Synchronous methods of operation for private telegraph networks

There are many private telegraph networks in the United States serving industrial, commercial, financial, and transportation organizations, and used for the transmission of intracompany message traffic, data transmission, and telemetering. In size there is a wide range, from small networks with a home office and a single branch, to large and highly complex ones with tens of thousands of miles of facilities, hundreds of operating points, and weekly message files running into six figures. The majority of private networks lease both equipment and facilities. However some own their operating equipment and lease facilities, while others own both equipment and the plant that provides the facilities.