Before the invention of the sawmill, boards were split (‘rived’) and planed or sawn by two men with a two-handled whipsaw. ‘Saddleblocks’, or ‘dogs’, were used to hold the log in position over a sawpit. It was exhausting work, especially for the top sawyer, who had to balance on the log, guide the saw, and didn’t have the pitman’s advantage of gravity. Early sawmills adapted the whipsaw to mechanical power, generally driven by a waterwheel. A connecting rod known as a ‘pitman arm’ (the origin of a term now widely used) converted the circular motion of the wheel to the back-andforth motion of the saw blade. Circular-saw blades were invented around the late 17th century. ‘Gangsaws’, which had several parallel blades so that a log could be reduced to boards in one step, soon followed. Circular-saw blades were prone to damage by overheating or dirty logs, giving rise to a new technician, the sawfiler, whose job was to set and sharpen teeth. Mills became highly mechanized with the advent of steam power in the 19th century, and further so with electricity. Most aspects of sawmilling are now computerized.