Another branch went from the reservoir near the Porta Maggiore before mentioned, across the road into the bank on which the arches of Nero stand, near the Lateran, and passed under them apparently into the old _specus_ of the Appia, which runs parallel to and nearly under the arches on the other side. Two small _specus_ or stone pipes can be still seen (in 1872) passing obliquely into that bank; and, as they came from this large reservoir and _piscina_, (or from this direction,) they seem to have belonged to two aqueducts at different levels. A branch of the Marcian may have been brought to the same filtering-place for distribution, and the surplus water carried into the old _specus_ at the lowest level, which was evidently used for receiving and carrying off the surplus water of all the other aqueducts in the same line. The fifty yards outside the wall added to the three hundred yards between the Cœlian and the Aventine, make up the three-hundred-and-fifty yards above ground, mentioned by Frontinus. In this valley we found it again, in 1869, parallel to the Appia, sometimes on the _agger_ or bank of Servius Tullius, which was used as a substructure for it, in other places on an arcade built up against the tufa wall of Servius Tullius, and faced with reticulated-work. APPENDIX. ON SPĒ OR SPC̄. For the supposed Temple of Spes, the ruins of an apse in the gardens of S. Croce, of “Venus and Cupid,” (as it is marked in most maps, and as “Speranza Vecchia” in others,) was fixed upon by Piranesi, who carefully examined all that he could with a view of mapping out his aqueducts, according to the knowledge possessed in his time. This building was no doubt a hall belonging to the Sessorian Palace. Others, again, have suggested the so-called temple of Minerva Medica, but this again is a _nymphæum_, or _pantheum_, and not a temple at all. Besides, a further difficulty lies in one being too far south, while the other is too far north. Canina, in his account of the results of the excavations at the Porta Maggiore[43], and of the tomb of Eurysaces the baker there discovered, just outside of the gate, gives a plan in which he inserts a temple just inside the gate on the southern side, which he calls the Temple of Spes[44]. It is quite possible that this was a Temple of Spes. There certainly was a temple on the site indicated, where the modern guard-house stands; and during excavations carried on there, fragments of a temple of the time of the early Empire were found, consisting chiefly of a fine cornice of travertine.