 Pennethorne 's gallery was demolished for the next phase of building , a scheme by Sir John Taylor extending northwards of the main entrance . Its glass @-@ domed entrance vestibule had painted ceiling decorations by the Crace family firm , who had also worked on the Barry Rooms . A fresco intended for the south wall was never realised , and that space is now taken up by Frederic , Lord Leighton ’ s painting of Cimabue 's Celebrated Madonna carried in Procession through the Streets of Florence ( 1853 – 55 ) , lent by the Royal Collection in the 1990s . 
