North of the Piazza Capranica, in the open space called the Piazza di Monte Citorio, is a large obelisk of red syenite. This is the Gnomon Obelisk, of which Pliny gives an interesting account in his ‘Natural History.’ It was brought by Augustus from Egypt, with that which is now in the Piazza del Popolo, and was erected on the Campus Martins under the directions of the mathematician Facundus Novus to serve as a sun-dial, by which not only the hour of the day, but also the day of the month, might be shown. For this purpose the pavement of the piazza in which it stood was marked out with a complicated system of lines in bronze; and, to prevent any disturbances caused by the settlement of the foundations, they were laid as deep below the ground as the height of the obelisk itself. Pliny remarks that when he wrote, the gnomon had ceased for thirty years to mark the time rightly, and he ascribes this inaccuracy to some displacement of the obelisk due to natural causes, such as earthquakes or inundations.[96] It is more probable that the inaccuracy of the Julian calendar gradually produced the change. Ammianus Marcellinus, the Notitia, and the anonymous writer of the Einsiedlen MS., all mention this obelisk as still standing on the place where Augustus placed it. It was then—after the ninth century—lost for a time, but discovered again in 1403 with a part of the figures of the dial. Marliani, in the first half of the sixteenth century, mentions a part of the obelisk as lying neglected in a cellar near S. Lorenzo in Lucina, and it was not erected upon the present site until 1792.
To the east and north of the Monte Citorio lay the great buildings of the Antonine era, of which we still have some remains in the base of the Pillar of Antoninus Pius, now in the Giardino della Pigna of the Vatican, the magnificent Pillar of M. Aurelius in the Piazza Colonna, and the remains of the arch of the latter emperor, now in the Palace of the Conservators of the Capitol.
Pillar of Antoninus Pius.
The first of these, the Pillar of Antoninus Pius, was a monolith of red syenite, resting upon a pedestal of the same stone ornamented with reliefs. These remained upon their original site in the garden of the Casa della Missione near the Monte Citorio, until the time of Benedict XIV., when the pedestal was removed and placed in the Piazza di Monte Citorio near the Gnomon Obelisk, but the monolith was found to be so damaged, as not to be worth the expense of re-erection. Pius VI. when he placed the Gnomon Obelisk in the Piazza di Monte Citorio, removed the pedestal and took it to the Vatican Gardens, and it was finally placed in the Giardino della Pigna by Gregory XVI., who caused it to be carefully restored.
Column of M. Aurelius.
The second of the great Antonine monuments, the Column of M. Aurelius, still stands upon its original site in the Piazza Colonna. Formerly it was the centre point of a group of massive temples and colossal halls, which have entirely perished. It is now surrounded by houses of modern construction, and surmounted by a statue of S. Paul, and looks like a grey veteran clothed in the dress of a later generation, in which he feels self-conscious and ill at ease. The only remains of the colonnades, which once enclosed the court in which it stood, are to be found on the east side of the piazza in the palace of the Prince of Piombino. They consist of a triple portico of brickwork, probably faced in ancient times with marble. The Temple of M. Aurelius, which stood, like that of Trajan, in front of the column, was probably upon the western side towards the Piazza di Monte Citorio, and it is from the ruins of this temple, and not of the Amphitheatre of Statilius, as commonly supposed, that the mound of ruins called Monte Citorio may have been formed. But no traces of the substructions or of the walls or columns have been found.[97]
The column itself, which is a close imitation of that of Trajan, stands upon a pedestal which was so altered by Fontana from its original shape as to present a totally different appearance. The ancient pedestal was much less massive and better proportioned to the upper part of the monument. Its base stood at a level thirteen feet lower than the present pavement of the square, and it consisted of a basement of solid stonework about sixteen feet in height resting on three steps, nearly the whole of which is now under the level of the surrounding ground. On the east side was the door by which the spiral staircase in the interior was reached. Upon the basement stood a large square flat stone, ornamented with genii and triumphal and military ensigns, and above this the pedestal upon which, before the restorations by Fontana, only the words CONSECRATIO and D. ANTONINI. AUG. PII. were legible. The original shape and inscription of this lower part are only known to us from old prints and antiquarian notes in Gamucci, Du Perac, and Piranesi’s works. It became necessary for the safety of the pillar, in 1589 to restore the base, and the whole was cased in marble and repaired by Fontana, under the orders of Sixtus V., who at the same time placed the statue of S. Paul upon the top. From a want of accurate historical information, however, the old inscription was supposed to refer to the elder of the Antonines, Antoninus Pius, and the new inscription accordingly speaks of the monument as dedicated to him. The error was discovered by a narrower inspection of the reliefs upon the shaft, which clearly relate to the exploits of M. Aurelius.
The plinth is quite simple, and the base of the shaft is formed, like the Column of Trajan, in the shape of a laurel crown. The whole of the shaft is occupied by a spiral series of reliefs, and only a small ring of fluted mouldings separates them from the capital, which is of the Romano-Doric order. The whole pillar measures 122 feet in height, being two feet lower than that of Trajan. The shafts of the two are exactly of the same height (100 Roman feet), and are formed in the same way of solid cylinders of marble, in the centre of which the spiral staircase which leads to the top is hewn.
The great winding wreath of bas-reliefs which twines round the column contains scenes from the history of the German wars in the years from A.D. 167-179, in which a number of the tribes north of the Danube, the Marcomanni, Quadi, Suevi, Hermonduri, Jazyges, Vandali, Sarmati, Alani, and Roxolani, with many others, took part. The representations begin with an army on the march crossing a river (the Danube); then follow, as on the Pillar of Trajan, scenes in which the general harangues his troops, the enemy’s encampments are seen, and a great victory is won, accompanied with the usual thank-offerings.
But the most remarkable part of the whole relief is a scene which plainly corresponds to the account given by Dion Cassius of the sudden, and, as it seemed, supernatural relief afforded by a thunderstorm to the Roman army when hard pressed by the Quadi, who had surrounded them and succeeded in preventing all their efforts to escape. “The Roman army,” says Dion, “were in the greatest distress from fatigue, many of them were wounded, and they were hemmed in by the enemy, without water, under a burning sun. They could neither fight nor retreat, and would have been compelled to stand in their ranks and die under the scorching heat, had not some thick clouds suddenly gathered, and a heavy rain fallen, which refreshed them, and afforded them drink. This did not happen without the intervention of the gods (οὐκ ἀθεεί), for it was said that one Arnuphis, an Egyptian magician, was with Marcus Aurelius, and that he, by invoking the aid of Hermes, the god of the air, and some other deities by means of incantations, drew down the rain.” Xiphilinus, however, from whose abridgement of Dion we have the above account, declares that “Dion has purposely falsified the circumstances, for he must have known that the ‘legio fulminata’ obtained its name from this incident, the true history of which was as follows. There was a legion in the army of Marcus Aurelius, consisting entirely of Christians. The emperor being told that their prayers in such an emergency never remained unanswered, requested them to pray for help to their God. When they had prayed, God immediately smote the enemy with lightning, but refreshed the Roman army by a copious rain, upon which Marcus published a decree, in which he complimented the Christian legion and bestowed the name fulminate upon it.” History however, does not bear out this wonderful tale of Xiphilinus, for the name fulminate is known, from inscriptions, to have been given to the twelfth legion as early as the reign of Augustus.[98]