These two words are so interesting! The first word, “menaces,” comes from the version sent to Mabel Todd, while the second word, “obstacles,” comes from the original manuscript. They have such different tones: “obstacles” conjures something far more tangible than “menaces,” because it suggests a physical barrier, while “menaces” has greater emotional meaning because it suggests intimidation and may even personify the sunset that is the subject of the poem. Overall, the use of the word “obstacles” in the original manuscript adds to the reading of the poem as a physical description of a sunset, since adjectives are used more frequently in this version, such as “swarthy gold,” “amber,” “opal,” and “purple”. On the other hand, the use of the word “menaces” in the Mabel Todd version adds mystery to the character of the sunset, as there are less descriptive words and more shorter phrases using figurative language.