The Board of the Port of Liverpool obtained a Private Act of Parliament to construct a chain of Popham optical semaphore stations from Liverpool to Holyhead in 1825. The system was designed and part-owned by Barnard L. Watson, a reserve marine officer, and came into service in 1827. The line is possibly the only example of an optical telegraph built entirely for commercial purposes. It was used so that observers at Holyhead could report incoming ships to the Port of Liverpool and trading could begin in the cargo being carried before the ship docked. The line was kept in operation until 1860 when a railway line and associated electrical telegraph made it redundant. Many of the prominences on which the towers were built ('telegraph hills') are known as Telegraph Hill to this day.