Pneumatic post or pneumatic mail is a system to deliver letters through pressurized air tubes. It was invented by the Scottish engineer William Murdoch in the 1800s and was later developed by the London Pneumatic Dispatch Company. Pneumatic post systems were used in several large cities starting in the second half of the 19th century (including an 1866 London system powerful enough to transport humans), but were largely abandoned during the 20th century.   It was also speculated that a system of tubes might deliver mail to every home in the US. A major network of tubes in Paris was in use until 1984, when it was finally abandoned in favor of computers and fax machines. In Prague, in the Czech Republic, a network of tubes extending approximately 60 kilometers in length still exists for delivering mail and parcels. Following the 2002 European floods, the Prague system sustained damage, an operation was mothballed indefinitely. Pneumatic post stations usually connected post offices, stock exchanges, banks and ministries. Italy was the only country to issue postage stamps (between 1913 and 1966) specifically for pneumatic post. Austria, France, and Germany issued postal stationery for pneumatic use.   Typical current applications are in banks and hospitals. Many large retailers use pneumatic tubes to transport checks or other documents from cashiers to the accounting office. One system lists a speed of 10 meters per second.  

Historical use

1853: linking the London Stock Exchange to the city's main telegraph station (a distance of 220 yards).

1865: in Berlin (until 1976), the Rohrpost, a system 400 kilometers in total length at its peak in 1940.

1866: in Paris (until 1984, 467 kilometers in total length from 1934).

1875: in Vienna (until 1956).

1887: in Prague (until 2002 due to flooding), the Prague pneumatic post.

1897: in New York City (until 1953).

Other cities: Munich, Rio de Janeiro, Buenos Aires, Hamburg, Rome, Naples, Milan, Marseilles, Melbourne, Boston, Philadelphia, Chicago, St. Louis.