installed along the Victoria Embankment as an experiment to gauge the respective brightness of gas vs. electricity, and the latter was judged superior by the Board of Works. The same year, Siemens installed electric light in the Royal Albert Hall and along Waterloo Bridge, while the first large power station in the metropolis opened at Deptford. Another major advancement was the construction of the Edison Electric Light Station at Holborn Viaduct in 1882, the world's first coal-fueled power station for public use. The station, opened by Thomas Edison's Edison Electric Light Company, powered 968 lamps (later expanded to 3,000) stretching from Holborn Viaduct to St. Martin's Le Grand, using Edison carbon-filament incandescent light bulbs. Culture Museums Several of modern London's major museums were founded or constructed during the 19th century, including the British Museum (built 1823–1852), The National Gallery (built 1832–8), the National Portrait Gallery (founded 1856), and the Tate Britain, which opened in 1897 as the National Gallery of British Art. The British Museum had been established by Act of Parliament in 1753, and housed since that time in the 17th century Montagu House in Bloomsbury. With the donation of the King's Library in 1822, which comprised some 120,000 manuscripts, pamphlets, and drawings assembled by the late George III, a major extension of the museum was needed. Montagu House was demolished and the quadrangular current building, with its imposing Greek Revival façade designed by Sir Robert Smirke, rose gradually through 1857, with the East Wing the first to be completed in 1828. The Round Reading Room, which was built to occupy the vacant courtyard behind the main building, featured the second largest dome in the world when it was finished (140 feet in diameter). By 1878 the Reading Room contained 1.5 million printed volumes across some 25 miles of shelves. The great complex of museums at South Kensington began with the purchase of a vast tract of land (known as Albertopolis) at the instigation of the Prince Consort and the Royal Commission for the Exhibition of 1851. The profits from the Exhibition were put toward the purchase of the land, which was intended to host a complex of cultural, scientific and educational institutions. The first of these was the South Kensington Museum (now known as the Victoria & Albert Museum), which opened to the public in 1856. The South Kensington Museum at that time inhabited the 'Brompton Boilers' building