On Saturday, 18 April 2015 03:16:04 UTC+1, Nick Leverton wrote:
Opened in 1863, just a month after the Met line to Farringdon, the world's
second Underground railway was not a passenger line, but a private precursor to
the eventual Mail Rail system. And surprisingly linked to Mail Rail as well.
Worth a read on London Reconnections.

http://www.londonreconnections.com/2015/londons-lost-pneumatic-railway-the-worlds-2nd-oldest-underground/

Nick
--
"The Internet, a sort of ersatz counterfeit of real life"
-- Janet Street-Porter, BBC2, 19th March 1996

Great link - thank you.

Interesting report about Holborn ...

"Gas Buildup

"In the early twentieth century gas used for heating/lighting had a tendency to build-up in the city's sewers and underground voids, sometimes causing pavement explosions. In 1928 an explosion attributed to the ignition of a built-up mixture of coal gas and air in the old Pneumatic Despatch Railway tunnel near High Holborn and Kingsway caused one of the most serious of the era, known at the time as the "Holborn Explosion".

"It lifted the ground for hundreds of metres in each direction," said Stray, "It blew in shop fronts. There were flames that were 30 feet high in the air, that burned for hours on end. Below ground, where a lot of premises had cellar space, the walls were blown in a few inches." One man was killed, and thousands of pounds of damage was recorded. Though the cause of the explosion was never conclusively determined, the Post Office was forced to fill in or ventilate its Pneumatic Despatch Railway tunnels."

Hmm - I wonder if there's any connection between the explosion then and the recent fire?

CJB.