TM 9-1290-357-15
provides a magnetic north direction for orienting
desired. The tube has a spindle socket assembly
purposes. The needle is delicately balanced and
for seating the spindle and forming a ball and
jewel mounted on a pivot to rotate freely. The
socket joint for leveling aiming circle M1. The
north end of the needle is read against an ad-
spindle is clamped in the socket by turning the
justable index, and the south end is read against
socket clamping screw.
a vertical center line, etched on an adjustable
needle reticle. The needle can be locked by pushing
contained lighting device used for illuminating
the red colored locking plunger button, and re-
the telescope reticle and for general illumination
leased by pushing the olive drab releasing
of the circle M1. A flashlight type dry cell battery
plunger button.
(which is installed in light's battery case when
Note. Detent actions insure that the needle is either in
used) furnishes current to electric lamps through
the clamped position (locked) or fully released.
two flexible cords. These cords carry current;
one to a lamp bracket assembly and the other
to a hand light assembly. The power to these
lamps is controlled by an "on" and "off" toggle
the needle reticle and the etched line on the south
switch. A thumb nut assembly secures the in-
end of the needle.
strument light to the tripod legs, and the hand
light assembly is secured to a clip on the battery
1-7. Equipment Issued with Aiming Circle,
case.
M1
The equipment issued with the aiming circle M1
to cover the aiming circle M1.
are listed and described in a through d below.
storing the aiming circle M1, w/e and transport-
legs, that can be clamped at the desired height.
ing purposes.
The legs are pivoted on a tripod head through
hinges that are adjustable, providing a tight
1-8. Tabulated Data
friction fit. A support tube that passes through
the tripod head may be clamped to the height
a. Optical Characteristics.
1-5
