These tubes were large, 24"L x 8" diameter. You could fit all sorts of stuff in there. It's so interesting to think that food, mail, and small package delivery in NYC could have peaked way back when pneumatic tubes were used (of course only in the optimal case with start/end near one of the 23 tube stations). Also really cool that there was a tube that ran over the Brooklyn bridge for sending mail or burritos between boroughs.
For further reading on unique NYC infrastructure, the New York City steam system is also very interesting and still in operation.
https://untappedcities.com/2023/10/17/pneumatic-tube-mail-ne...
A lot of the material was also incorporated in their podcast about the same subject:
https://podcasts.apple.com/us/podcast/pneumatic-tube-mail-in...