Complex sentence: In 1821, he proposed a telegraphy system utilizing a one wire per "galvanometer" to indicate each letter, and reported experimenting successfully with such a system, however in 1824, Peter Barlow reported its maximum distance was only 200 feet, so was impractical.
Split into simpler sentences: In 1821, he proposed a telegraphy system utilizing one wire per "galvanometer" to indicate each letter, and reported experimenting successfully with such a system. However, in 1824, Peter Barlow reported its maximum distance was only 200 feet, and so was impractical.