20,000 LEAGUES OVER THE BOUNDING main

LOG ENTRY XI It’s About Time The next steps in determining a ship’s location involved creating instruments that could accurately calculate angles between the horizon and celestial bodies. In the 1360’s, the astrolab (Greek, “astron,” meaning, “star,” and “lambanein,” meaning, “take (as a measurement),” was invented, which was simply a sky chart with a moveable sight to determine angles. Time passed, and in 1569, a Flemish geographer, Geraedus Mercator, created the “Mercator” map - a great additional aid to mariners. Time passed again, and in the 1600’s the astrolab was replaced by the octant (from Latin, “octans,” and “-antem,” implying, “to show),” an instrument that measured the position of one celestial body when it is 45 degrees (one-eighth of 360 degrees of a circle) from another. It took more time, until 1730, when two mathematicians and astronomers, John Hadley, an Englishman, and Thomas Godfrey, an American, developed the “sextant (Latin, “sextantis,” meaning “one-sixth of a circle).” in some cases, still used today. The first mariner to use it was Captain James Cook (1728-1779), an English naval officer, whose first exploration took him to Tahiti in 1769. In 1778, he became the first known European to reach the Hawaiian Islands, which he originally named the “Sandwich Islands,” in honor of an English nobleman named John Montagu, the 4th Earl of Sandwich, who, it is said did not want to leave a gaming table for a meal, so he ordered two pieces of bread with some meat between them. The original “sandwich!” However, although determining location based on angular measurements (aka degrees) north and south of the Equator was aided by the sextant, etc. known as “parallels of latitude”), it took “time,” in more than one sense, to establish, “meridians of longitude.” These “long” great circle lines are at right angles to the parallels of latitude and pass through the North and South Poles. The process of determining a longitudinal position starts with accurate timepieces, first developed in 1735 by John Harrison, an English clockmaker, who accurately determined longitude on a voyage from England to the Caribbean. However, it was obvious that, sooner or later (“timewise”), an international system for determining world-wide longitude would be necessary. Finally, in 1884, an international committee convened.