The fact that the grains of ancient rocks are lined up like tiny compass needles has led to the astonishing conclusion that the earth's magnetic poles have wandered and reversed By S. K. Runcorn ...

Earth’s magnetism is pretty easy to forget about, being invisible to the human eye and all that. But it’s more important than you might think. The Earth acts like a giant bar magnet ...

WHEN the mean horizontal force of the earth's magnetism for each day of the year has been deduced from well-corrected observations of the bifilar magnetometer, and the results have been projected ...