It gave the first rational explanation to the mysterious ability of the compass needle to point north-south: the Earth itself was magnetic.
(the Earth; was; magnetic) Context(the Earth was,List([109, 129))):(It; gave; the first rational explanation to the mysterious ability of the compass needle)
the Earth was,List([109, 129))
the Earth It
was gave
magnetic
the first rational explanation to the mysterious ability of the compass needle