Braille

Braille (/breɪl/; French: ) is a tactile writing system used by people who are visually impaired. It is traditionally written with embossed paper. Braille users can read computer screens and other electronic supports using refreshable braille displays. They can write braille with the original slate and stylus or type it on a braille writer, such as a portable braille notetaker or computer that prints with a braille embosser. Braille literacy is a social-justice issue. Early braille education is crucial to literacy, education and employment among the blind. However, in the face of changes in education policy and screen reader software, braille usage has declined in recent decades, despite the fact that technologies such as braille displays have also made braille more accessible and practical. Braille is named after its creator, Louis Braille, a Frenchman who lost his sight as a result of a childhood accident. In 1824, at the age of fifteen, he developed a code for the French alphabet as an improvement on night writing. He published his system, which subsequently included musical notation, in 1829. The second revision, published in 1837, was the first small binary form of writing developed in the modern era. These characters have rectangular blocks called cells that have tiny bumps called raised dots. The number and arrangement of these dots distinguish one character from another. Since the various braille alphabets originated as transcription codes for printed writing, the mappings (sets of character designations) vary from language to language, and even within one; in English Braille there are three levels of encoding: Grade 1 – a letter-by-letter transcription used for basic literacy; Grade 2 – an addition of abbreviations and contractions; and Grade 3 – various non-standardized personal stenography. Braille cells are not the only thing to appear in braille text. There may be embossed illustrations and graphs, with the lines either solid or made of series of dots, arrows, bullets that are larger than braille dots, etc. A full braille cell includes six raised dots arranged in two columns, each column having three dots. The dot positions are identified by numbers from one to six. There are 64 possible combinations, including no dots at all for a word space. A cell can be used to represent a letter, digit, punctuation mark, or even a word. Braille was based on a tactile military code called night writing, developed by Charles Barbier in response to Napoleon's demand for a means for soldiers to communicate silently at night and without a light source. In Barbier's system, sets of 12 embossed dots encoded 36 different sounds. It proved to be too difficult for soldiers to recognize by touch and was rejected by the military. In 1821 Barbier visited the Royal Institute for the Blind in Paris, where he met Louis Braille. Braille identified two major defects of the code: first, by representing only sounds, the code was unable to render the orthography of the words; second, the human finger could not encompass the whole 12-dot symbol without moving, and so could not move rapidly from one symbol to another. Braille's solution was to use 6-dot cells and to assign a specific pattern to each letter of the alphabet.At first, Braille was a one-to-one transliteration of French orthography, but soon various abbreviations, contractions, and even logograms were developed, creating a system much more like shorthand. The expanded English system, called Grade-2 Braille, was completed by 1905. For blind readers, Braille is an independent writing system, rather than a code of printed orthography. Braille is derived from the Latin alphabet, albeit indirectly. In Braille's original system, the dot patterns were assigned to letters according to their position within the alphabetic order of the French alphabet, with accented letters and w sorted at the end. The first ten letters of the alphabet, a–j, use the upper four dot positions: ⠁⠃⠉⠙⠑⠋⠛⠓⠊⠚ (black dots in the table below). These stand for the ten digits 1–9 and 0 in a system parallel to Hebrew gematria and Greek isopsephy. (Though the dots are assigned in no obvious order, the cells with the fewest dots are assigned to the first three letters (and lowest digits), abc = 123 (⠁⠃⠉), and to the three vowels in this part of the alphabet, aei (⠁⠑⠊), whereas the even digits, 4, 6, 8, 0 (⠙⠋⠓⠚), are corners/right angles.)