The Emperor Alexander mosaic is not easy to find for the first-time visitor, located on the second floor in a dark corner of the ceiling. It depicts the emperor Alexander in full regalia, holding a scroll in his right hand and a globus cruciger in his left. A drawing by the Fossatis showed that the mosaic survived until 1849 and that Thomas Whittemore, founder of the Byzantine Institute of America who was granted permission to preserve the mosaics, assumed that it had been destroyed in the earthquake of 1894.