the Burlington Arcade was built along the western part of the grounds. In 1854, Burlington House was sold to the British government for £140,000, originally with the plan of demolishing the building and using the site to build the University of London. This plan, however, was abandoned in the face of strong opposition. In 1857, Burlington House was occupied by the Royal Society, the Linnean Society and the Chemical Society (later the Royal Society of Chemistry). The Royal Academy took over the main block in 1867 on a 999-year lease, with rent of £1 per year. It was required to pay for its top-lit main galleries, designed by Sidney Smirke on a part of the gardens to the north of the main range and its art school premises; Smirke also raised the central block with a third storey. The former east and west service wings on either side of the courtyard and the wall and gate to Piccadilly were replaced by much more voluminous wings by the partnership of Robert Richardson Banks and Charles Barry Jr., in an approximation of Campbell's style. These were completed in 1873, and the three societies moved into these. In 1874, they were joined by the Geological Society of London, the Royal Astronomical Society and the Society of Antiquaries. This arrangement lasted until 1968, when the Royal Society moved to new premises in Carlton House Terrace, and its apartments were split between the Royal Society of Chemistry and the British Academy. The British Academy also moved to Carlton House Terrace in 1998, and the Royal Society of Chemistry took over the rest of the east wing. In 2004, the Courtyard Societies went to court against the Office of the Deputy Prime Minister over the terms of their tenure of the apartments in Burlington House, which they have enjoyed rent-free. The dispute was sent to mediation, after which the following statement was released: "The Office of the Deputy Prime Minister and the Learned Societies had a very constructive meeting on 16 March which envisages the continued presence of the Learned Societies at Burlington House. Discussions are continuing with a view to formalising the arrangement on a basis which is acceptable to all parties." In August 2019, the MHCLG (the successor body to the Office of the Deputy Prime Minister) gave formal notice to the Courtyard Societies that by 2022 they would have to pay commercial rents