Budapest Régiségei 24/1. (1976)

ÓBUDA, RÓMAI KORI TÁBOROK, CANABAE ÉS KÖZÉPKORI VÁROS = ÓBUDA, ROMAN CAMPS, CANABAE AND THE MEDIEVAL TOWN = OBUDA, LAGERÂ I KANABE RIMSKOJ EPOHI I SREDNEVEKOVYJ GOROD - Kaba Melinda: Az aquincumi aquaeductus pilléreinek 1975. évi kutatása : előzetes jelentés 225-232

MELINDA KÁBA THE 1975 EXCAVATIONS OF THE PIERS OF THE AQUEDUCT AT AQUINCUM (PRELIMINARY REPORT) y Previous to the construction of route M-ll, excavations were conducted at the supposed track of the piers of the aqueduct,to the north and south of the Aquincum stop of the suburban railways. By means of this work 93 piers were determined, and Ernő Foerk* s site plan, as well as the so-called "Mary'

s Stone": a pier transposed in the axis of Benedek Elek Street Budapest, 3rd district, were authenticated. The uncovered monumental remains of piers were preserved in an unexpectedly good condition, overground traces. At several points connecting archings were found in situ also, which permit the conservation of two piers each in then original condition. The height of the floor level of the construction of the original Roman piers is 104. 5 m. The floor was made with terrazzo. The measurements of the piers agree with Foerk's data: the footing is 60 cm., the shoulder ridge of the arching starts from a 15 cm. long pier shaft. On top of several of the pier stumps the traces of the one-time horizontal trough and also the leaden fillers of the perpendicular piping have been preserved. The conduits of the piers show branchings towards the eastern and western parts of the town. Unfortunately, however on account of the narrow space at disposal the position of neither of these, nor the brick-covered outlets could be cleared up. Namely, in the west the line of the suburban railways and in the last the power transmission line (10.000 V) were in the way of the excavation. The works of opening up were accompanied by rich ceramic finds. The Aquincum aqueduct has been repeatedly mentioned from as far back as the Middle Ages. In technological respect it was Ernő Foerk who examined it first: on the occasion of the works of railing in 1911. The conduit gained the water from the springs called Rómaifürdő (Roman Bath) at present, by means of an engine raising it into the trough or pipes placed upon the piers, as this is known with aqueducts uncovered in other areas of the Empire. On top of the piers there are amorphous spongy formations which enclose the shoulders of the arches and the crowns in several places. The blocks stood for a long time on the ground. When examining them, on the surfaces the author could observe dropstone- and bulging spherical deposits well-known from caves. She invited associate professor Pál Kertész to give an expert opinion, and the latter found that the water system of the Roman Bath was characteristically of cavern-water origin, and that at relative saturation calcium carbonate might be precipitated from it. The phenomenon is a result of lasting, long- continued dripping of water. The lenght of time needed for the formation cannot be exactly given. Sedimentation is a function of a great number of factors. Even in case of identical water levels it depends on the temperature of the place of dripping and on its intensity, as well as on the flow velocity and quantity of the water carried in the conduit. Visible to the naked eye the porous and vesicular formation of part of the uncovered aqueduct elements is dissimilar to the character of the other unearthed rocks. The considerable differences of the surface have been caused by the circumstance that the parts showing interstices underwent a double geological process on one hand calcium carbonate could be precipitated from the water seeping from the acueduct in these places, on theother hand the rock surfaces, having been on the surface for a long time began to decay. To sum it up, it can be stated that the mentioned phenomena are results of well definable mineralogic-geological processes also otherwise characteristic of Óbuda and its environs. 229