Roller furling headsail
A general term for jibs or headsails which can be rolled around their own Luffs, whether for reefing or just for furling. The first, using a wooden Luff spare turning on a wire threaded through its length, was introduced by Captain du Boulay in 1887. Modern versions of the same idea use an aluminium alloy spar. Both these kinds may be used for reefing – that’s to say with the sail partially deployed. The all-or-nothing furling gears have wire at the luff, as in the Wykeham Martin gear.