TELEGRAPH (Gr. Tike, far, and rypaq5eiv, to write)  , the name given to an apparatus for the transmission of intelligence to a distance . Etymologically the word implies that the messages are written, but its earliest use was of appliances that depended on visual signals, such as the semaphore or optical telegraph of Claude Chappe . The word is still some-times employed in this sense, as of the ship's telegraph, by means of which orders are mechanically transmitted from the navigating bridge to the engine room, but when used without qualification it usually denotes telegraphic apparatus worked by electricity, whether the signals that express the words of the message are visual, auditory or written . Land and Submarine Telegraphy will be considered in Part I., with a section on the commercial aspects . In Part II . Wireless Telegraphy is dealt with .