This essay examines how eighteenth-century naturalists selected, read, and used textual and visual sources of the past to construct chronologies of the aurora borealis from antiquity to their present. Frequent sightings of the northern lights in Europe from 1707 onward prompted investigations into not only their physical properties but also their historical patterns. These searches encountered a twofold problem. Because the term “aurora borealis” was a seventeenth-century neologism, the recovery of auroras avant la lettre required discerning them amid the various (...) aerial spectacles described in older records. Further complicating the task was the eighteenth-century authors’ suspicion of these documents as tainted by the superstitions of an “unenlightened” past. Nevertheless, these self-proclaimed “enlightened” commentators relied on the very sources they criticized in their search for lost auroras. The essay investigates how different Enlightenment auroral observers fashioned their own criteria for identifying “true” auroras through practices of extricating verbal and visual descriptions in older sources from their original contexts of portentous interpretation. (shrink)