before the invention of the timepiece was fairly complex. Explorers
and Navigators of the Age of Exploration used a wide variety of
tools to sail from point to point.
The Magnetic compass was probably the most
revolutionary invention of the second millenium, however, it is
impossible to say exactly where and when it was invented. Almost
every culture has tried to lay claim to its existence.
The windrose developed over the turn of
the first millenium, and then evolved parallel to the magnetic
compass; eventually the two were combined as the Compass Rose.
Astrolabes have been in existence for thousands
of years, however their development was as a tool of Astrology,
so often times they are better suited for telling fortunes than
A Jacob's Staff was used to measure the
angle of the Sun from the horizon, however it required the user
to stare into the Sun's blinding rays: the Back Staff was invented
to correct this design flaw.
The main problem with the absense of an
accurate time measurement device was longitude. Longitude is measured
in hours, and the best way to measure distance horizontally on
a continuously rotating sphere is by time. Observers of the 15th
century knew that the Sun predictably traveled overhead, but they
had no accurate and absolute way to measure the time. Many of
the tools made before the 17th century were actually shortucts
to measuring time. These tools eventually culminated in the sucessful
development of a time measuring device.