A large deposit of graphite was discovered in 1565 on the approach to Grey Knotts from the hamlet of Seathwaite in Borrowdale parish, Cumbria, England. This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. It remains the only large-scale deposit of graphite ever found in this solid form. Chemistry was in its infancy and the substance was thought to be a form of lead. Consequently, it was called plumbago. Because the pencil core is still referred to as "lead", or a "lead", many people have the misconception that the graphite in the pencil is lead, and the black core of pencils is still referred to as lead, even though it never contained the element lead. The words for pencil in German, Irish, Arabic, and some other languages literally mean lead pen. The value of graphite would soon be realised to be enormous, mainly because it could be used to line the moulds for cannonballs; the mines were taken over by the Crown and were guarded. When sufficient stores of graphite had been accumulated, the mines were flooded to prevent theft until more was required. Graphite sticks were initially wrapped in string or sheepskin for stability. England would enjoy a monopoly on the production of pencils until a method of reconstituting the graphite powder was found in 1662 in Italy. However, the distinctively square English pencils continued to be made with sticks cut from natural graphite into the 1860s. The town of Keswick, near the original findings of block graphite, still manufactures pencils, the factory also being the location of the Cumberland Pencil Museum.
Production technology has changed little over the past120 years. Only standards and mechanisms for the manufacture of rods and wooden halves were improved. The main components in the manufacture of rods - purified graphite powder and kaolin. Hardness depends on the ratio of their particles. The more graphite - the softer the rod. The hardest pencil contains about 20% graphite, the softest one up to 90%. The 1:1 ratio roughly corresponds to the 3H hardness. The sequence of operations for the manufacture of graphite rods:
