You know what Gothic architecture looks like, right? Think spiral towers and scary, stony facades. Good, because that's what's going on here in the prose. The absolute epitome of this ornate, gloomy, crafted style is paragraph three (the lengthy description of Dr. Heidegger's study). If we had to sum it up in one line, we'd go with: "It was a dim, old-fashioned chamber, festooned with cobwebs, and besprinkled with antique dust" (3). The words "festooned" and "besprinkled" are so over the top we almost wonder if the narrator is mocking his own technique (see "Tone" for more). Go a little further into this linguistic treasure chest of a paragraph and you'll come out with gems like "duodecimos," "obscurest," "tarnished," "gilt," "visage," and "brocade."
The narrator's careful attention to word choice – and the resulting crafted nature of the narrative – is evident in the specific words we see used repeatedly with changing meaning. Go ahead and find the five times the word "venerable" is used in this text. At times it is ironic, at other times we can't be sure whether or not the narrator is being genuine (just like we can't be sure of the use of "festooned" and "besprinkled"). More textual uncertainty…are you seeing a theme here or what?