"The next day the Indian told me their name for this light,--artoosoq',--and on my inquiring concerning the will-o'-the-wisp, and the like phenomena, he said that his "folks" sometimes saw fires passing along at various heights, even as high as the trees, and making a noise. I was prepared after this to hear of the most startling and unimagined phenomena, witnessed by "his folks"; they are abroad at all hours and seasons in scenes so unfrequented by white men. Nature must have made a thousand revelations to them which are still secrets to us."

Source: Henry David Thoreau (2015). “Excursions and Poems : The Writings of Henry David Thoreau, Volume V (of 20)”, p.98, HOUGHTON MIFFLIN AND COMPANY