retaining running rights for up to three trains an hour. The Metropolitan built the railway to Uxbridge and began running services on 4 July 1904. Electrification, 1900–1906 Development At the start of the 20th century the District and Metropolitan railways faced increased competition in central London from new, electric, deep-level tube lines. The City & South London Railway had been a great success when it opened in 1890. After the opening of the Central London Railway in 1900 from Shepherd's Bush to the City with a flat rate fare of 2d, the District and Metropolitan together lost four million passengers between the second half of 1899 and the second half of 1900. The use of steam propulsion led to smoke-filled stations and carriages that were unpopular with passengers and electrification was seen as the way forward. However, electric traction was still in its infancy and agreement would be needed with the Metropolitan because of the shared ownership of the inner circle. A jointly owned train of six coaches successfully ran an experimental passenger service on the Earl's Court to High Street Kensington section for six months in 1900. Tenders were then requested and in 1901 a Metropolitan and District joint committee recommended the Ganz three-phase AC system with overhead wires. Initially this was accepted by both parties. The District found an investor to finance the upgrade in 1901, American Charles Yerkes. On 15 July 1901, Yerkes established the Metropolitan District Electric Traction Company with himself as managing director and raised £1 million to carry out the electrification, including construction of the generating station and supplying the new rolling stock. Yerkes soon had control of the District Railway and his experiences in the United States led him to favour DC with a track level conductor rail similar to that in use on the City & South London Railway and Central London Railway. After arbitration by the Board of Trade, the DC system was adopted. The District had permission for a deep-level tube beneath the sub-surface line between Earl's Court and Mansion House and in 1898 bought the Brompton and Piccadilly Circus Railway with authority for a tube from South Kensington to Piccadilly Circus. These plans were combined with those of the Great Northern and Strand Railway, a tube railway with permission to build a line from Strand to Wood Green, to create the Great Northern, Piccadilly and Brompton Railway (GNP&BR). The