Complex sentence: Byam took up philately in 1923 as a method of relaxation from his stressful medical practice and joined the Royal Philatelic Society London (RPSL) in 1924.
Split into simpler sentences: Byam took up philately in 1923 as a method of relaxation from his stressful medical practice. He joined the Royal Philatelic Society London (RPSL) in 1924.