A bone crusher is a device regularly used for crushing animal bones. Bones obtained during slaughter are cleaned, boiled in water and dried for several months. After that, they are suitable for crushing with the special machine into a relatively dry gritty powder which is used as fertilizer.
The machine, shown in the picture, is powered by a
water wheel
A water wheel is a machine for converting the kinetic energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a large wheel (usually constructed from wood or metal), with numerous b ...
. It contains eight S-shaped pairs of cams that raise the crushers alternately and let them fall into material to be crushed. The simple transmission increases the rotation speed of the crusher wheel to 21 rpm from the water wheel speed of about 7 rpm.
Bone meal
Bone meal (or bonemeal) is a mixture of finely and coarsely ground animal bones and slaughter-house waste products. It is used as a dietary supplement to supply calcium and phosphorus to monogastric livestock in the form of hydroxyapatite. As a slo ...
has been used since about 1790 as a fertilizer supplement to ordinary farmyard manure. From about 1880 onwards it was supplanted by chemical fertilizers.
See also
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Stamp mill
A stamp mill (or stamp battery or stamping mill) is a type of Mill (grinding), mill machine that crushes material by pounding rather than Mill (grinding), grinding, either for further processing or for extraction of metallic ores. Breaking materia ...
, a similar machine used to crush ore in mining situations.
References
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Grinding mills