In the U.S., the angle of declination varies from about 20 degrees west in Maine to about 21 degrees east in Washington. (See Figure 6.7). The magnetic field lines of the earth are constantly changing ...

If your compass does not have adjustable declination, you will need to add or subtract the number of degrees manually each time you take a bearing. Step 2: Line up your orienting line with your ...

I prefer not to use it and teach our students the same. It aids in adjusting declination, which we will cover later. Index Line: This immovable line lies directly beneath the compass dial.