In postal service
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 19th century 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 and large enough to transport humans during trial runs - though not intended for the purpose), but were largely abandoned during the 20th century.
|Pneumatic tubes in use at a drive-through bank.|
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.
|Spirit of Saint Louis US airmail stamp of 1927.|
In the American animated science fiction sitcom Futurama this system is usually used to deliver letters: