Gunners Quadrant M1 with Case and Technical Manual, 1943 WW1 of the guns needed to

of the guns needed to be trained (turned) left or right

25 inches diameter and ~2

two aluminum drift plates that screw onto the base plate

From FLIGHT Magazine April 1954 PPs 390-391

and the front page of the Collins sales brochure

Gunners Quadrant M1 with Case and Technical Manual, 1943 WW1 of the guns needed toThis is a WWII era M1 Gunners Quadrant, a portable precision leveling instrument used for laying artillery weapons in elevation, measuring their angles of elevation, and checking the elevation mechanisms of fire control equipment. The Gunners Quadrant was also used to level the guns of aircraft such as the B 29 Superfortress and to harmonize the guns with their gun sights. See image of page 67 from the B 29 Gunnery Manual describing the Quadrant. The