Pneumatic trains were to the Victorians something like maglev trains are to us: a transport technology of the future that seemed destined to remain there. They even merited some light sarcasm from George Eliot, in the introduction to Felix Holt: The Radical:
"Posterity may be shot, like a bullet through a tube, by atmospheric pressure from Winchester to Newcastle: that is a fine result to have among our hopes; but the slow old-fashioned way of getting from one end of our country to the other is the better thing to have in the memory."
What I hadn't realised until the other day was that there was an actual pneumatic railway in London in the 1840s - and that I used to live on the route of it. According to The Phoenix Suburb: A South London Social History, by Alan R. Warwick, the London and Croydon Railway ran air-powered trains between West Croydon and Forest Hill from October 1845.
The service was smooth, and silent, and apparently capable of exceeding 60mph. It had three ornate architect-designed pumping stations: "the most beautiful things of their kind that have ever been erected in this country". It was also ahead of its time in the literal sense that, when it was built, the materials did not exist to make it work properly.
The trains drew their air power from a pipe between the tracks, connecting to it through a "longitudinal valve", which a few decades later would have been made from toughened rubber. In 1845, it was a leather flap lubricated and sealed with a mixture of wax and tallow.
This was all right except in summer, when the tallow melted and the leather became too floppy; in winter, when the tallow froze and the leather became too stiff; and in spring and autumn, when rain washed the tallow off altogether. Oh, and the tallow mixture was also delicious to rats, which would "invade the track nightly":
"When the pumps started up in the morning, rats would be sucked through the pipe into the pumping station. To combat this, the engine room men placed open sacks over the inlet, to catch the rats as they poured in."
Less than a year after the experiment began, the London and Croydon merged into another railway, and the new company turned off the pumps for good.
[The Phoenix Suburb: A South London Social History, by Alan R. Warwick, Blue Boar Press, 1976. Haven't finished it yet, but so far it is proper old-school local history, full of street names and semi-disclaimed sensational anecdotes. It's also magnificently provincial. "Whether a suburb is S.E. or S.W., or N. or E., or whatever," says the preface, "it represents a way of life." In this sentence, as best I can tell, "whatever" covers the entire world beyond the inner London postcode system.]