SHEILA TERRY / SCIENCE PHOTO LIBRARY SHEILA TERRY / SCIENCE PHOTO LIBRARY
Depending on the requirements the combustible ingredients of gunpowder, i.e., charcoal, saltpetre and sulphur, need to be reduced to a high-quality powder of a particular particle size. This 19th century French pilon ( 'pestle') powder mill was driven by a waterwheel and had a mechanical system that caused the rise and fall of the two pestles in the mortars full of the mixture to produce the powder. A rate of 55-60 pestle strokes was maintained for several hours. An alternative to the pilon mill was the water cylinder mill.
Model release not required. Property release not required.