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Time passed. In 1794 French scientist and inventor Nicola Jacques Conte invented first modern pencil. Parliament of England in the end of XVIII century prohibited slate exports from Kamberland county, otherwise violators could be punished to death. Nevertheless, slate smuggling delivered гit to continental Europe that lead to rise in prices. So Convent of France ordered Conte to elaborate technology of combining powdered slate, clay, farina, smut and water in order to produce high-quality holder. Due to high-temperature processing real hardness was achieved, change in proportions allowed to produce holders of various hardness, that is now the basis of pencil hardness classification.
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