Show OLD o THEORIES OF THE AURORA The question whether auroras are of cosmic origin or whether they proceed horn purely terrestrial infiiii encea which still provokes discussion has from the beginning divided the learned into two parties Mairan maintained the extraterrestrial character char-acter of the meteor while the contrary con-trary opinion found a supporter in Mussohenbroek the inventor of the Leydenjar MusBOhenbroek still ev deatly under the influence of old middla age prejudices gave out the following follow-ing hypothesis Near both polls and at a little distance beneath the surface sur-face of the globe are immense reservoirs reser-voirs of phosphorescent matter Whenever a fissure is formed reaching reach-ing to them the substances readily volatile escape and illuminate tie atmosphere with their glow The frequency of auroras in particular years was explained by supposing a subterranean cavern to have been opened When the pocket was exhausted ex-hausted the phenomenon would of cause be at an end for some time So after the exhaustion of the provision of phosphorescent stuff accumulated in a particular region the meteors would necessarily cease to show themselves them-selves not to appear again till after along a-long time during which the matter would accumulate again It was thought that years of dry weather were years of maxima of auroras ana it seemed natural to suppose that moisture would hinder exhalations Extensive efforts were made without success by studying the properties of the recently discovered phosphorescent phosphores-cent substances to determine the nature na-ture of the stuff that thus shone in space Previous to this an explanation explana-tion of the phenomenon had been suggested by supposing a fermentation fermenta-tion rf f grogs expiations 1 from the earth surface which were driven I toward the pole and there took fire M Antoine Da Saporta in Popular Science Monthly |