Input (grade 13): Prior uses of water wheels include milling flour in gristmills and grinding wood into pulp for paper making, but other uses include foundry work and machining, and pounding linen for use in the manufacture of paper.
Output (grade 12): The most common use of the water wheel was to mill flour in gristmills, but other uses included foundry work and machining, and pounding linen for use in paper.