been broken, and the original stone-work taken away, presenting a very singular, and at first sight, wholly unaccountable appearance; in other parts the whole has fallen, apparently without having had these brick additions, for a range of parallel mounds marks the situation of the prostrate piers. Continuing along the road to Præneste, the ancient Via Labicana, for some distance, with these aqueducts and fragments of aqueducts on the right, and observing another, crossing a valley on a much lower level, perhaps connected with the lowest watercourse (that of the Anio vetus) at the Porta Maggiore, we arrive at the Torre Pignattara, said to be the tomb of Helena, the mother of Constantine. Here was found the other great porphyry sarcophagus now in the Vatican, the position of the first I have already mentioned in the church of Santa Constanza. The sculpture is far from good, but it is better than the former. It is said to have been repaired in modern times at the expense of 20,000 crowns, otherwise it might be deemed too good for the age of Constantine. The tower itself is a circular brick building of considerable size, with two stories externally, each of eight arches. There has been a large external niche in the part opposite to the present entrance, and some projecting stones announce a cornice, or perhaps a peristyle, above the lower range of arches. There probably was never much to be admired in it either for design or execution. The dome which covers it is constructed with earthen pots, and the building has thence obtained its name, Pignattara, signifying a pipkin.