Most of Seneca's Naturales Quaestiones is given over to celestial phenomena. Book 1 discusses "lights" or fires in the atmosphere; 2, lightning and thunder; 4, hail and snow; 5, winds; and 7, comets. (Book 3 concerns bodies of water; 6 is on earthquakes.) Seneca's method is to survey the theories of major authorities on the subject at hand and his work is therefore a rewarding guide to Greek and Roman thinking about the heavens.