Exhibitions such as that of Glasgow in 1901, of Saint Louis in 1904 and that of San Diego in 1915. It was thus seen appropriate to continue this tradition and so install an organ for the new Exhibition in Barcelona. The organ was built in 1929 by E.F. Walcker & Cie. from Ludwigsburg (Germany). The mechanisms entirely electric and consisted of 154 music registers divided into five keyboards and a pedal keyboard of thirty-two notes, with more than two thousand organ pipes. It was inaugurated by Professor Alfred Sittard on the 6th of July 1929. The organ was restored and enlarged in 1955, wherein two thousand five hundred new pipes were added to the previous amount. With the expansion of the organ it now contains six keyboards and measures a total of eleven meters in height and 34 meters in width. Throne Room The Throne Room (), also known as the Conference or Proceedings Room (), is that decorated with the most noble of materials. Each wall surface is treated with different coloured marbles, realized in the formation of geometric designs. Above the throne hangs a portrait of King Alfonso XIII. It is an oil painting which was commissioned for the occasion of the 1929 Exhibition and was realized by the Barcelona painter Richard Canals. The lateral walls of the room are decorated with allegorical paintings referencing the Exhibition of 1888 and realized by Francesc Labarta; others relate to the Exhibition of 1929 and were painted by Xavier Nogués. The painter Josep Obiols i Palau also contributed with a series of four frescos depicting the cardinal virtues: Fortitude, Temperance, Justice and Prudence, located in the four tympana of the arches in the Throne Room. Principal dome For the decoration of the dome, Lluís Plandiura suggested that is should be entrusted to one of the best Catalan artists of the time. For this reason the central part of the dome (a surface area of about 300 m2) was realized by Francesc d'Assís Galí, who was contracted to represent ‘in a tremendous way, the grandeur of Spain, justified in a symbolic composition defined by four fields: Religion, Science, Fine Arts and Land’. Religion: The scene of Christ crucified, at his sides are the figures of a martyr and an angel, at his feet, an infidel. Another scene depicts a Saracen leader handing over the keys of a city to the Christian army.