Aqueduct

“ In crossing Harlem River there is a fall of 2 feet more than there would have been had the Aqueduct continued across with its regular inclination: this extra fall will afford an opportunity to adjust the number and capacity of the pipes (which descend below the level of the Aqueduct and rise again) to discharge the full quantity of water as freely as the Aqueduct, or channel-way of masonry, would have done had it continued its regular inclination across the valley. ”

“ Where streams intersect the line of Aqueduct, culverts are built to allow them to pass under it. They are simply a stone channel-way built under the Aqueduct of such form and dimensions as will allow the stream to pursue its natural direction without causing injury to the work. The foundation of these culverts is formed by laying down concrete, upon which an inverted arch of cut stone is laid forming the bottom of the water-way: side walls of stone are built and surmounted by an arch of stone. The span, or width of water way, of the culverts built, varies from 11⁄2 foot to 25 feet. ”

“ This water was very abundant, but it appeared more like the continuous stream of an aqueduct than a natural spring of water; it was at a very low level, quite 30 ft. underground. At a considerably higher level, and near the surface of the ground, was an aperture into the brick specus or conduit of an aqueduct of the third century, in which the water was flowing steadily along from west to east; this continued all the summer of 1874, and the water was always flowing. This aperture was closed in the summer of 1875, and the whole specus buried again ”

“ Aqueduct.—The total length of the aqueduct, from the intake dam to the South Reservoir, is 18,700 m., made up as shown in Table 4.
TABLE 4.—Estanzuela Aqueduct.
The gradient of the concrete pipes is 0.43% from Estanzuela to Mederos, and 0.53% from Mederos to the South Reservoir. The calculated discharging capacity of the conduit when running full is 364 497liters (13 cu. ft.) per sec. for the upper, and 465 liters (16.4 cu. ft.) per sec. ”

“ Manholes, by which the aqueduct can be entered, are usually placed in the roof at convenient intervals; thus, in the case of the Thirlmere aqueduct, they occur at every quarter of a mile.
In some parts of America aqueducts are frequently constructed of wood, being then termed flumes. These are probably more extensively used in California than in any other part of the world, for conveying large quantities of water which is required for hydraulic mining, for irrigation, Timber aqueducts.for the supply of towns and for transporting timber. ”

“ By substituting inverted syphons instead of maintaining a uniform declivity in the conduit, would not give the requisite discharge of water at the elevation of the terminus of the Aqueduct, and perhaps they preferred, rather than diminish this elevation of the supply of water, to incur the expense of high structures across valleys. ”

“ The aqueduct, forming part of the extravagant scheme of irrigation of which the Machine de Marly and the great canal of Maintenon commemorate successive disastrous phases, frames, in its useless lofty openings, such charming glimpses of the country to the southwest of Versailles, that it takes its place among those abortive architectural experiments which seem, after all, to have been completely justified by time. ”

“ The level of the pipes being thus adjusted, they will not be sprung out of place by the force generated at the descent and at the rising. For a strong current of air is generated in an aqueduct which bursts its way even through stones unless the water is let in slowly and sparingly from the source at first, and checked at the elbows or turns by bands, or by the weight of sand ballast. ”

“ This aqueduct was made in the year B.C. 145, and has its source a few miles below Subiaco; the springs are collected in a small lake called Aqua Serena (1537) , the water from which flows into the river Anio; but a portion of it was intercepted for this aqueduct, and is now again taken from the same spot and brought into Rome. It has always been celebrated for its extreme coldness and great purity. The old specus or viaduct was found in 1870 in this lake, having long been concealed by being under water ”

“ This Aqueduct is formed by two ranges of arches; those in the lower tier are seventy in number, and each 28 feet span; the piers of these arches are each 12 feet thick. The arches of the second or upper tier are much smaller, and are arranged so that three of them come within the space occupied by one of the lower arches. They are 9 feet diameter; their piers are 4 feet and a quarter thick. ”

“ The whole works on a central pier with similar arrangements to the largest swing bridges on the canal; it has two spans over the ship canal of 90 ft. each. It is somewhat singular that the first fixed canal aqueduct in England should, after the lapse of 136 years, be replaced by the first swing aqueduct ever constructed. The swing aqueduct is moved by hydraulic power, and has never given any trouble in working, even in times of severe frost. The weight of the movable portion, including the water, is 1600 tons. ”

“ In this order we proceeded, and came to a most stately Aqueduct, which runs under Ground in a direct passage five Miles, and is covered with an Arch of Bastard Marble all the Way, and a Path on both sides the Channel for two Persons to walk abreast; the Channel it self being about an English Yard in breadth, and 3⁄4 of a Yard in depth. At 20 Yards distance all the way are Ventiducts for the Air to pass, and the holes are surrounded with small Mounts of Earth to keep the Sand and Dust from falling down. ”

“ The discovery of this aqueduct has interrupted temporarily our tracing the scarp further east. It is possible that the line W—X was cut through to bring the channel within the city, and that X—Y is not the continuation of the scarp. In this case we should expect the main wall scarp to the south of the aqueduct. We have begun to open a tunnel inwards from the slope at a lower level, but have not yet reached the rock. ”

“ An aqueduct, of masonry apparently modern, leads from the level of the reservoir to the cliff at Minieh, where is a rock-cut channel three feet deep and broad, resembling more the great rock-cutting of the Roman road at Abila, than any of the rock-cut aqueducts of the country. The water was conducted through this channel to the neighbourhood of the Khân, or just to the edge of the plain of Gennesaret. ”

“ It is explained by M. Tremaux, who relates the circumstance, by the supposition—what seems indeed to have been the fact—that the tertiary fragments above alluded to had been pushed into the trench by a violent inundation, and thus filled up the aqueduct. The discovery of this aqueduct does not by any means authorise us to carry the antiquity of man as far back as the tertiary period, for, although the aqueduct lies under a stratum of tertiary formation, this stratum does not belong to the place, but was transported thither at a later period. ”

“ Between the columns the spaces are open, and from these arcades the currents of water flow with a loud noise, and in great abundance. The apertures on the sides are smaller than the others, and in each of those is placed a dragon spouting water into the spacious magnificent marble basin below. This fountain is furnished with water by the Aqueduct called Aqua Paolo; and it runs from the basin, in a very large stream into several canals, whence it is employed to work various corn, paper, and other mills, as well as to supply fountains and fish-ponds in the gardens and palaces of the opulent. ”

“ Repairs to the channel itself should not be made in the summer time, in order not to stop the flow of water at a time when the demand for it is the greatest, but should be made in the spring or autumn, and with the greatest speed possible, and of course with all preparations made in advance, in order that the conduits may be out of commission as few days as possible. As is obvious to every one, a single aqueduct must be taken at a time, for if several were cut off at once, the supply would prove inadequate for the City's needs. ”

“ Mayer tells us that the aqueduct was made of baked clay, the pipes being as perfect as when they were first laid. He also seems to imply that along the graded terraces the water was conducted in a ditch, or canal, instead of the regular pipes. But Tylor, on the other hand, says "the channel of the aqueduct was made principally of blocks of the same material [porphyry] , on which the smooth stucco that had once covered the whole, inside and out, still remained very perfect." ”

“ Whatever the reasons might have been for maintaining the elevation of their Aqueducts over valleys by such expensive structures, we have no right to charge them with the want of that knowledge which the plan of some of their Aqueducts clearly proves them to have possessed. ”

“ Aqueducts of every kind were long ago the wonders of Rome; the vast quantity of them which they had; the prodigious expense employed in conducting waters over arcades from one place to another, at the distance of thirty, forty, sixty, and even one hundred miles, which were either continued or supplied by other labours, as by cutting mountains and piercing rocks: all this may well surprise us, as nothing like it is undertaken in our times; we dare not purchase conveniency at so dear a rate. Appius Claudius, the censor, devised and constructed the first aqueduct. ”

“ Though the modern reader associates Roman318 aqueducts with the magnificent lines of arches (Fig. 12.9) stretching across a once-empty Campagna near Rome, the fact is that well under a third of a Roman aqueduct’s course was normally carried on arches: the rest was tunnel or side-hill channel. The reason for this was in part economy, in part strategic considerations: an aqueduct below ground is harder for an enemy to find and cut. ”

“ The great 186 aqueduct stretches out like a chain connecting the mountains and the plain—a chain of massive links, sadly broken and often interrupted in its long course of over sixty Roman miles. The channel is carried down the mountain-side, sometimes over and sometimes under the ground, and on the plains it is often raised on immense piers. Near Carthage it has been broken up and entirely destroyed, and the water has then to find its way through ordinary modern pipes. ”

“ These canals, reservoirs, or stagna, were brought out more clearly in 1875, and the substructures which supported them were then made visible [73] .
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In the corridors are many remains of the open channels for the water brought from the aqueducts. They are not more than a foot deep, often not so much, being frequently much worn: when perfect they are nearly of that depth, and are lined with the peculiar cement used only for the aqueducts, called Opus signinum, and in Italian, Coccio-pesto. This is an invariable mark of an aqueduct ”

“ The vast expense incurred in the construction of Aqueducts11 by the Ancient Romans, as well in Italy as in other countries of Europe, proves the value that was attached by that people to a plentiful supply of pure water, and the details of the plan of construction of the different works, evince an acquaintance with the principles of hydraulics which, at this day, is not generally accorded to them. ”

“ From the Sing-Sing Kill the Aqueduct pursues a course along the east bank of the Hudson and the first work of peculiar interest is the Aqueduct bridge over the road from Tarrytown to Sing-Sing; before it reaches this place it passes through three tunnels, over high foundation walls, and encounters deep excavations. ”

“ The aqueduct at Jouy-aux-Arches, near Metz, which originally extended across the Moselle, here very broad, conveyed to the city an abundance of excellent water from Gorze. From a large reservoir at the source of the aqueduct the water passed along subterranean channels built of hewn stone, and sufficiently spacious for a man to walk in them upright. ”

“ Extending their researches by means of the rock-cut aqueduct, they were so fortunate as to find also an old drain, through which they crawled, and examined the whole wall as far as that well-known portion of it commonly designated 'The Jews' Wailing-place.' This aqueduct was so large that a man mounted on horseback might have ridden through it, and proved of great service to the exploring party until they found it cut through by the foundations of a house. ”

“ A view is given of the Aqueduct of Spoleto, in Italy. The bridge supporting this Aqueduct is remarkable for the slender form of the piers and their great height; being only ten and a half feet thick and two hundred and fifty feet high to the base of the arches. This Aqueduct was built by the Goths, a people who gave a model for Church Architecture which is much admired at the present day. ”