Beside the Pillar of Phocas are two large marble screens or parapets, with magnificent bas-reliefs sculptured on both sides. They were discovered about sixteen years ago in situ, and are among the most interesting and important objects that have been brought to light by the recent excavations in the Forum. Their peculiar form has given rise to much controversy; some antiquarians regarding them as an avenue along which voters went up to the poll at the popular elections of consuls, designed either to preserve the voters from the pressure of the mob, or to prevent any but properly qualified persons from getting admission; while others believe that the passage between the double screen led to an altar. This latter opinion seems the more plausible one, for the sculptures on one side represent the suovetaurilia—a bull, a ram, and a boar, adorned with ribbons and vittae, walking in file, which were usually sacrificed for the purification of Rome at the Lustrum, as the census taken every five years was called. The other sculptures on the marble screens consist of a number of human figures in greater or less relief; one of them being supposed to commemorate the provision made by Trajan for the children of poor or deceased citizens in the orphanage which he was the first to found in Rome; and the other, the burning of the deeds which contained the evidence of the public debt of the Roman citizens, which the emperor generously cancelled. But the chief significance of the sculptures lies in their background of architectural and other objects indicating the locality of the scenes represented. They place before us a view of the Forum as it appeared in the time of Trajan, and enable us to identify the various objects which then crowded it, and to fix their relative position. The topographical importance of these reliefs has been well discussed by Signor