• Hakkında.
  • ilk kalemi kim icat etti ingilizce olarak

    Invention of the Pencil
    The “lead” pencil (which contains no lead) was invented in 1564 when a huge graphite (black carbon) mine was discovered in Borrowdale, Cumbria, England. The pure graphite was sawn into sheets and then cut into square rods. The graphite rods were inserted into hand-carved wooden holders, forming pencils. They were called lead pencils by mistake – at the time, the newly-discovered graphite was called black lead or “plumbago,” from the Latin word for lead ore – it looked and acted like lead, and it was not known at the time that graphite consisted of carbon and not lead. The English had a monopoly on the production of pencils since no other pure graphite mines were known and no one had yet found a way to make graphite sticks.

    The Germans manufactured graphite sticks (made from powdered graphite), but they were impractical. In 1795, the Nicholas Jacques Conte (a French officer in Napoleon’s army) patented the modern method of kiln-firing powdered graphite with clay to make graphite rods fro pencils. By varying the ratio of graphite to clay, the hardness of the graphite can also vary.

    Before themid-1500s, “pencils” consisted of a thin rod composed of soft lead, and were used mostly by artists. The word pencil comes from the Latin word “penicillus,” which means “little tail” – the name of the tiny brush that ancient Romans used as a writing instrument. Graphite (named for the Greek word meaning “to write”) was chemically analyzed in 1779 (by K.W. Scheele) and named in 1789 (by A.G. Werner).


    kalemin icadı ingilizce