02.10 Module 02 Review

Be able to list and describe the 3 main tools used to measure latitude in early navigation. dsssssssssssssssssssssssssssssssssssssssssssssssssssssssssss- ssssssssssssssssssssssssssssssssssssssssssssssssssfjjjjjjjjj- jjjjjjjjjjjjjjjjjjjjfffffffffffffffffffffffffffffffffffnnnnn- nnnnnnnnnnnnnnnnnnnnnnnnnn waves.jpg (26210 bytes) Heeding the flightpaths of birds was just one of numerous haven-finding methods employed by the Polynesians, whose navigational feats arguably have never been surpassed. The Polynesians traveled over thousands of miles of trackless ocean to people remote islands throughout the southern Pacific. Modern navigators still scratch their heads in amazement at their accomplishment. Like Eskimos study the snow, the Polynesians watched the waves, whose direction and type relinquished useful navigational secrets. They followed the faint gleam cast on the horizon by tiny islets still out of sight below the rim of the world. Seafarers of the Marshall Islands built elaborate maps out of palm twigs and cowrie shells. These ingenious charts, which exist today only in museums, denoted everything from the position of islands to the prevailing direction of the swell. ptolemy.jpg (28650 bytes) Statue of Ptolemy.

Charts have aided mariners ever since the Alexandrian astronomer Ptolemy created the first world atlas in the second century A.D. The redoubtable Ptolemy even plotted latitude and longitude lines on his atlas's 27 maps, though the farther one got from the known world centered on the Mediterranean, the dangerously less reliable they became. Even before Ptolemy, there were sailing directions -- the Greeks called them periplus or "circumnavigation" -- that were compiled from information collected from sailors far and wide. One of these, The Periplus of the Eritrean Sea, a document written in the first century by a Greek merchant living in Alexandria, described trading routes as far east as India. By the 10th century, Italian-made portolans supplied