The Bosun's, or boatswain's Whistle, is one of the oldest pieces of nautical equipment. It is the 'modern day' descendant of the flutes used by the Ancient Greeks and Romans to convey orders to the oarsmen and galley slaves. The first use of the whistle in the English Navy was during the crusades of the 13th century
The whistle is named after the Bosun -- a warrant or petty officer in charge of a ship's rigging, anchors, cables, and deck crew -- Bosun also being one of the oldest titles in seafaring history. The whistle was the Bosun's badge of office, and was often worn around his neck by a chain, and was used to "pipe" his to orders to the crew ("piping" is the naval method of passing orders).
In the days of sailing ships, verbal commands were often misunderstood -- or not heard at all above the the howling winds and the roaring seas. However, orders issued by the shrill tone of the Bosun's pipe could be heard above even the worst of gales. Today, the Bosun's whistle is still used to pipe the Captain or special visitors on board.
The parts of the whistle are as follows:The Gun - a tube section that you blow into approx. 10cm long
The Bouy - a hollow ball, with a hole in it
The Keel - a solid sction that you hold the whistle by, and holds the gun aligned with the hole in the bouy. There is also a shackle to hang a chain off in the keel.
There are two main notes the pipe can play, the "Low" and the "High", and there are three tunes; the "Plain", the "Warble", and the "Trill".
The "Plain low" note is produced by blowing steadily into the mouth of the gun, with the hole in the buoy unobstructed by the fingers.
The "Plain high" note is produced by throttling the exit of air from the hole of the buoy;
by closing the fingers around the buoy, taking care not to touch the edges of the hole or the end of the gun. Intermediate notes can be obtained by throttling to a greater or lesser degree.
The "Warble" ins produced by blowing a series of jerks, which results in a warble similar to that of a canary.
The "Trill" is produced by vibrating the tongue while blowing, as in rolling the letter "RRRR".