
The
M2 compass, is a multiple purpose instrument applicable to obtaining
clinometer, angle of site, and azimuth readings. The body of the
compass is dust proof and moisture proof, and is made of nonmagnetic
material except for the magnetic needle and its pivot. When the cover
is closed, the magnetic needle is automatic ally lifted from its pivot
to protect the pivot point and jewel bearing. The jewel bearing is
agate. The compass is provided with an angle of site scale and an
azimuth scale. The azimuth scale may be rotated approximately 1, 800
roils. The compass is equipped with circular and tubular levels. In
place of a telescope, the compass employs front and rear leaf sights in
conjunction with a mirror in the cover for sighting and reading the
angles. The instrument has an azimuth scale adjuster for orienting the
azimuth scale to the local magnetic declination, so that grid or Y
azimuths may be read direct.