Перевести! нужно! about 5000 years ago, the egyptians first hoisted primitive sails to propel boat upstream against the nile current. from then until the middle of the 19th century, when clipper ships were racing the oceans, nearly all water transport relied on the direct force of the wind. the early sailing ships could travel only with-or at best at right angles to-the wind.then came triangular sails, probably an asian invention; they enabled ships to sail close to the wind and thereby more then doubled their usefulness. long ocean voyages were at last possible.