The Aqua Julia at this point, which is about four miles from Rome, is just underground, and this loch and branch to supply the Villa was discovered about 1850 by Signor Moraldi, when he was making a map of the Aqua Marcia, with a view to having it brought again into use; which has since been done, but by a different line.—To save carrying it so far round as the old aqueduct was carried (in order to avoid the mouths of the many streams that run into the river Anio), the modern engineers used metal pipes in this part. Above Tivoli they built a stone _specus_ after the old fashion, as in that stone country they found it the cheapest and the best plan. They now say they regret that they did not continue the stone _specus_ over the level Campagna also, as the metal pipes are continually bursting from the force of the water. Previous to this discovery of Signor Moraldi, it was not known that there were lochs in the aqueducts, though it is obvious that when branches had to be taken from them, such an arrangement would be required. The Tepula and the Marcia are underground in this part. The Julia, being the uppermost of the three, was close to the surface. This was also the case on the side of the great _agger_ of Servius Tullius near the railway station, where the Julia only was excavated, with two cippi, on which were inscriptions stating that _the three_ aqueducts passed there. PLATE VIII. AQUEDUCTS AND RIVER ALMO, NEAR THE PORTA FURBA. [Illustration: VIII. THE AQUEDUCTS AND RIVER ALMO, NEAR THE PORTA FURBA. A. PLAN AT A CROSSING. B. PLAN AND SECTION AT ANOTHER POINT. C. PLAN AND SECTION IN THE QUARRY AT THE ALBERGO DE’ SPIRITI. D. PLAN AND SECTION OF RESERVOIR NEAR THE SAME.] A. Arcades of the Marcia, Tepula, and Julia; the Claudia and Anio Novus at one of the angles and crossings; and the Aqua Felice, which is carried first on one and then on the other of the old arcades. Also, there is an indication of the situation of the great tumulus and tomb called “Monte del Grano,” in which the fine sarcophagus was found which is now in the Capitoline Museum, and was long supposed to be that of the Emperor Alexander Severus and his wife Mammea. This is given to indicate the situation. The river Almo is seen crossing the two arcades near the gate or arch over the road. B. The same two arcades, at about a quarter of a mile nearer to Rome, or just two miles, with the river Almo winding between them; and a Section to shew the elevations. C. Plan of the junction of the old Via Latina, with the modern road to Albano, at two miles from Rome, shewing the situation of the aqueduct in a stone-quarry at the back of the “Albergo dei Spiriti,” near C. D. Plan and Section of the reservoir, at two miles from Rome, near the Porta Furba. PLATE IX. THE SEVEN AQUEDUCTS AT THE TOR FISCALE. [Illustration: IX. THE AQUEDUCTS AT THE TOR FISCALE. A. SECTION. B. PLAN, SHEWING THE CROSSING OF FIVE AQUEDUCTS IN THE TOWER, AND TWO UNDER IT.]