Called St. Elmo fires by the French, Castor and Pollux by the Romans. A celestial light seen occasionally to play round mast-heads, etc. (Latin, coma, hair.) Virgil makes good use of this phenomenon while Æneas is hesitating whether to leave burning Troy or not:
Ecce levis summo de vertice visus Iuli Fundere lumen apex, tractuque innoxia mo Lambere flamma comas, et circum tempora pasci Nos, pavidi trepidare metu, crinemque flagrantem Excutere, et sanctos restinguere fontibus ignes.
When old Anchises interferes, and a falling star is interpreted to mean that Jupiter will lead them forth securely. (Æneid, ii. 682, etc.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894