Bark (botany) rope, used for example in the rigging of Viking age longships. Among the commercial products made from bark are cork, cinnamon, quinine (from the bark of Cinchona) and aspirin (from the bark of willow trees). The bark of some trees notably oak ("Quercus robur") is a source of tannic acid, which is used in tanning. Bark chips generated as a by-product of lumber production are often used in bark mulch in western North America. Bark is important to the horticultural industry since in shredded form it is used for plants that do not thrive in ordinary soil, such as epiphytes.
Bark mill Bark mill Bark mills, also known as Catskill’s mills, were water, steam, horse, ox or wind-powered edge mills used to process the bark, roots, and branches of various tree species into a fine powder known as tanbark, used for tanning leather. This powdering allowed the tannin to be extracted more efficiently from its woody source material. A barker would strip the bark from trees so that it might be ground in such mills, and the dried bark was often stored in bark houses. Various machinery was used to chop, grind, riddle and pound the bark. These included Farcot’s bark-cutting machine,