Page:Polar Exploration - Bruce - 1911.djvu/224

220 There is no more striking or wonderful phenomenon in the Polar Regions than the aurora—Aurora Borealis in the north and Aurora Australis in the south. Any one who has wintered in the Arctic Regions has had good opportunity of witnessing the aurora in all its splendour. It is not unknown in Europe during the dark winter nights, having been recorded as far south even as Italy, Spain and Portugal. It cannot, however, be regarded as a common phenomenon in southern Europe, and indeed does not become frequent until one reaches the latitude of the north of Scotland.

"Loomis and Fritz," says the late Dr. Alexander Buchan, "have severally investigated the geographical distribution of the Aurora Borealis. The region of greatest auroral action is an oval-shaped zone surrounding the North Pole, whose central line, i.e. the more or less elliptical line halfway between the northern and southern extension of the zone, crosses the meridian of Washington in latitude 56° and the meridian of St. Petersburg in latitude 71°. It follows from this that auroræ are more frequent in North America than in the same latitudes in Europe. Loomis points out that this auroral zone bears considerable resemblance to a magnetic parallel or line everywhere perpendicular to a magnetic meridian."

"It is a fact of the greatest significance that,