The main conduit ran, then, from the upper valley of the Ilissus to the great reservoir basin marked on the plan in [Fig. 35], but from this main conduit several branches can be traced; the most important are the branch tunnel that leads to the district of Koile and a smaller branch that goes off to water the Amyneion. Other ramifications can be traced, the object of which is not always clear; they probably occur at points where in piercing the tunnel veins of water were reached, and some served to bring to the main conduit subsidiary supplies from the Hill of the Muses and from the Acropolis.
Only those, as Professor Dörpfeld[270] himself remarks, who have taken the trouble to get right down into the tunnellings and cross tunnellings and explore them thoroughly so far as they can be explored, can form any idea of the magnitude of the work. Sometimes it is possible to stand upright in the conduit, some portions can only be reached on the hands and knees. The fact is borne in upon any one and every one who has made even a brief exploration, he feels himself unquestionably exploring what must have been the main artificial water-supply of ancient Athens, and here, if such a supply were needed, must have been the centre of the ancient city life.
The aqueduct is dated securely by comparison with the work of Eupalinos at Samos as of the time of the despots. Two striking analogies are observable between the aqueduct of Peisistratos at Athens and that of Polycrates at Samos. These are the character of the pipes, and the system of shafts. The separate pieces of the pipes at Athens are from 0·60 m. to 0·61 in length, not counting the junction points. They are made of fine yellowish clay; inside they are protected by a red glaze, outside they are left rough, except that at each end they are glazed and have a double stripe of glaze round the middle and round each end. In length and diameter they correspond with the Samos pipes, which Professor Dörpfeld carefully inspected for comparison[271]. The Samos pipes also are actually decorated with stripes, only the stripes at Samos are incised, those at Athens painted.
The same correspondence is notable in the way the pipes are joined together: both at Athens and Samos the pipes are soldered together with lead, and provision is made at both places for cleaning them. An elliptical shaped hole large enough to admit the hand is left, and is provided with a cover. A specimen of the Athenian pipes is shown in [Fig. 37], and side by side with it a section of the conduit with the pipe in position.
Fig. 37.
The pipes bear abundant traces of long use and frequent repair. In quite early days they seem to have got crusted with lime deposit from the water, and in some cases quite choked up, the water then flowed over the pipes and flooded the main channel to two-thirds of its height. In some places, where the rock was soft, it seems to have got worn away and fallen in, and portions of the tunnel became useless. New borings were made for about 30 metres and new pipes put in; these were quadrangular instead of round, but in the disused portion of the tunnel the old round pipes still lie about.
Secondly, as at Samos, at intervals of from 30 to 40 metres, both tunnels alike are provided with shafts, which served when the tunnels were first made for the clearing away of the rock fragments, and which were made use of for the like purpose when the conduit was excavated. These shafts are sunk perpendicularly; one of them reached down to a depth of 12 metres, so low does the conduit in places lie.
Of cardinal importance to us is the point at which the conduit debouches, because near to that point we may hope to find the fountain-house ‘Nine-Spouts.’ The conduit ends in an arrangement which is somewhat surprising, and which will be best understood by reference to [Fig. 38]. To the extreme left, at a point near letter B, the conduit emerges. It here consists of a massive channel built of blocks of poros stone, indicated by the thick black lines on the plan. At point a⁴ it ends in the Pnyx rock. But, and this is the odd thing, at a³, about eight metres before the channel ends, a pipe issues from the stone channel and running parallel to the Pnyx rock conducts the water to the main reservoir (Haupt-Bassin). A similar arrangement has been observed in the aqueduct at Samos. There, too, the conduit pipe leaves the rock channel before it ends. It is conjectured[272] that this was a plan intended to mislead an enemy who might desire to cut off the water-supply.
The conduit actually debouches at a⁵ into the great reservoir from which the new fountain-house Nine-Spouts must have been fed. Here, at the reservoir, we find indications of three successive structures. First a structure of very early date, possibly of the time of Solon. Second that of Peisistratos. Third a late Roman structure. Of the two earlier structures no masonry remains, but the position and dimensions can roughly be made out by markings on the Pnyx rock, out of which the West side of the basin was hewn. The exact size of the original basin, which was smaller than the later one, cannot now be determined. In the time of Peisistratos it was enlarged and deepened; the floor of the basin was sunk nearly 1·50 metres deeper. The great basin of Peisistratos was lined with masonry, the blocks of which have now disappeared. In Roman days the place of the great basin of Peisistratos was taken by a quite small structure. This change must have taken place before the building of the late Roman villa which occupied the place where once the ‘Nine-Founts’ stood. When the villa was built the great reservoir had for some time been disused, and the water from the aqueduct, not being needed on the spot in any large quantity, was carried by pipes to the lower city to the North for the supply of the new Roman market-place. These alterations as to water-supply, it should be noted, are of the first importance in questions of topography, and change in the direction or the extension of an aqueduct is naturally the index of a shifting of population.