Monday, May 17, 2010

The Pneumatic Post of Paris

During the latter half of the 1800s, the electric telegraph revolutionized communication across Europe and the United States. The telegraph held particular importance in the financial world, where communications from the stock exchange sent across the wires could make or break an investor. However, there was still a delay for the information to get from the telegraph office to the stock exchange itself.

This potential money-losing delay prompted J. Latimer Clark's 1853 installation of a 220-yard pneumatic tube between the London Stock Exchange in Threadneedle Street and the Electric Telegraph Company's Central Station in Lothbury. By 1866, there were similar installations in Berlin and Paris. Numerous other major cities followed in their footsteps, and soon the pneumatic tubes carried individual letters and letters in bulk in addition to telegrams.

Carrying letters in bulk required larger tubes than single letters or telegrams did, and sometimes you'd see pneumatic tubes at a width of 3 inches in order to carry bulk letters. The tubes themselves worked via a pressure differential -- pressure dropped in front of the pneumatic canister, which propelled it along the tube at speeds approaching 25 miles per hour. The letters and telegrams were (and still are) always creased when they arrive, as they have to be rolled to fit in a tube.

The Parisian network, which is the subject of this post, had its first tube line put into place in 1866, between the telegraph offices at the Grand Hotel and the place de la Bourse. In 1867, this was extended into a one-way hexagon between the telegraph offices of place de la Bourse, rue Jean-Jacques Rousseau, rue de Rivoli, rue des Saints-Peres, the Central Telegraph Office (rue de Grenelle), rue Boissy d'Anglas, and back to Grand Hotel.

A map of the Parisian network of pneumatic tubes from 1971..

During the decade between 1867 and 1877, a two-day tube was laid between Central and Bourse and several additional polygonal systems were hooked into the system. The system was opened to the public in 1879, and by 1881 it was decided to connect the whole of Paris to the network. The tubes that ran through the Paris sewers mainly consisted of 65-mm diameter tubing, but from 1888 on, there were more 80-mm tubes put in. The one-way tubes within the system were also swiftly replaced with two-way tubes. As of 1974, about one-third of the pneumatic post system used the larger-diameter tubes.

Sadly, the Parisian network of pneumatic tubes -- the Poste Pneumatique -- was only in operation until 1984. At its height in 1953, the network spanned 450 kilometers underground and carried 11 million pieces of mail per year. 

Imagine seeing this system at its height. This huge system of pneumatic tubes zipping mail to and fro around a massive metropolis while the telegraph clicks away in the next office over. The frenetic activity as your Steampunk hero goes into the pneumatic post office to send a telegram zooming to the halls of power. Kind of cool isn't it? 


L. T. Host said...

That's CRAZY. Officially crazy. I always used to love pneumatic tubes at the bank, and I wondered what happened to them and where they came from... I had NO IDEA they were this widespread or massive!

Susan Kaye Quinn said...

How do you KNOW all this stuff? I'm more and more convinced you're a time traveler every day.

And I wonder ... what was the weight limit on those? Did they send stuff, not just letters? Nothing living of course (it would die of fright, if not g-forces)...but secret packages? Keys? Pocket sized valuables?

Matthew Delman said...

L.T. -- By the turn of the 20th Century, there were pneumatic tub systems set up in major cities across Europe and here in the U.S. -- New York City had one, as did Boston. In fact, the most recent closure of a pneumatic tube system (Prague in 2002) only happened because a flood damaged most of the tubing.

Susan -- Sadly, I'm not a time traveler (no matter how awesome that would be). No, my answer to how I know all this stuff is simple -- other people waste time on gossip websites or read the news of the day, but when I get bored I start researching things. My practice is to pick a period I like and start reading; sometimes that leads me to Ancient China, or Victorian England, or the American West. I do a heckuva lot more research than is probably healthy truth be told. But it's more interesting than reading about Brangelina.

Gary Corby said...

Cool about the tubes. I'd no idea they stayed in operation for so long.

How did they maintain the pressure?

Donna Hole said...

I think this was interesting; I think I was fascinated. Except, I didn't always follow.

But I like that you come up with all this interesting historical information. Some day, I'm going to be sitting in my novel, pulling my hair out because I need something and I'll be like: "oh, that thing; that thing Matt posted on. Thats exactly what I need to impose authenticity."

You're a wonder Matt, and I read your posts with enthusiasm; even when not commenting.


Matthew Delman said...

Gary -- The pressure differential was maintained first off by protecting the tubes; in Britain the pneumatic tubes were housed in lead to protect them from physical damage. Secondly, the system variously used steam-powered beam engines to suck the pneumatic capsules along the tube, or built up compressed air behind the capsule. I don't know if that answers your question or not, but that's what I know. Here's where I found that info.

Donna -- Thanks for reading even when you don't comment. I admit some of this stuff is a bit more esoteric than normal, but if it helps even one person impose authenticity then I've done my job.