Birmingham's fine Town Hall, built to house the Triennial Music Festival, was designed by Joseph Hansom, inventor of the Hansom cab, and was completed in 1834. The inspiration for the building came from the Temple of Castor and Pollux in Rome, depicted in Palladio's treatises on architecture. The structure was brick-built and faced with Anglesey marble. Following a change of architects in 1835, a program of enlargement commenced. Further space was required to accommodate the organ, claimed to be the most powerful in Europe, funded by the musical committee of the General Hospital.