In 1795, a man named Comte invented a pencil made of a mixture of graphite and some sorts of clays which were burnt in the furnace. "Simple" pencils are made of graphite, which leaves a dark trail on paper. In the process of pencil manufacturing, dry graphite powder is mixed with clay and water. The more clay there is, the harder the pencil and the more graphite, the softer is the pencil. Wood billets of cedar or pine are cut in half alongside and a groove is cut out for the lead. Both halves of the pencil are then glued together. The billets are cut into pencils whose surface is polished. Today more than 300 different kinds of pencils are produced for various purposes. There are pencils for writing and leaving trace on such surfaces as glass, fabric, cellophane, celluloid and plastic, which are used in construction .
Marie-Great! I have read the story but I haven't seen the play yet. Paul- I saw it on TV some days ago and I liked it Melanie- I got a Hansel and Gretel film and I had been watching it for an hour yesterday evening. Paul- Yesterday we went with our geography teacher to the Natural History Museum. We had been doing geography tasks and studying dinosaurs for two hours.Have you been to the Natural History Museum yet? Marc- No, we haven't Paul- You should see the dinosaurs. Why not go to the museum on Sunday together? Marc- That's great!
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