Eraser is stationery made of rubber, which can erase traces of graphite or ink. There are many kinds of erasers, with different shapes and colors, including ordinary erasers, special erasers for art, such as 2B, 4B and 6B for painting, and plastic erasers.
People have been using erasers for more than 200 years now.
Eraser can erase pencil words, which was first discovered by British scientist Priestley in 1770. Before that, people used bread crumbs to erase pencil words.
Priestley's discovery caused a great sensation because it brought great convenience to people. However, the earliest erasers were made of natural rubber. When you erase the words, there is no crumb. It just sticks the pencil tip to the eraser, and the more it is rubbed, the dirtier it gets.
Later, when people made erasers, sulfur, oil and other substances were added to make the erasers easy to fall off, and the erased pencil scraps were left on the erasers together with the crumbs, so that the erasers could always be kept clean and the paper would not be stained.
Development history
In 1770, British scientist joseph priestley said, "I saw a substance that is very suitable for erasing pencil handwriting." At that time, the whole of Europe used rubber particles cut into small cubes to erase handwriting. This kind of rubber was called rubber.
EdwardNaime, another British engineer, is regarded as the inventor of the eraser in 1770. Before that, people used sponges to wipe away handwriting. Naime said that once he happened to pick up an eraser and found it to be very effective, so he began to produce and sell erasers.
The original eraser was inconvenient, because the unprocessed eraser was easy to rot. It was not until 1839 that the inventor CharlesGoodyear discovered that vulcanization could improve the quality of rubber, and the eraser became reliable.
1858, a man in Philadelphia, USA, obtained a patent for embedding an eraser at the end of a pencil, but later the patent for this pencil with an eraser was cancelled because it was judged as "just embedding two existing things together, not a new product".