Write an essay on "Braille system".

The most popular resource for visually challenged persons is known as Braille. Louis Braille, himself a blind person, developed a system for visually challenged persons and published in 1821. The present system was adopted in 1932. There is Braille code for common languages, mathematics, and scientific notation. Indian languages such as Hindi, Sanskrit, Marathi, Gujarati, Bengali, Tamil, Telugu and Urdu, can be read using the Braille system Braille system has 63 dot patterns or characters. Each character represents a letter combination of letters, common word or grammatical sign.Visually challenged people learn the above system by beginning with letters and then to special characters and letter combinations. Methods depend upon recognition by touching. Each character has to be memorised. Braille texts can be produced by hand or by machine. To write Braille by hands, a slate is used consisting to two metal plates hinged together with paper in between them. A writer inserts a stylus to make dot patterns through a cell size opening on the upper plate. Type writer like devices and printing machines which use enclosed zinc plates to make coded impressions on paper, have also been developed.