piers and columns which in turn carried a large carved pediment. However, amendments to the art gallery entrance and clock tower were made. The clock and tower are known locally as "Big Brum". Construction commenced on the building in 1874 when the first stone was laid by the then mayor Joseph Chamberlain. The building was completed in 1879 and cost £163,000 (). A debate was held to decide the name of the building: the options were The Municipal Hall, Council House and Guildhall. The Council House was extended almost immediately, in 1881–85. The architect was again Yeoville Thomason. This was a combined art gallery, museum, and the home of the corporation's Gas Department, whose budget subsidised the building, as legislation limited the expenditure of ratepayers' taxes on the arts. Above the main entrance, which faces Victoria Square, the tympanum contains a mosaic by Salviati Burke and Co. of Venice. Above that, the pediment shows Britannia receiving the manufacturers of Birmingham. Victoria Square itself was once occupied by Christ Church, a building which was demolished in 1899. On 9 August 1902, The Council House, along with the Town Hall, was illuminated in celebration of the coronation of King Edward VII and Queen Alexandra. The Council House was extended a second time in 1911–19 (by architects Ashley & Newman) with a new block to the north and connected to the original building by an intricately designed archway (internally a corridor). The archway or bridge slightly resembles The Bridge of Sighs in Venice. The extension contains the Feeney Art Galleries. Architectural details Memorials Many memorials are housed within the Council House. Most are not available for viewing by the public except upon request. Memorials within the Council House are: To the citizens of Birmingham from the Belgian exiles during World War I. To the staff of the Board of Guardians who served and died in World War I. To Captain Ronald Wilkinson who died trying to defuse an IRA bomb in Edgbaston on 17 September 1973. To the staff of the City Treasurers who served in World War I and to the City Treasurers who served in World War II. To the staff of the Electric Supply Department who died during World War I. To the staff of the Public Works & Town Planning Department Memorial who died in both world wars. To the staff of the Veterinary Department who died during World