Res Gestae
Ammianus Marcellinus
Ammianus Marcellinus. Ammianus Marcellinus, with an English translation, Vols. I-III. Rolfe, John C., translator. Cambridge, MA; London: Harvard University Press; W. Heinemann, 1935-1940 (printing).
If, on the other hand, they stand in the nodes themselves which closely unite the ascent and the descent, the heaven will be overcast with thicker darkness, so that because of the density of the air we cannot see even objects which are near and close at hand.
Now it is thought that two suns are seen, if a cloud, raised higher than common and shining brightly from its nearness to the eternal fires,[*](I.e. the sun.) reflects a second brilliant orb, as if from a very clear mirror.