of the Assizes at York Castle. On 22 March 1739 the highwayman Dick Turpin was convicted at the York Grand Jury House of horse-stealing, and was hanged at the Knavesmire on 7 April 1739. Turpin is buried in the churchyard of St George's Church, where his tombstone also shows his alias, John Palmer. In 1740, the city's first hospital, York County Hospital, opened in Monkgate and it moved into larger premises in 1745. The building was funded by public subscription. The building was expanded on the same site in 1851, and finally closed in 1976 when York District Hospital was opened. Modern In 1796 Quaker William Tuke founded The Retreat, a hospital for the mentally ill, situated in the east of the city outside the city walls, which used moral treatment. The Yorkshire Museum was opened in 1830, and the British Association for the Advancement of Science held its first meeting here in 1831. Largely thanks to the efforts of "Railway King" George Hudson, York became a major centre for the railways during the 19th century, a status it maintained well into the 20th century. The Colliergate drill hall was completed in 1872 and the Tower Street drill hall was completed in 1885. On 29 April 1942, York was bombed as part of the retaliatory Baedeker Blitz by the German Luftwaffe; 92 people were killed and hundreds injured. Buildings damaged in the raid included the Railway Station, Rowntree's Factory, St Martin-le-Grand Church, the Bar Convent and the Guildhall which was completely gutted and not restored until 1960. During the Cold War the headquarters of the Number 20 Group, Royal Observer Corps was moved to the newly constructed York Cold War Bunker in the Holgate area of town. It was opened on 16 December 1961, was in operation until 1991, and was then turned into a museum owned by English Heritage. In 1971 York was made an army Saluting Station, firing gun salutes five times a year such as the Queen's Birthday. The date marked 1900 years of army in York. The University of York was launched on sites at Heslington and the King's Manor and took its first students in 1963. In 1975 the National Railway Museum was opened, near the centre of York. In October and November 2000 the River Ouse rose and York experienced very severe flooding; over 300 houses were flooded though no-one was seriously hurt. See