Page 132 - 4670

2. A compass rose.
3. Different fields of compass application.
4. The main ways of compass usage.

Compasses: their types and functions.

Direction as well as location is very important for orientation. The
most common way to describe direction in relation to the Earth’s

surface is by using a compass. A compass is an instrument containing
a freely suspended magnetic element (a floating needle) which
displays the direction of the horizontal component of the Earth’s
magnetic field at the point of observation.

Figure 9.4. A floating needle of a compass

A compass needle aligns to the Earth’s magnetic North Pole, not
the Earth’s geographic North Pole or true north. The geographic North

Pole is the top of the imaginary axis upon which the Earth’s rotates,
much like the spindle of a spinning top. The magnetic North Pole
shifts in location over time. Depending on where you live, you can

correct for this difference when you use a map and a compass.
Once you find north, you can then describe any other direction,
such as east, south, west, etc., on a compass rose.

132