The massive architecture of what is left of the Theatre of Marcellus, in the same region, reminds us of Octavia’s son, to whose memory Augustus dedicated it. Twelve arches of the outer circular wall are now used as blacksmiths’ and other shops. The lower story is partly sunk in the earth. Its columns are much battered. Its arches and capitals are also badly bruised. In the eleventh century it was used as a fortress. Afterward a palace was built on the mound of rubbish within it. The historian Niebuhr, when he was the Russian ambassador, occupied it as his home. The temple of Mars Ultor (Avenger) is another of the buildings of Augustus. Before the battle of Philippi, which was such an important turning-point in his career, he made a vow that should he be victorious he would build a temple to Mars the Avenger, because the assassination of his foster-father Julius Cæsar would be avenged by such a victory over Brutus and Cassius on that occasion. With the fulfillment of this vow he combined the construction of a new Forum, or public exchange, for Rome. These noble edifices were sometimes in later centuries degraded to very commonplace uses. The Portico of Octavia, for example, was for many generations and until lately used as a fish market. The buildings mentioned were all large and costly constructions. As Augustus deposited in the Temple of Mars Ultor the rescued standards of Crassus, so for several generations victorious generals stored away their insignia in the same place. One of its features was a gallery of statues of the military heroes whose victories had enlarged the territory and glory of the empire. The costly pavement of the Forum now lies twenty feet below the present level of the ground. It requires an effort of the imagination to reconstruct the ancient scene from the old, soiled fragments. Yet it can be done by the student of all the surroundings; and future excavations will reveal much more. For a people among whom the army and war were so important, the Temple of Mars was a center of the greatest interest. Its beauty is described as of the highest sort. Augustus says in his will that the Roman citizens who fought under his orders numbered five hundred thousand. At the time of his death one hundred and sixty thousand Roman citizens were still serving under the flag. The number of men-of-war captured, burnt or sunk is stated at six hundred. [Illustration: THE CRYPTOPORTICUS]