"Pacific island societies used an upside-down triangular sail, attached to a single vertical pole."
Thomson Gale, The World of Invention (2006)
For thousands of years sails have been used to harness the wind. By 3500 B.C.E., ancient Egyptian vessels were being blown up the Nile by the prevailing wind before returning under oars, and the Phoenicians pioneered the development of hardier vessels for sea voyages. However, these vessels used square-rigged sails to catch the wind and carry them along with it. In order to progress into the wind the sail must instead be used as an aerofoil to produce a lifting force perpendicular to the wind passing over it. The sail can be angled toward the wind and a component of the lift force generated gives forward thrust to the vessel, thus allowing modern craft to sail within a few degrees of the very direction from which the wind is blowing,
Sails were employed in this way in the Arabian Sea in 300 C.E., but further developments were minor until the fifteenth century and the advent of the European full-rigged vessel. This bore multiple masts hung with both triangular and square sails, providing maneuverability as well as stability and power.
Commercial sailing peaked in the nineteenth century with the emergence of the Americas as competition in trade. Speed and size were paramount, characterized by clippers traveling at up to 20 knots (37 km/h) from China, North America, and Australia, and by vast full-riggers powered around Cape Horn by more than an acre (0.4 ha) of sail area.
