Editing London Underground (section)

==== Sub-surface lines ====
The idea of an underground railway linking the [[City of London]] with the urban centre was proposed in the 1830s,{{sfnp|Day|Reed|2010|p=8}} and the [[Metropolitan Railway]] was granted permission to build such a line in 1854.{{sfnp|Jackson|1986|p=19}} To prepare construction, a short test tunnel was built in 1855 in [[Kibblesworth]], a small town with geological properties similar to London. This test tunnel was used for two years in the development of the first underground train, and was later, in 1861, filled up.<ref>{{cite book |last1=Bextor |first1=Robin |title=A History of the London Underground |date=2013 |publisher=Demand Media Limited |isbn=978-1909217379 |page=34}}</ref> The world's first underground railway, it opened in January 1863 between [[Paddington]] and [[Farringdon, London|Farringdon]] using gas-lit wooden carriages hauled by steam locomotives.{{sfnp|Day|Reed|2010|pp=8, 14}} It was hailed as a success, carrying 38,000 passengers on the opening day, and borrowing trains from other railways to supplement the service.{{sfnp|Simpson|2003|p=16}} The Metropolitan District Railway (commonly known as the [[District Railway]]) opened in December 1868 from [[South Kensington]] to [[Westminster]] as part of a plan for an underground "inner circle" connecting London's main-line stations.{{sfnp|Day|Reed|2010|pp=18–24}}  The Metropolitan and District railways completed the [[Circle line (London Underground)|Circle line]] in 1884,{{sfnp|Day|Reed|2010|pp=27–28}} built using the [[cut and cover]] method.{{sfnp|Day|Reed|2010|pp=10–11}} Both railways expanded, the District building five branches to the west reaching [[Ealing]], [[Hounslow]],{{sfnp|Day|Reed|2010|p=26}} [[Uxbridge]],{{sfnp|Day|Reed|2010|p=33}} [[Richmond, London|Richmond]] and [[Wimbledon, London|Wimbledon]]{{sfnp|Day|Reed|2010|p=26}} and the Metropolitan eventually extended as far as {{rws|Verney Junction}} in [[Buckinghamshire]] – more than {{convert|50|mi}} from [[Baker Street tube station|Baker Street]] and the centre of London.{{sfnp|Day|Reed|2010|p=32}}