In Nordic literature a remarkable discussion of the northern light appears in Kongespeilet (The King's Mirror) a thirteenth-century Norwegian chronicle. It is described in vivid detail as the following translated excerpts demonstrate: These northern lights have this peculiar nature, that the darker the night is, the brighter they seem, and they always appear at night but never by day, most frequently in the densest darkness and rarely by moonlight. In appearance they resemble a vast flame of fire viewed from a great distance. It also looks as if sharp points were shot from this flame up into...