indicate; but this is usually considered to belong to the Anio vetus. Those which go over the gate are the Aqua Claudia, and Anio novus. There is a series of arches of more ancient date accompanying these along the wall, but what may become of it afterwards I cannot tell. There is no range of arches near the Porta Maggiore connecting with any of the four earlier aqueducts, nor have I been able to determine them with certainty at a greater distance. We see indeed abundant remains of aqueducts, whose long branches are conspicuous objects; winding over the extensive plain, without any apparent reason for the irregularities of their course, which are the more remarkable as they sometimes cross each other; and this circumstance, added to their number, and their mutilated state, renders it difficult to trace them, or to assign to each the arches which belong to it. The elevation doubtless is a very important indication, but this requires the careful levelling and measurement of different parts. The materials are a further guide. In the three which enter the wall together near the Porta Maggiore, the two upper watercourses, supposed to be the Julia and Tepula, are formed of brick and rubble; the lower, that of the Aqua Marcia, is of square blocks of peperino, and the supporting pier is also of that construction. When the Julia was erected in 729 A.U.C., the Tepula is said to have been added to it. I do not understand what is meant by the expression, since the water is accounted for separately, and we still see their distinct channels, but it unfortunately throws a doubt on the date of the present remains; without which we might make a very near approximation to the period of the introduction of rubble-work into these buildings; between 612 A.U.C., the date of the Marcia, and 627 A.U.C., which was that of the Tepula. Of the remaining fragments, some are of stone, others of brickwork, but the former cannot be traced for any continuance; and while two or three are sometimes supported on one range of arches, in other places almost every one seems to have a range to itself. It is curious to trace these repairs executed fifteen centuries ago; the execution of the brickwork in most instances, or perhaps in all, shows them to be decidedly prior to the age of Constantine, and the principal restorations in all probability took place when the upper watercourses were added. They generally consist of brick arches, built within the ancient stone ones, sometimes resting on the old piers, but more often carried down to the ground, and in some cases the whole arch has been filled up, or only a mere doorway left at the bottom. Sometimes this internal work has been wholly or partially destroyed; sometimes the original stone-work has disappeared, as the owner of the ground happened to want bricks or squared stones. In one place the ancient piers have been entirely buried in the more recent brickwork; but the brickwork has