Question 606Navigation General

The correct answer is D) mercury ballistic. The system of reservoirs and connecting tubes in a gyro compass is called the mercury ballistic. This is because the gyro compass uses a mercury-filled bowl as part of its stabilization mechanism, with the mercury flowing through a series of interconnected reservoirs and tubes to dampen the movement of the compass. The other answer choices are incorrect because they do not accurately describe the specific components of a gyro compass. A gyrotron is not a term associated with gyro compasses, a spider element refers to a different part of the compass, and a rotor is a component of a different type of navigation instrument.