Giorgio Vasari, Lives of the Most Excellent Painters… (1850)
“ On the opposite side shall be Night, and as Aurora rises, so must Night descend; as the one shows her face must the other turn her back; let the first rise from a tranquil sea, while the other must sink into a cloudy and troubled deep. The horses of Aurora must advance; those of Night must be departing. At a word, the whole presentment of the latter must differ from that of Aurora. ”
