|Source : Wikipedia|
The Braille system, named after Louis Braille, is a method that is widely used by blind people to read and write. Each Braille character or "cell" is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four combinations, counting the space, in which no dots are raised. For reference purposes, a particular combination may be described by naming the positions where dots are raised, the positions being universally numbered 1 through 3 from top to bottom on the left, and 4 through 6 from top to bottom on the right. For example, dots 1-3-4 woulddescribe a cell with three dots raised, at the top and bottom in the left column and on top of the right column.
The Braille system was based on a method of communication originally developed by Charles Barbier in response to Napoleon's demand for a code that soldiers could use to communicate silently and without light at night called night writing. Barbier's system was too complex for soldiers to learn, and was rejected by the military; in 1821 he visited the National Institute for the Blind in Paris, France, where he met Louis Braille. Louis identified the major failing of the code, which was that the human finger could not encompass the whole symbol without moving, and so could not move rapidly from one symbol to another. His modification was to use a 6 dot cell - the Braille system - which revolutionized written communication for the blind.
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