THE AQUEDUCTS OF ANCIENT ROME

DR. THOMAS ASHBY

T is a curious fact that the monuments of the power of

a that borders of her empire are, in re

ality, better known than those that lie at her very gates. One need not perhaps be surprised if minute details of the topography of the Roman Campagna are left to investigators of the present day, so much more fortunate than their predecessors in the all important matter of maps—so much so, indeed, that the discoveries of some of the earlier explorers have been forgotten, partly because their descriptions were of necessity vague and not easy to understand, and partly also owing to a failure on the part of the Nineteenth Century topography to recognize the value of the work done by such scholars as Holste and Fabretti in the Seventeenth Century and Capmatin de Chaupy in the Eighteenth.

But that the aqueducts should have shared in the general oblivion is somewhat remarkable. Considering the fame which the arrangements for the water supply of Ancient Rome justly enjoyed-a Greek writer of the Augustan epoch speaks of the aqueducts, the roads, and the drainage system as the most striking of the public works of the city -it is noticeable that they have not formed a subject of study for more recent investigators. Here even the dili

gence of the Seventeenth and Eighteenth Century scholars fails us. Canina, in the fifth and sixth volumes of his Edifizi di Rome Antica, gives descriptions and drawings of some of the most prominent remains in the Anio valley and in the neighbourhood of Tivoli and Gallicano, and in the third and fourth volumes of the well-known line of arches in the immediate neighbourhood of Rome; but the only comprehensive work on the subject is Lanciani's Comentarii di Frontino intorno le acque e gli aquedotti. This monograph is based upon the treatise on the aqueducts written by Sextus Julius Frontinus, who was curator of the whole system under Trajan, and upon much original research, and is by far the best treatise on the subject available; but many problems are still left unsolved. Since this work was written, the construction of railways has rendered further study far easier than it previously was, the remoter parts of the Campagna, hitherto with difficulty accessible, having been brought within easy reach of Rome. But no one seems to have felt the desire of filling up the gaps in our knowledge which still remain, nor of superseding, or even adding to, the available illustrations of the portions of the aqueducts which are already known.

Of the eleven aqueducts of Ancient Rome the four most important are those which come from the valley of the Anio above Tivoli-two of them, the Anio Vetus and Anio Novus, taking the water from the river Anio itself, and the other two, the Marcia and Claudia, from springs which rise in the river valley. The rest divide themselves topograph

126 THE AQUEDUCTS OF ANCIENT ROME ically into four more groups-the Appia and Virgo, which rise from the low ground between the Via Collatina and the Anio, the Alexandrina, which comes from springs to the southeast of Gabii, the Tepula and Iulia, which are taken from the lower northern slopes of the Alban hills and the Alsietina and Traiana, which drew their supplies from the district near the lake of Bracciano, on the right bank of the Tiber.

The first group is by far the most interesting, as well as the most important. The distance traversed by the shortest of the aqueducts from the Upper Anio valley is three or four times as great as the length of any of the others on the left bank, and the country through which they pass presented far greater obstacles to their engineers. There has been, indeed, a considerable gap in our knowledge of them, their course having been hitherto unknown from Ponte Lupo, near Gallicano, to Le Capanelle, where the long line of arches, so well known to all visitors to Rome, begins. A suggestion was made by Professor Lanciani that the calcareous deposit which is so abundant in the water, and which was thrown out at the shafts, by means of which the aqueducts were ventilated and could also be entered for cleaning, ought to betray their presence in the volcanic district through which this portion of their course lies. Investigations on the spot were amply rewarded, and I have been able to ascertain the course of each of the four from point to point. It would be well worth while, though it would require a considerable expenditure of time,