## Bearings in the field

Now the magnetic needle gets to do its job. All bearings in the field are based on where the needle points. For the sake of simplicity in these first two examples, wc will ignore the effects of magnetic declination, a subject that will be taken up in the next section. Let's imagine we are taking the bearings in Ohio, which happens to be along the line of zero declination.

ALIGN MAGNETIC NEEDLE WITH ORIENTING ARROW

Fig. 4-8. Taking a compass bearing in the field in an area with zero declination

ALIGN MAGNETIC NEEDLE WITH ORIENTING ARROW

Fig. 4-8. Taking a compass bearing in the field in an area with zero declination

To take (measure) a bearing in the field: Hold the compass in front of you and point the direction-of-travel line at the object whose bearing you want to find. Rotate the compass housing until the pointed end of the orienting arrow is aligned with the north-seeking end of the needle. Read the bearing at the index line (fig. 4-8). And that's all there is to it.

If the compass has no sighting mirror, hold it at or near ami's length and at or near waist level. With a sighting mirror, hold the compass at eye level with the sight pointing at the object. Observe the magnetic needle and the orienting arrow in the mirror as you rotate the housing to align the needle and the arrow. In either case, hold the compass level. Keep it away from ferrous metal objects, which can easily deflect the magnetic needle.

To plot (follow) a bearing in the field: Simply reverse the process used to take a bearing. Start by rotating the compass housing until you have set a desired bearing at the index line, say 270 degrees (due west). Hold the compass level in front of you and then turn your entire body until the north-seeking end of the magnetic needle is aligned with the pointed end of the orienting arrow. The direction-of-travel line is now pointing due west. And that's all there is to that.