सेमफोरे

From Wikipedia, the free encyclopedia:

The semaphore or optical telegraph is an apparatus for conveying information by means of visual signals, with towers with pivoting blades or paddles, shutters, in a matrix, or hand-held flags etc। Information is encoded by the position of the mechanical elements; it is read when the blade or flag is in a fixed position। In modern usage it refers to a system of signaling using two handheld flags।


http://www।nytimes।com/2006/11/21/arts/21sema.html