From oobject.com, 15 pneumatic message networks:
Ted Stevens was right, the Victorian Internet consisted, quite literally, of a ‘Network of Tubes’. Paris, London, Prague and Vienna had extensive networks of pneumatic tubes which delivered messages in capsules. In New York 5 million mail messages passed every day through an underground pneumatic system, and a network in Berlin delivered hot meals directly to people’s homes suggesting that kitchens would no longer be needed in the future. Today these systems can still be purchased where they are used in places like hospitals where samples are passed between departments.
If you have ever used one of these, as I have at an educational institution many years ago, you’ll never forget the immensely satisfying pneumatic plump sound when your payload is sucked up the tubes.