The British Museum was founded in 1753, the first national public museum in the world. From the beginning it granted free admission to all 'studious and curious persons'. Visitor numbers have grown from around 5,000 a year in the eighteenth century to nearly 6 million today (referenced Mar 2010). The origins of the British Museum lie in the will of the physician, naturalist and collector, Sir Hans Sloane (1660–1753). Over his lifetime, Sloane collected more than 71,000 objects which he wanted to be preserved intact after his death. So he bequeathed the whole collection to King George II for the nation in return for a payment of £20,000 to his heirs. The gift was accepted and on 7 June 1753, an Act of Parliament established the British Museum. The founding collections largely consisted of books, manuscripts and natural specimens with some antiquities (including coins and medals, prints and drawings) and ethnographic material. In 1757 King George II donated the 'Old Royal Library' of the sovereigns of England and with it the privilege of copyright receipt. The British Museum opened to the public on 15 January 1759 . It was first housed in a seventeenth-century mansion, Montagu House, in Bloomsbury on the site of today's building. Entry was free and given to ‘all studious and curious Persons’. With the exception of two World Wars, the Museum has remained open ever since. By 1857, both the quadrangular building and the round Reading Room had been constructed. To make more room for the increasing collections held by the Museum, the natural history collections were moved to a new building in South Kensington in the 1880s. This became the Natural History Museum. The twentieth century saw a great expansion in public services. The first summary guide to the Museum was published in 1903 and the first guide lecturer was appointed in 1911. By the 1970s, there was an active programme of gallery refurbishments and an education service and publishing company had been established. Additional public facilities were provided in a series of building works. These included the Duveen Gallery, built to house the Parthenon Sculptures (1939/62). In 1973 the library became part of a new organisation, the British Library. This organisation remained at the Museum until 1997, when the books left Bloomsbury for a new building at St Pancras.