SILVA is the leading quality compass manufacturer in the
world, producing approximately 2 million compasses per year in Sweden. The expertise of SILVA is based on unique
knowledge, gained through more than 70 years of invention, testing and
refinement of navigation equipment of the very highest quality. Leading edge
technology and top professional management bring all the operations
together. This means that projects are completely controlled by SILVA, from
the drawing board, through production to marketing.
Taking a
bearing from the map. The SILVA 1-2-3 SYSTEM:
1. Place the compass on the map with the edge of the compass along the
desired line of travel.
2. Rotate the compass housing until N on the dial points North on the
map. Check that the compass housing red/black north/south lines are parallel
with the maps meridians.
3. Hold the compass in your hand and turn yourself until the red end of
the compass needle (North) points to the magnetic variation (somewhere
between 18˚ - 25˚ for New Zealand depending on where you are*) on the
adjustable dial. The front of the compass with the direction of travel arrow
is now pointing towards your destination.
* Note: For
general use a line can be marked on the dial between 20˚ (easily remembered
and sufficiently accurate for most purposes) and the pivot to make it easier
to keep the needle in the right position. On some of the Silva range you can
set an adjustable indicator line to the variation.
Compass-speak:
Magnetic North
vs. True North
A compass points
towards magnetic north, but this is not the same as true north.
Sound confusing? Magnetic north is the direction the needle of the compass
points to. This direction is based on the magnetic fields of the earth and
is not the same as true north, which is the geographic north or toward the
North Pole. In New Zealand magnetic north is actually around 23º east of
true north (varies from one end of the country to the other). This is known
as magnetic declination.
Global Magnetic
Regions:
Because of the
Earth’s curvature and variances in the Earth’s magnetic field, a compass
designed for the northern hemisphere will ‘stick’ in the southern
hemisphere, as it will basically be trying to point towards the ground.
The image to the
left shows the 5 magnetic zones the compass industry has defined. Depending
where in the world you are any standard compass you purchase generally has
its needle balanced only for that region. e.g: most compasses sold in New
Zealand will only be most effective in New Zealand and Australia.
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