C. Map of the corner of the Wall of Rome, shewing the great bend that it makes to the south at this point. The wall is indicated by the towers at short intervals, and the stream of water by its winding course. The roads within the walls, and the road on the outside under the wall are also indicated. The house shewn in the lower part, to the left in the plan, is believed to be on the site of that of Crassipes, the father-in-law of Cicero, near the Via Appia. The stream after passing the road turns sharply round to the north, under the cliffs of the Aventine, and runs through the Vallis Murcia, in which the Circus Maximus was made, first having passed by the Piscina Publica, under that part of the Aventine on which the Reformatory of S. Balbina now stands. PLATE XV. RIVER ALMO. MOUTH IN THE PULCHRUM LITTUS. VIEW. [Illustration: XV. RIVER ALMO, NOW THE MARRANA. MOUTH IN THE PULCHRUM LITTUS. VIEW.] This is the mouth within the Walls of Rome from the earliest period, and it was here in all probability that the priests washed the blood off their knives, and not at S. Paul’s, a mile outside the town. The remains of the early wall of tufa in this part are well shewn in the drawing, and the mouth for the stream to pass through, left when the wall was built. This was part of the second Wall of Rome, built when the peace was made between the Romans and the Sabines. The construction of that period, of the usual large blocks of tufa with very fine joints, is clearly shewn in the drawing. PLATE XVI. RIVER ALMO. MOUTH IN THE PULCHRUM LITTUS. PLAN. [Illustration: XVI. RIVER ALMO, NOW THE MARRANA. PLAN OF THE MOUTH IN THE PULCHRUM LITTUS.] In the Plan the old arrangement is clearly shewn, and the division of the stream into two branches, one of which now turns a mill-wheel, and is probably part of the alterations in the twelfth century,—this is the straight line. The other is probably the original end of the stream, or at least of this branch of it. The frequent change of the sand-banks by the great floods of the Tiber sometimes obscure this part. Advantage was taken of the water being low in the Tiber to get this plan and the view in Plate XV. THE AQUEDUCTS. PLATE XVII. SOURCES OF THE AQUA APPIA. [Illustration: XVII. SOURCES OF THE AQUA APPIA.] DESCRIPTION OF PLATE XVII. SOURCES OF THE AQUA APPIA[233]. A. Spring in a very ancient stone-quarry on the bank of the river Anio, probably one of those from which Servius Tullius had obtained the stones for his great wall, which had been floated down the river on rafts. The spring is so filled up with broken stones that it looks like merely a pond formed by drippings from the roof and the earth above, but the shepherds are certain that it is a spring, and the water never fails.