The Valkyrior are warlike virgins, mounted upon horses and armed with helmets and spears. Odin, who is desirous to collect a great many heroes in Valhalla, to be able to meet the giants in a day when the final contest must come, sends down to every battlefield to make choice of those who shall be slain. When they ride forth on their errand, their armor sheds a strange flickering light, which flashes up over the northern skies, making what men call the "Aurora Borealis," or "Northern Lights." Even despite the very bright, nearly-full moon, the aurora was glowing intense across the Northern Hemisphere .