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Turn the dial to increase or decrease that reading according to the declination.
Easterly, decrease the dial reading and westerly, increase the reading.
For example, if your bearing from the map is l00º and the declination is 10º East,
DECREASE the reading 10º by turning the dial to 90º. If the declination is 10º
West, INCREASE the reading of l00º to read 110º.
2.
Permanent Method. Your compass is equipped with an offsetting mechanism to
allow for declination. If you use the compass extensively in one locality, once set,
you need not make further allowances. The adjustment simultaneously takes care
of both map bearings and field bearings.
The offsetting mechanism consists of two bottoms in the compass dial housing,
one of which can be offset in relation to the other by means of a declination
adjusting screw located on the underside of the base plate. The orienting lines
and the declination scale are engraved on one bottom. The orienting arrow
and the orienting points are on the other. As you turn the adjusting screw you
change the angle between the orienting lines and the orienting arrow. It is this
angle that should correspond to the declination of your area. A screwdriver, pro-
vided for this purpose, is tied onto the lanyard.
For example, if the declination in your area is 10º west, turn the adjusting screw
so that the orienting arrow points to 10º on the “west” side of the declination
scale. If your declination is 10º east, adjust the orienting arrow to 10º on the
“east” side of the declination scale. Use the black index line of the orienting
arrow to make an accurate setting.
