Parts of the Compass:
- Direction of Travel Arrow
- Housing or Bezel
- Orienting Arrow
- Declination Lines
- Magnetic Needle
A good compass has a base plate and a housing or bezel, the round part in the middle which rotates freely. Along the base plate of the compass you will sometimes have markings and graduations along the side. Some styles have a flip lid on it, some of those with a mirror in the back of that. It may also have a slit or a hole that’s cut in the lid that you can see through.
On the base plate itself you can see an arrow that’s called your direction of travel arrow. There may be one, two, or three. You should always point this the direction you intend to go.
On the bezel there’s markings on around the outside, usually in two degree increments of the 360 geometric degrees that surround you when you stand in one spot on the landscape. The cardinal directions are printed by first letter around the outside. Regardless, north is always 0 degrees, south is always 180 degrees, east is always 90 degrees, and west is always 270 degrees. Those degree readings never change.
If you grab the bezel and move that around, in the back you can see the outline of an arrow like an elongated house that moves with the bezel. That’s the orienting arrow. Usually this one is red, and it points to ’N’ for north.
Of course in the middle of the bezel you can see the free floating arrow on the spindle. That is the magnetic or magnetized needle, almost always red, that points to magnetic north. Magnetic north is an important distinction from geographic north. The only time this needle will not point at magnetic north is if it’s broken or thrown off by metal objects like a belt buckle or necklace, rebar in concrete or screws in a wooden deck. These can throw off the reading of your magnetic needle.
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