Ans.—Currents are exchanged from earth to air and from planet to planet.
Ques.—Do these affect the mariner's compass?
Ans.—Yes.
Ques.—Can we control the local attraction of the compass?
Ans.—Yes.
Ques.—How? I exclaimed excitedly, as the thought flashed through my mind that I was on the eve of a great discovery.
Ans.—By the substitution of some other attractive force?
Ques.—Name one.
Ans.—Magnetized iron.[3]
Ques.—Can the compass be so constructed as to be uninfluenced by local attraction?