Science: Watcher of the Pole

In Canada’s barren backlots is a small area where the compass needle, properly suspended, points directly downward. This phenomenon does not usually terrify observers: they know that they are standing on the north magnetic pole, the umbilicus of the earth’s magnetic field. When the magnetic pole changes its location, as it does, the needles of all the world’s compasses shift a little too.

Almost the only constant thing about the magnetic pole is the fact that it is forever on the move. Every day it wobbles slightly, and over the years its “mean position” drifts slowly.

The first reliable fix on the pole’s position was made in 1829-32 by Sir James

Ross, who found it on the west coast of the Boothia Peninsula (see map). Roald Amundsen, in 1903-05, found it a little northwest. Until 1933 it shifted westward; then it started east again.

Recently cheery, white-haired Russell Madill, 49, chief of the Magnetic Division of the Dominion Observatory at Ottawa, announced that the pole was some 200 miles north and 75 miles east of its previously announced location. He confirmed the observation of the navigator on the U.S. B-29 Pacusan Dreamboat, who two weeks earlier had found the pole where it was not supposed to be. The navigator’s report neither surprised nor vexed Madill, who has mothered the wandering pole for 25 years.

No one knows why the pole shifts. No one even knows why the earth is a magnet. Madill has a theory that the pole moves in an irregular orbit, completing its slow cycle in a matter of centuries. He keeps watch on its movements, working through a corps of super-tough field men. They have to be tough: observations in comfortable latitudes are helpful but not sufficient. Pole spotters have to travel into the Arctic where the pole hides out. This year three Madillmen surrounded the pole, set up delicate instruments to chart its lines of magnetic force.

Every year Arctic Canada becomes more important as a potential route for airplanes, which have to fall back on compass navigation when radio and ground contact fails them. Next season, Madill has orders to chart the position of the pole even more exactly. He may get help from the U.S. Army, which has more than a weather eye on its “Northern Frontier.”