It was envisaged in 17th century by Denis Papin, French physicist and mathematician who also invented the pressure cooker. Two centuries later the idea has been materialized by the Scottish engineer William Murdoch in the 19th century and was later developed by the London Pneumatic Dispatch Company. In 1859 Thomas Webster Rammell and Latimer Clark proposed the development of an underground tube network within central London "for the more speedy and convenient circulation of despatches and parcels". It seems the engineers had aspirations for the system to eventually transport all kinds of general freight, and passengers. The company initially raised £25,000 in order to test the technology and construct a pilot route. Early experiments were conducted at the Soho works of Boulton and Watt in Birmingham.
A permanent line was constructed between the Euston station of the London and North Western Railway (beneath platform one), and the North West District Post Office in Eversholt Street (1/3 mile), using a 30 inch diameter tube and similar technology to that tested at Battersea. The line was tested from 15th January 1863, and put into operation on 20th February 1863. A single capsule, conveying up to 35 bags of mail could make the short journey between terminals in one minute, twice the speed of mailcarts. 13 journeys were operated each day, with a daily operating cost of £1 4s 5d. The Post Office were charged a nominal fee for use of the service, presumably to encourage them to accept the technology.
Construction was re-started in 1868, when additional finance was found for the route, and it was completed to Newgate Street in 1869. The Newgate Street terminus was 1,658 yards from Holborn and 4,738 yards from Euston. The journey time from the General Post Office was 17 minutes, at speeds of up to 60 mph.
If in London there was only a talk about pneumatic passenger service, in New York such service was pretty close to realization. In January 1867, the Scientific American edited by Alfred Ely Beach ran a frontpage article describing the London parcel tube system and proposing the same thing for New York. This was still for small tubes, for mail and packages. It was later that month that the Senate Select Committee reported in favor of underground passenger railways, if the problem of motive power could be solved.
In October the Scientific Americcan related that the exhibition may now be said to have reached its full glory … The most novel and attractive feature of the exhibition is by general consent conceded to be the Pneumatic Railway, erected by Mr A E Beach, of the Scientific American, and everyone visiting the Fair seems to consider himself specially called upon to visit, and, after actual experience, to pronounce his verdict upon this mode of traveling.
Beach published a promotional booklet in January 1868 called The Pneumatic Dispatch. Despite the title it covered both small dispatch tubes and larger passenger railways. The two English pneumatic railways were the models from which he was working. He credited Rammell for the concept of the entire car running in a pneumatic tube. This was what Beach wanted to do. The Rammell patents left many details of design and machinery to be developed, improved, and patented, by Beach and others.
In 1869, the Beach Pneumatic Transit Company of New York secretly constructed a 95 m long, 2.7 m diameter pneumatic subway line under Broadway, to demonstrate the possibilities of the new transport mode. The line only operated for a few months, closing after Beach was unsuccessful in getting permission to extend it - Boss Tweed, an immensely powerful local politician, did not want it to go ahead as he was intending to personally invest into competing schemes for an elevated rail line.
There were other projects, too:
But the NY elevated was built in a more conventional manner. In the meanwhile, less sensational technology conquered cities and continents: the telegraph conveyor, that became the ultimate instrument of in-city express mail service. In London, it was operated since 1853, i.e. ten years before the Pneumatic Despatch inauguration. The system conveyed messages which had been transcribed from the telegraph. Mr Josiah Latimer Clark (future companion of Rammell) installed 675ft of 1 1/2 inch diameter tube, with messages conveyed in felt bags by pressure differentials generated by a single 6 horse power (hp) engine.
Parisian Pneumatique deserves a special attention: in the 20th century it became the world's largest with 467 kilometers in total length. The network was commenced by the construction of an experimental line between the telegraph offices at Grand Hotel and place de la Bourse.
Until 1898, the use of official stationary was obligatory - blue cards with imprinted stamp and an inscription Télégramme or Carte-Télégramme (the service was operated by the State Telegraph). The customers could chose between regular and "closed" cards. The latter were double-folded with perforated and glued margins. There were also "Pneumatic envelopes", also with imprinted stamp, and reply-paid postcards (with double tariff, naturally). After the admissibility of private stationery in 1898, many Parisian printers produced light weight envelopes inscribed 'Télégramme Pneumatique' or 'Service Pneumatique'.
For generations the pneumatic letter-card was known affectionately as the petit bleu since it was on blue paper and it was under this name that a 'Télégramme' was a vital piece of evidence in the enquiries which led to the eventual acquittal of Dreyfus. At a court-martial in December 1894 he had been found guilty of passing military secrets to the Germans and was transported to Cayenne. In 1896 the contents of a waste paper basket in the office of Schwartzkoppen, the German military attache in Paris, were taken to the French Intelligence Staff and found to include a torn-up pneu which had never been sent.
Berlin tube network was the brainchild of Postmaster General Heinrich von Stephan who was also the Universal Postal Union founder. The Rohrpost was made available to the public in 1876 (before that it delivered only telegrams between the General Post Office and Stock Exchange). In 1900 it had 118 km in total length, connecting 15 post offices and delivering more than 6 million messages and small parcels annually.
Tube mail was also introduced in Munich, Hamburg, Stuttgart, Frankfurt/Main, Dusseldorf and Chemnitz.
In Vienna, the pneumatic mail was opened to the public in 1875, beginning with modest 14 km line and expanding to 82,5 km in 1913. At its peak it connected 53 post offices, delivering 20,000 capsules per day.
Here's a letter from Serbia that made its final "leg" (between the main and the local post offices) by tube:
At the beginning of the 1890s Charles Emory Smith, a former newspaper editor and ambassador to Russia, was appointed Postmaster General. An $8 million pneumatic system was developed in major Eastern US cities. A 6 inch diameter, 3,000 foot long system was constructed in Philadelphia between 1892 and 1893, for the transport of mail between two post offices.
An 8 inch diameter line was added by Congress between 1897 and 1898, along with three new lines in New York and one in Boston. The lines allowed the movement of mail between post offices and neighbourhood post offices, and to railway terminals. In 1902 additional lines were added in New York and Chicago, with an additional lines in St Louis in 1906 taking the entire network to 63 miles of 'double tube'.
Canisters (capsules) containing up to 500 letters travelled at 30mph under the streets of a number of cities. By 1916 systems were in place in Boston (14 miles of tube), Chicago (20 miles), New York (55 miles), St Louis (4 miles) and Philadelphia (20 miles). Extensive use was made of some of the larger systems - typically a third of all first class letters passing through the New York mail system were distributed in part via pneumatic tubes.
In 1918 debate about the relative costs of different systems for moving mail came to the fore. A Congress committee found that use of the pneumatic tubes cost $17,000 per mile per annum, with rental charges for the tubes an 'exorbitant, unjustified and an extravagant waste of public funds'. This combined with the growth of the automobile and traffic control systems in major cities, marked the end of further development for the pneumatic mail networks. However, all but the Philadelphia system operated until the 1950s. In 1900 Charles Emory Smith had predicted that pneumatic tube systems would eventually link every household to the rest of the network. This dream was never to be realised; at least not yet...