Fueling communication through pipes that ran under cities at speeds of up to 50 km per hour, the pneumatic post served as an urban subterranean communication network from the 1850s into the early 21st century, first in Europe, then the United States, and by the early 20th century, South America and Australia. Depending on the city, pneumatic tubes shuttled telegrams or letters and packages, both commercial and personal, as an antidote to increasing urban congestion and traffic on the streets above. Messages delivered by pneumatic dispatch surfaced in post offices and train stations, where messengers carried them by bicycle (or later, motorcycle or truck) from the post or telegraph branch to their final destinations. For commercial buildings, pneumatic tubes offered ready communication systems between and within any enterprises that required the movement of receipts and paper. At once buried and tangled, emerging into the interiors of buildings and offering varied interfaces for its users, the pneumatic tube presents an enigmatic image of modernity--the merger of construction and communication.Postal services and pneumatic tubes (via Beyond the Beyond)
Pneumatic networks preceded electrification, first powered by steam and only by electricity in the early 20th century. They enjoyed a long lifespan. Implemented first in London in 1853 as an information conduit between the London Stock Exchange and the Central Post Office, the technology quickly transferred to other cities. Berlin began its Rohrpost in 1865; Paris built its first pneumatic networks in 1866 and began public Poste Pneumatique in 1879; Philadelphia followed suit for first class post in 1893 and New York in 1897. Urban tube networks existed for a surprisingly long time, remaining in operation until 1953 in New York, 1984 in Paris and 2002 in Prague (where it was only taken out of service by a flood that destroyed much of the tube infrastructure).
Update: Molly adds, "the image you used is actually from the Hotel des Postes in Paris and has nothing to do with tubes. It was used for processing mail -- in order to get the mail to the basement without causing the postal sacks to explode, the architect, Julien Guadet, designed the chutes you see in that picture. The center of the chutes is an elevator, used to move the post for sorting. I'll post more about that soon."
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.