Bosuns are known to have used whistles from the earliest times, primarily for giving directions to sailors aloft, but later for "piping aboard" high-ranking naval officers and important visitors. By the mid-18th century, silver examples were made, but examples dating from before 1800 are extremely rare. It is interesting to note that the present example follows the form that was to become standard by the 19th century, the pipe known as the "gun" and the barrel as the "buoy" and the flat plate between them as the "keel" (Michael Clayton, The Collector's Dictionary of the Gold and Silver of Great Britain and North America, 1985, p.40).