Paris pneumatic postal system - how cool was that?

I love that scene too. The tubes are cool, but I think it has a deeper meaning in the context of the film. I don't think Truffaut is simply saying, "here's how we deliver mail where I live", but rather, he is showing the path of the letter and making the audience hold its breath while it goes on its way. The information in the letter is very important to Antoine. Truffaut allows the tension to build as we watch it go along, and we think about how Antoine must be in such an ambivalent state, wondering how the object of his love will feel about his letter. It made me think about all the love letters I have written and how I would always go through so many different emotions right after I dropped it in the mail, wondering if the girl is going to like it, hate it, respond to it, call me, never call me again, or just plain not get the letter at all. I think it captures everything that is the process of writing and sending a love letter, and I've never seen it done better in film. Bravo, truffaut.

I remember as a boy we had a JC Penny store in a small town. If you bought something from a salesman they sent your money and the charge slip through a pneumatic tube up to an office on a mezzenine. A few minutes later your change,receipt etc were returned to the salesman who gave it to you.

I still use one of these tubes at my local bank at the drive up windows. You put the money, deposit slip, whatever, in a tube which goes to a teller inside the bank and they return your deposit slip or money to you.

I also remember mail delivery twice a day if you can imagine that.