The short story "The Thousand-and-Second Tale of Scheherazade" by Edgar Allan Poe details a great many wonders of the more modern world being described by Scheherazade to her husband, in terms familiar to them, in such a way as to sound preposterous to people of their time.
In my edition of the Collected Works of Poe, this story comes with multiple footnotes to specify the exact nature as we know it of each wonder that Scheherazade describes. Footnotes are also included in, for example, this online version.
Are the footnotes part of Poe's original text of the story, identical since its first publication? Or were they added later by an editor seeking to make the story more easily understandable?