Download Navigational Tool Background

Navigational Tool Background
Astrolabe: The astrolabe is a navigational instrument which helps the Navigant’s at Sea to
find there Latitude. An astrolabe was often made of metal with a map of the stars and the
zodiac circle on the other side. The sun or a star showed a certain point on the astrolabe
which allowed the Navigator to determine the ships positions and during the day even the
time.
Cross-Staff: A cross-staff is inspired by the Kamal which was used by the Arab Navigators.
The cross-staff is made of a long staff normally 36 inches long and 4 smaller cross pieces
which move up and down the long staff. The navigator holds the cross-staff to the eye and
moves one of the four cross pieces forth and back until the two ends focus on the horizon
and a celestial’s body. The altitude he can read on the appropriate scale. The cross-staff is
much simpler than the astrolabe.
The table of declination: Is a navigational system similar to the longitude and latitude
system on earth. Declination is one of two coordinates. Therefore you imagine the space is
as round as the earth. The second coordinator is either the right ascension or an hour angle.
Declination is measured in degrees, north or south of the celestial equator. That means the
equator has a declination of O degree, the north pole a declination of plus 90 degrees and
the south pole a declination of minus 90 degrees.
Since you can use the solar system as well as stars to determine your position explorers
invented a so called table of declination of the sun, which includes the average of a leap
circle over four years. The solar system is much more changing over the years due to earth
rotation and the several seasons of the year.
The stars are much more fixed and lie nearly always in the same constant direction when
viewed from the earth.
All these navigational tools should allow me to make my journey as fast as possible and
find the Spicy Islands .
Compass: A compass is an instrument to navigate based on the magnetic poles, the North
Pole and the South Pole. Wherever you are the compass shows you the direction toward the
pole. On the surface of the compass you find the cardinal points of the magnetic field like
North, South, East and West. Often Compasses are build with a magnetized bar or needle
turning freely to point in the Northern or Southern direction. Together used with a other
navigational tools you can determine your longitude and latitude at sea.
Image of a Compass