I was reading A Coffin for Dimitrios (great book), and found a character saying “send me a pneumatique when you get to Paris.” And in fact, there was a series of pneumatic tubes to speed the mail in Paris for over 100 years. Thought it was cool. Here’s the wiki as well.



New York almost had a pneumatic subway system, but the inventor tried to go around Boss Tweed. Big mistake.
https://en.wikipedia.org/wiki/Beach_Pneumatic_Transit