00 What is the Pasley Telegraph?

Due to the susceptibility of Sir Home Popham’s design to failure, Charles William Pasley proposed a further development in 1823.

Description of the universal telegraph, for day and night signals – sir Charles William Pasley – Google Books

The system also consisted of one mast, but the two wing arms were mounted together at the top of the mast.

The system was used until the 20th century – most recently for communication with the Isle of Wright and the canal forts.

https://www.royal-signals.org.uk/Datasheets/Telegraph.php