the cathedral is 20,000 feet. Is that possible?

it is possible in the author's imagination...

You realize that much of that story is simply nonsense, don't you?

I suspect that O. Henry was making fun of the guided tours in Europe in the 19th century which were run for the English and American tourists.

That's possible. I got the sense that he was making fun of Edgar Allen Poe's detective stories, such as "The Purloined Letter," that were set in Paris and contained a fair bit of untranslated French. The French in O. Henry's story is, as you no doubt are aware, largely nonsensical.

Inspirational. I see what I should do with the translation of all the French in this story. Thank you very much!!

You know, Sam Clemens had that kind of fun with German. I don't have a link hand, but i'll bet you've read his "The Awful German Language" (or something like that). Thomas linked it for me once.

You shouldn't translate the French at all. They're words that would be vaguely familiar to many English-speakers, but strung together into meaningless phrases. For instance, the Grey Wolf says: "Que voulez vous? Avez-vous le beau cheval de mon frere, ou le joli chien de votre pere?" Literally, that means: "What do you want? Do you have my brother's good (or beautiful) horse, or your father's nice dog?" That doesn't make any sense as a question, but it's reminiscent of schoolbook exercises for students learning French, much like "où est la bibliothèque?" In the context of the story, then, the words are supposed to sound French, but they're not supposed to mean anything.

In Johann Strauss's Die Fledermaus, Eisenstein and Frank, two Austrians, are impersonating French noblemen at a ball. The two are introduced to each other as fellow countrymen, and so are expected to speak French to each other. The problem is that neither speaks French, but, to maintain their masquerade, they must make an attempt:

FRANK
J'ai l'honneur.... monsieur le Marquis!

EISENSTEIN
J'ai l'honneur....serviteur!
...

FRANK
Enchanté, mon cher.

EISENSTEIN
Pomme de terre.

FRANK
Chemin de fer

EISENSTEIN
Folies Bergère.

That was a part of A Tramp Abroad. Hilarious for anyone who has tangled with the language.

Thank you joe, I saw that, so I decided to use nonsensical Chinese to translate those French sentences and add footnotes to my translation to explain why.