This cap badge was worn by Thomas Leslie upon his promotion to the rank of principal keeper in 1953. Principal keepers would usually need to have served about 15 years before their promotion from assistant to principal. The entire service worked by dead man's shoes - a rank of seniority based entirely on your start date. A Principal Keeper had overall responsibility for their lighthouse on a day-to-day basis. Mr Leslie served as PLK at Killantringan, Douglas Head, Mull of Kintyre and then Kinnaird Head from where he retired in 1972.