Letters by Air: When Cities Shot Their Mail Through Pneumatic Tubes

On October 7, 1897, New York City held a small ceremony for a new kind of mail. A steel canister was loaded at the main post office, sealed and dropped into a pipe. Compressed air shoved it underground to the New York Produce Exchange and back, a round trip of 7,500 feet, in three minutes. Inside the first canister were a Bible wrapped in an American flag, a copy of the U.S. Constitution and President William McKinley’s inaugural address. Later canisters carried a full suit of clothes, a dozen eggs, two magnums of champagne, a large artificial peach for Senator Chauncey Depew, who was master of ceremonies, and, in the words of the official report, “a live cat in a cotton sack.”

Whatever the cat made of it, the idea caught on. For more than a century, from London to Paris, Berlin, Prague and New York, cities ran part of their mail and telegraph traffic through networks of buried pipes, blowing capsules of paper from office to office faster than any horse or truck could get through the streets. Paris kept its system going until 1984. A version of the same machine is now standard equipment in new hospitals.

This is the story of pneumatic tube mail: the most practical piece of Victorian science fiction ever built, and how a technology that looked like the future ended up quietly carrying blood samples.

A telegraph problem in the City of London

The tube did not begin as a postal idea. It began as a fix for the telegraph. By the early 1850s the electric telegraph could carry a price between cities in moments, but it still needed someone to carry the message from the trading floor to the telegraph office. In the City of London, those two buildings were the Stock Exchange in Threadneedle Street and the offices of the Electric Telegraph Company in Lothbury, a short walk apart.

In 1853 the engineer Josiah Latimer Clark joined them with a pipe about 220 yards long. Air pressure moved small cylinders of messages through it, and in 1854 he patented a method “for conveying letters or parcels between places by the pressure of air and vacuum.” Without it, the company would have had to employ runners or station trained telegraph operators inside the Stock Exchange itself. The pipe was cheaper and faster than either. Over the next decades the telegraph companies laid more of them, and an improved double sluice valve in 1870 sped up the work of loading and unloading. By 1880 London had more than 21 miles of telegraph tubes under its streets.

That pattern held almost everywhere the tubes appeared. The electric wire handled long distances, and the tube solved the last congested mile. It was a sort of local area network for paper, and it grew fastest wherever telegraph traffic did. The same years that produced the first transatlantic telegraph cable produced a flood of messages that someone, or something, had to carry across town.

Parcels, mailbags and a duke in a capsule

Some Victorian engineers thought small. Others wanted to send freight. In 1859 the Pneumatic Despatch Company was formed to move mailbags and parcels through tubes big enough to hold a wheeled car. Its first full-scale trial, in the summer of 1861 at Battersea, ran a cast-iron tube several hundred yards long, with a car pushed or pulled by air from a large fan.

In February 1863 the company opened a real working line in London, from Euston station to the North West District Post Office in Eversholt Street, about a third of a mile away. A single car could carry up to 35 bags of mail and made the trip in about a minute. Two years later a longer line ran from Euston to Holborn, and before it opened to traffic on 10 October 1865 the company’s chairman, the Duke of Buckingham and Chandos, demonstrated it in person by travelling through the tube from Holborn to Euston inside one of the capsules.

The ride made headlines, but the business never paid. The Post Office ran trials and found that the time savings were not substantial enough to justify the cost. It stopped using the system by 1874, and the company went into liquidation in 1875. Its tunnels were left under the streets with some of its cars still inside. Two of those original vehicles were recovered in 1930. One is now in the Museum of London and the other in the National Railway Museum in York.

The same engineer behind the Despatch line, Thomas Webster Rammell, also tried the idea on people. In 1864 he built a pneumatic passenger railway in the grounds of the Crystal Palace in south London. A carriage ran about 600 yards through a brick tunnel between the Sydenham and Penge entrances to the park, driven by a fan some 22 feet across. It lasted a little over two months as a fairground attraction. One newspaper worried that a mechanical failure might leave the passengers like “frogs under a vacuum pump.”

A secret subway under Broadway

The most famous passenger version was built in New York, by an inventor and publisher named Alfred Ely Beach, who ran the magazine Scientific American. Beach had permission to lay small postal tubes under Broadway. He used it to dig something larger. With a tunnelling shield, his crew bored a tunnel about 8 feet across and 300 feet long under Broadway, between Warren Street and Murray Street, in 58 days. It was an age when American cities were willing to rebuild themselves from below: in the years before the Civil War and during it, Chicago had jacked whole blocks of buildings up out of the mud to make room for sewers. Riders entered through Devlin’s, a well-known clothing store on the corner of Warren Street.

On February 26, 1870, Beach opened it to the public. A single car seating 22 people shuttled back and forth along the tunnel, pushed one way and pulled back the other by a huge Roots blower nicknamed “the Western Tornado.” The waiting room was lavishly decorated and even had a piano. Beach had put up $350,000 of his own company’s money. In its first two weeks the line sold more than 11,000 rides, and about 400,000 in its first year.

Beach wanted to extend the line five miles to Central Park. He never got to. The legend says that the corrupt Tammany boss William “Boss” Tweed blocked him because Beach would not pay him off. The truth is murkier. Tweed actually introduced a bill to fund the full subway, though it did not pass, and it was only after his Tammany Hall machine fell into disgrace at the end of 1871 that Beach began claiming Tweed had opposed him, partly to win support from reformers. The opposition that actually stopped the project came from powerful Broadway property owners, led by the merchant Alexander Turney Stewart and John Jacob Astor III, who feared that tunnelling would crack their buildings. Bills for the subway passed the state legislature in 1871 and 1872, and Governor John T. Hoffman vetoed both. When Governor John Adams Dix finally signed one in 1873, Beach could not raise the money in time, and the Panic of 1873 ended any hope of funding. The demonstration line closed that year.

In 1912, workers digging the BMT Broadway subway line broke into the old tunnel. Inside, they found the remains of the car, the tunnelling shield and even the piano. Beach’s subway carried no letters at all, but the postal tube permit that started it pointed the way to what came next.

Paris and its little blue letters

Continental Europe took to the tubes even more seriously, and Paris most of all. Its telegraph lines were overloaded, and the city had something London lacked: a huge network of walkable sewers. In December 1866 the first Paris line linked the central telegraph office in the Rue Feydeau to the Grand Hôtel on the Boulevard des Capucines, about a kilometre away. It did not even need an engine. The air was pressurised by water held in reservoirs 15 metres above the pipe.

The network grew quickly. A six-station loop opened in 1867, with its tubes laid in the sewers so that workmen could reach them without digging up the streets. Sewers are usually the least glamorous chapter of any Victorian city’s story (London only got its modern system after the Great Stink of 1858), but in Paris they turned out to be ideal conduits for a second, hidden network.

In 1879 the system was opened to the public. Anyone could buy a pre-paid form, write a message and drop it into a box. Officially the result was a telegram. Unlike a telegram, though, its price did not depend on the number of words. The forms were small and blue, and Parisians called them “petits bleus.” Each message was blown to the office nearest the recipient and carried the last stretch by a courier, some as young as 14, on foot or by bicycle. Messages that changed lines were stamped with the time at each transfer, so a petit bleu’s route through the city could be read off its envelope.

At its peak in 1934 the Paris pneumatic post ran through 427 kilometres of pipe and served 130 offices. Traffic peaked in 1945, when it carried 30 million messages. After that the money dried up. Maintenance was cut, the tubes wore out and blockages multiplied. In 1970 workers had to go down into the sewers 270 times to clear jammed tubes. A pneumatic message cost about three times as much as a letter in 1902 and nearly eight times as much by 1975, and telephones and telex were taking its customers anyway.

The Paris network shut down at 5 pm on 30 March 1984, replaced by a public fax service and a rapid parcel courier. A separate government line that linked the Senate, the National Assembly and the official journal of the French Republic stayed in service until 2004.

Berlin, Prague and the rest of Europe

Berlin’s network, the Rohrpost, was built by Siemens & Halske. Its first line opened on 18 November 1865, between the main telegraph office and the stock exchange. It was opened to the public on 1 December 1876, and by 1940 it had grown to almost 400 kilometres of route, linking 79 post and telegraph offices and handling about 8 million items a year.

The war and the division of the city split the network in two. West Berlin ended its public pneumatic post in 1963, as telephones and telex machines spread. East Berlin kept its side running until 1976. In between, the tubes were put to more playful uses: in 1955, guests at Berlin’s Reni Ballroom sent each other dance requests by tube, a sort of analogue text message.

Many other European cities built networks of their own. The best preserved is in Prague, often described as the last surviving municipal pneumatic post in the world. Its network, built from the late 1880s, ran through about 55 kilometres of tube under the city centre. It was still carrying documents for government offices, banks and the media into the twenty-first century, long after most of its counterparts had closed.

Then, in August 2002, the floods that swept central Europe submerged five of its eleven underground engine rooms and knocked it out of service. The telephone company that owned it later sold it to a private businessman, Zdeněk Dražil, who has announced plans to repair it and reopen it as a working tourist attraction. Its machine rooms and control panels are still there, a time capsule of nineteenth-century networking.

The New York tubes, and the trucks that won

The United States came late to postal tubes but built them on a large scale. Postmaster General John Wanamaker, better known as the founder of the Wanamaker’s department store, pushed for them in his 1890 report to Congress. In 1893 Philadelphia became the first American city to use them for mail. The engineer behind Philadelphia’s system, Birney Clark Batcheller, also designed New York’s, and his patented method became the standard American approach.

After the 1897 opening with the cat, New York’s network grew to about 27 miles of tube connecting Manhattan’s post offices and, from August 1, 1898, Brooklyn’s too, by a line across the Brooklyn Bridge. Each steel canister weighed 21 pounds empty, held around 400 letters and travelled at about 30 miles per hour. At peak times operators sent one every 6 to 15 seconds, about 360,000 letters an hour in each direction. By the mid-1920s, according to Smithsonian magazine, 55 percent of the city’s mail travelled through the tubes rather than on congested streets.

Keeping the system moving took some improvisation. When a canister jammed, a team known as the Saturday afternoon Grunters was called in. One man grunted into the tube, two colleagues listened at the other end, and a fourth timed the echo with a stopwatch to work out where the blockage was. In Philadelphia, workers fired a pistol into the tube and listened for the echo instead. Once, on an icy day, a worker had to edge along a 12-inch catwalk beside the cables of the Brooklyn Bridge to clear the line.

The tubes always had powerful enemies in Washington. They were owned by private companies, above all the American Pneumatic Service Company, and the government paid rent to use them. In 1917 Postmaster General Albert Burleson called that rent “exorbitant, unjustified and an extravagant waste of public funds.” He also called the system an “incubus,” and service was suspended on June 30, 1918. Public complaints about mail wagons clogging the streets brought it back in New York in 1922 and in Boston in 1926.

The end came in 1953. Arthur Summerfield, the new postmaster general under President Eisenhower, ran a test that December, moving New York’s mail without the tubes. He reported that “the mail can be satisfactorily handled by the addition of two trucks at a yearly cost of about $25,000,” replacing a tube service that cost the government about $1 million a year. On December 31, 1953, the contract was cancelled and the service suspended as “obsolete, unnecessary and excessively expensive.” Much of the pipe was simply left in the ground. In 2001 there was even a failed attempt to reuse it for fiber optic cables.

Where the tubes went next

Pneumatic tubes never really disappeared. They simply moved indoors. Department stores used them to carry cash and receipts; one manufacturer, Lamson, claimed over 60,000 customers around the world by 1912, in shops, banks, insurance offices, libraries and hotels. Drive-up banks used them to pass cash and documents between cars and tellers. NASA’s original Mission Control in Houston, the room that guided the Apollo landings, had tubes connecting the controllers’ consoles with the support rooms. Those tubes were later removed and sent to the Cosmosphere in Kansas for restoration. A McDonald’s in Edina, Minnesota, advertised itself as the “World’s Only Pneumatic Air Drive-Thru” until it closed in 2011.

Their real second life, though, is in hospitals. From the 1920s, hospitals began installing tubes to move records and prescriptions, and by the 1960s they were becoming standard. A 1960 hospital administrator wrote that tubes gave him eight hours of nursing from each nurse instead of six hours of nursing plus two hours of running errands. Today lab specimens make up about 60 percent of what hospital tubes carry, pharmaceuticals about 30 percent and blood products about 5 percent.

Modern hospital carriers hold up to five pounds and move through pipes six inches across at about 12 to 16 miles an hour, slower than the old postal canisters. The limit is deliberate: if blood samples travel faster, the cells can be damaged. Penn Medicine’s Pavilion in Philadelphia, opened in 2021, runs more than 12 miles of pipe and handles more than 6,000 transactions on an average day. Software tracks every carrier in real time, routing it through switches and transfer units the way a nineteenth-century clerk once routed petits bleus by hand.

The dream of riding the tube

There is one more branch of the family tree. From the Crystal Palace railway and Beach’s car onward, engineers kept coming back to the idea of putting people in the tube. The modern version, the hyperloop, was outlined in a 2013 white paper by Elon Musk: passenger pods floating on air bearings inside a low-pressure tube. Hyperloop One, one of the best-known companies in the field, raised more than $450 million and built a test track near Las Vegas, but it never won a contract to build a working line, and it shut down at the end of 2023.

The pneumatic post had a simpler answer to the question of what tubes are good for. They are very good at moving small, valuable things over short, crowded distances, where the alternative is a person walking or a vehicle stuck in traffic. That was true of a telegram crossing the City of London in 1853, a petit bleu crossing Paris in 1934 and a tube of blood crossing a hospital today. The canisters changed. The physics did not.

And somewhere in the records of the New York Post Office is the cat, who rode through the pipe in a cotton sack in 1897 and became the most reluctant passenger of a network that would carry millions of letters under Manhattan for more than half a century.

Further reading