Encyclopedia of society and culture in the ancient world ( PDFDrive ) 1055

960 seafaring and navigation: The Americas passengers or, as was more common, sold them into slavery Indeed, until the middle of the first century b.c.e., pirates were one of the chief sources of slaves for the Roman world Important captives, particularly high-ranking Roman citizens, were held for ransom Even Julius Caesar was a captive of pirates The pirate menace was ended in 67 b.c.e., when the Roman general Pompey swept the Mediterranean free of them Pirates would not again be a threat until the empire began to lose control of the seaways in the third century c.e Navigating a Roman ship was more art than science, since the Romans had no navigational instruments As a consequence, whenever possible, a ship of the period kept the shore in sight, its crew watching for landmarks to tell them their position An important aid to navigation was the lighthouse Most major Mediterranean ports had such structures, the Pharos at Alexandria being the most famous Lighthouses ranged in height from four to 12 stories and used a mirror of polished bronze to reflect light from a fire The beacon would warn night-traveling ships of hidden rocks and shallow water or act as a guide into port In addition to landmarks and lighthouses, Roman crews often depended on changing water depths to tell them where they were, since specific locations along a coast had known depths To measure the depth of water, mariners used a lead line This line was a rope that had a series of knots at spaced intervals and that had a lead or stone weight tied to it The weighted end of the line was tossed overboard, and when it hit bottom, the number of knots were counted to determine the depth Another piece of knowledge useful in Roman navigation was the composition of the sea bottom across which a ship was sailing That composition could often provide a clue as to a ship’s location because certain types of material—gravel, sand, or mud, for instance—were known to be present off certain coastlines Roman mariners sampled the sea bottom with the lead line, whose weight had a depression fi lled with tallow, or animal fat, to which sea floor material stuck then to be drawn up to the surface The Romans probably had charts and certainly had periploi, books containing the distances between various seaports, along with the locations of rivers and freshwater sources A ship’s navigator could calculate his ship’s position along its route using the distances given by a periplus if he knew how far his vessel had traveled during a day He made this calculation using dead reckoning He first had to determine how fast his ship was traveling The navigator estimated this speed by observing seaweed or drift wood passing by the ship This observation gave him an approximation of how much distance the ship covered in an hour Then, at the end of a day’s sail, based on his observed speed, the navigator calculated how far the vessel had traveled He now had a rough idea of where along its route the ship was The method was imprecise, and often the calculation was far off the mark Determining position by dead reckoning also required that the navigator know in which direction his vessel was headed; otherwise, the craft might be sailing away from its destination During the day the navigators determined direction by observing the sun Sailing into it was going west; sailing away from it was going east Additionally, the navigator knew the ship was going north or south depending on the sun’s height above the horizon at noon The sun would be higher or lower in the sky depending on whether a ship was headed north or south The height of the sun also depends on the time of year, the sun rising higher in the summer than in the winter, but an experienced navigator took this fact into account To measure the sun’s height, the navigator would hold out a hand and determine how many fingers were needed to span the gap between the sun and the horizon At night the navigator established direction using the stars One star—the polestar, or Polaris—was particularly useful since it marks the position of the North Pole and remains fi xed throughout the night (Other stars appear to revolve around the sky due to the rotation of the earth.) A ship traveling east would have the polestar on its right, and a ship traveling west would have the polestar on its left A navigator could also obtain a rough idea of a ship’s north-south position using the polestar by counting how many fingers were needed to span the gap between Polaris and the northern horizon The fewer the fingers, the farther south the ship was since in moving south, Polaris drops toward the northern horizon THE AMERICAS BY LAWRENCE WALDRON Native American hunters have long been credited with possessing the most acute tracking skills Their ability to observe signs on the earth, in the air, and in the movements of animals and birds has astounded many observers There is no reason to assume that Native American seafarers were any different Just as earthbound hunters would observe the movement of celestial bodies to predict changes in weather, animal behavior, and crop growth, so too would Native Americans living on coasts, along rivers, and on arctic ice navigate by observing and predicting their environment Native Americans in ancient times were intimately familiar with the courses of key celestial bodies; the different kinds of cloud cover; the varieties of terrestrial, riverine, and marine species; and the flight patterns of birds They also would have possessed some knowledge of geology, though they would have employed taxonomic classifications and nomenclature very much unlike our own All these skills would have constituted the Native American navigation kit, necessary knowledge not only for achieving intended destinations and predictable travels but also for preserving self, family, and culture along the course of those travels Both on foot and by boat, Native Americans displayed great maneuverability and speed, due largely to their success as navigators, trackers, and aquatic farers The American continents from Alaska to Argentina appear to have been settled within a thousand years of the first arrival of