Final answer:
The atmosphere of Borges's poem is characterized by oppressive gloom and melancholy, with settings that emphasize sorrow, decay, and a sense of an uncanny influence on reality.
Step-by-step explanation:
The atmosphere of Borges's poem could best be described as one of oppressive gloom and melancholy. Each passage presented shows a tendency to evoke an ambiance that is heavy, laced with sadness, or conveys a peculiar sense of disquiet.
Looking at several excerpts, they consistently deliver an ambiance where the settings amplify feelings of sorrow, decay, and a sense of the uncanny or the supernatural influencing the mundane.
For example, the description of the House of Usher touches upon an intense gloom and a depressing mood brought on by the dilapidated state of the estate and the dark, heavy atmosphere surrounding it.
Different settings influence the narrative's mood; from the 'pestilent and mystic vapor' surrounding the mansion in the first excerpt to the 'dreary', and 'aweary' rhymes that paint Mariana's desolation, Borges's poetry relies heavily on setting to create a powerful emotional landscape.