced into the Royal Dockyards of Britain in the mid 18th century. Before their introduction, trestles were used to support the log, and a frame saw employed for the cutting. In the Royal Dockyards saw pits, the upper sawyer was called the 'Topman;' he followed the marked line to make a straight plank, and the 'Underman' pushed the rib, pit or whip saw. The logs were held firmly in place by 'G' shaped clamps called 'dogs' that were hammered into the log being cut. The pits were usually lined with elm wood, which withstood damp. Access to the saw pit was via steps or a ladder at one end. The sawyers were paid by the 100 foot runs, with pay related to the difficulty of sawing the wood, oak being the highest paid. Usually the sawyer was responsible for sharpening the saws, however on occasion a whet man was employed to do that work. Around the world Australia Saw pits provided much of the sawn timber for Australia during the 1800s. Convicts were put to work in saw pits as a punishment in penal colonies in Tasmania. Saw pits also featured in some of the most significant events of early european Australian settlement. In August 1788, William