What is the meter in Poe's "The Black Cat"?

"The Black Cat" is a short story by Edgar Allan Poe. "Meter" is a term used to describe the pattern of stressed and unstressed syllables in verse. Since "The Black Cat" isn't poetry, it has no meter.
We use designations of meter to discuss rhythm in poetry. Although "The Black Cat" doesn't have meter, Poe's sentences in the story definitely have a notable rhythm or cadence to them. This is evident in the first paragraph of the story. The prose flows so elegantly that one might believe it could be verse if it were broken into lines like poetry. But there is no consistent meter as in traditional verse forms.
Poe achieves the flowing rhythm of his prose by several techniques that good writers use, among them sentence variety, parallelism, and tricolons. Taking just the first paragraph, we can see how Poe uses these strategies to lend a lovely cadence to his writing. Most of the sentences in this paragraph are long, with many phrases and clauses that must be separated by commas or dashes. In the middle of the paragraph, Poe breaks up that long, winding cadence with a short, simple sentence: "Yet I will not attempt to expound them." The way each sentence begins varies: sometimes with a transition word such as "but" or "yet," sometimes with the subject, and sometimes with a prepositional phrase. One sentence reverses the normal word order for emphasis: "Mad indeed would I be..." This variety of sentence structures aids the paragraph's rhythm.
Parallelism is the positioning of words, phrases, or clauses of the same grammatical structure in proximity to each other. Examples are as follows: "I neither expect nor solicit belief," "tomorrow I die, and today I would unburden my soul," "to me ... to many." Parallelism creates an easy flow that carries the reader through the prose.
Finally, tricolons are lists of three words, phrases, or clauses. Three is a powerful number, and tricolons are a strong rhetorical device that adds a definite rhythm to one's writing. Examples of tricolon are as follows: "plainly, succinctly, and without comment," "have terrified—have tortured—have destroyed," and "more calm, more logical, and far less excitable." As the three elements build, a mini-crescendo is achieved each time.
An analysis of Poe's use of words and phrasing to produce a flowing rhythm—even in just the first paragraph of the story—reveals how skillful a writer he was. His story does not have meter, but it has a beautiful, haunting cadence.
https://literarydevices.net/meter/

https://mannerofspeaking.org/2015/03/16/rhetorical-devices-tricolon/