greater part of its course the conduit consists of earthen pipes, but square buildings, called Souterazi, are erected at different points upon the declivities, between the reservoirs and the city, and the level of the top of every successive pillar in the same range varies, so that their descending direction is analogous to an inclined plane commencing at the mountains. There are several ranges of these quadrangular obelisks, which present a peculiar and rather an unpleasant prospect to persons, who may not be aware of their purpose, and therefore cannot appreciate their utility.

The principal sources of the water are about fifteen miles distant from Constantinople; and in order to ascertain the proper declivity of the ground for the line of water course, an instrument is employed resembling an inverted mason's plummet, and having the name-Terazi. This contrivance being suspended from the middle of a cord, stretched between two rods, accurately divided into inches and parts, and set upright, by its successive removal from station to station, the surveyor ascertains the precise slope for the gradual flow of the water.

That the current from the various sources may be sufficiently ample, every reservoir has several circular outlets of different dimensions,-the centre of the whole being placed in the same horizontal line. As the water flows in covered tunnels, having at intervals Souterazi, these structures were probably intended to serve a similar purpose to that of the columnaria employed in the Roman aqueducts, by allowing the escape of the air from the pipes, and, likewise occasioning the deposition of any feculent matter. The obelisks are So contrived that the water ascends through a lead pipe carried up the interior of one side the building nearly to its summit, where it flows into a square basin below its orifice,

and descends by a corresponding pipe placed on the opposite side. Thus the water successively ascends and descends in its course from the reservoirs, till it arrives at its destination in the city, where it occasionally rises with great force resembling a jet d'eau.*

Contiguous to Constantinople a capacious reservoir receives the great mass of water, prior to its entering the various conduits for conveying it to that which supplies the seraglio of the Sultan, as well as the numerous fountains in different parts of the city. The latter structures are generally low quadrangular buildings, with spouts on each side, and leaden roofs curved in the Chinese manner, similar to the top of a tent, being also gaudily gilded and painted with a variety of colours, besides having upon them inscriptions in verse. These useful edifices are erected in almost every street, though, as a modern traveller remarks, "they do not indeed exhibit that splendour of architecture and ornament which Rome displays; where obedient rivers are forced into the air, or spread over artificial rocks; but they afford the pure spring and simple bowl, to invite the thirsty traveller to a delicious draught."

The aqueducts concerned in supplying Constantinople, are four in number, one of which is stated to have been constructed during the reign of Valens, and extends over the valley between the third and fourth hills. It consists of massive arches, and in a part of its length they are erected one over another, forming a double arcade. The mode of building adopted is similar to that employed for the walls of the city, which have Roman tiles and stones laid in alternate courses. It is recorded that the inhabitants of Chalcedone having opposed Valens, he resolved

• Andreossi sur Constantinople, &c.

to demolish its walls, and had the materials actually conveyed to Constantinople for the construction of this aqueduct.* Its dilapidations were repaired in 570, by Justin II.; but through neglect and the operation of time, its condition afterwards became very ruinous, when Suleyman the Magnificent not only restored it to its pristine state, but repaired all the ancient aqueducts for supplying the city. Perhaps this stupendous work may be deemed one of the most striking memorials and useful remains of the original grandeur of Constantinople. As this great structure is situate in the interior of the city, the course of some of the streets pass through the arches, and others along its sides. In many places vines, and various other creeping plants have fixed themselves in the crevices between the stones, where the water oozes out for yielding support to their roots, and the plentiful nutriment thus obtained, occasions them to grow with great luxuriance, so as to exhibit a very beautiful, diversified, and interesting spectacle.+

The other aqueducts are situate between the reservoirs and Constantinople, and have been erected to convey the water over some of the deep valleys. One of these structures is about 440 feet long, and 107 feet high; it consists of a double tier of arches ranged one over the other, and supported by strong buttresses which have also two arches at the upper tier, and one at the lower, this latter being for the purpose of rendering the edifice useful as a bridge for passengers, as is commonly the case in aqueducts composed of two tiers of arches. Another has twenty-one arches, of which ten are twice the magnitude of the others. This passes over the road leading to * Ammianus Marcellinus, lib. xxxi., cap. i. + Gyllius' Antiquities of Constantinople.

Buyukderé, and is that which was last built. There is likewise an aqueduct which conveys the water over a deep dell, and in its formation two galleries have been constructed over the arcades. The arches of the two latter have an average height and width of about sixty feet; and one of them is supported by octangular pillars, having a circumference of about 150 feet.*

The magnitude of two of the cisterns formerly employed to collect and preserve the rain-water excites astonishment; and their construction has been attributed to Constantine and Justinian. The discovery of one of these extraordinary works was made by Petrus Gyllius, an erudite and ingenious Frenchman, who resided at Constantinople for some time, during the early part of the sixteenth century. His account is not only interesting from its minuteness, but was the result of careful personal observation; and as its correctness and authenticity have been corroborated by subsequent travellers, his simple and impressive description will perhaps be deemed preferable to any other.

In describing the "seventh hill," he observes that "on the ridge there is a plain of some length and breadth. The hill itself is bounded by the land wall, and on its summit is a cistern, called Mocisia, wholly unroofed, and divested of its pillars. This cistern has a circumference of nine hundred and seventy paces; the walls still remain, and are built with square free-stone; but the ground on which it stands is now converted into a garden." Referring to a church which formerly stood on the third hill, he states, that "it is almost entirely demolished by the Mahometans, its only remains being a

• Dallaway's Constantinople.

few marble pillars, waiting the last efforts of their sacrilege. That this was a costly and magnificent building, appears from the cistern of Bonus, situate a little above it, and constructed by a nobleman of that name. Its length was three hundred paces; but its roof and columns are entirely ruined, and at present, its site is turned into a garden." In the same district, he likewise states, his having seen "three cisterns, one in the Forum of Taurus, another between the tomb of Bajazet and the Bezestan, both supported by marble pillars. The third was built on a clift of the third hill facing the north, of which there yet remain six large and lofty Corinthian pillars, made of Arabian marble and curiously wrought. Below the base of the pedestal an earthen pipe was laid for conveying water into a cistern constructed with bricks. The roof was also brick-work, and supported by twenty square brick pillars. A little above the cistern there was formerly a court belonging to a Christian church, which the Turks demolished to repair and beautify their own houses." These instances show the capaciousness of these useful receptacles for water; but those to which allusion has been made, were of a much more magnificent kind, and wholly different with regard to situation and other particulars. The relation of a few circumstances will exhibit the sagacity of Gyllius, in a very favourable light, and develope the train of reasoning by which he was led to infer the existence and site of such a stupendous excavation.

Gyllius commences his detail by observing, that "at old Rome, the Basilicae were the places in which the senates were accustomed to deliberate, lawyers to plead, and the transactions of trade and commerce carried on; but at Constantinople they were used as libraries and schools of learning, as appeared from some other facts as