In this stage of his career Watts regularly painted images linking awe-inspiring natural events and the will of God.[20] His focus on the sun reflects his longstanding interest in it as a divine symbol; The Sacrifice of Noah, painted c. 1865, showed Noah sacrificing to the sun in thanks for his family's salvation.[17] This interest in the sun possibly came from Watts's acquaintance Max Müller, who had written extensively on solar theories of mythology (the belief that the religions of Europe, the Middle East and southern Asia were all ultimately derived from Proto-Indo-European worship of the sun).[17] Writing after Watts's death, his widow Mary Seton Watts wrote that: