iron and steel ribs. The width and depth are each 5 ft. 6 in., the intended depth of water being 5 ft. The staves are held by T-iron supports resting on wooden sills spaced 8 ft. apart, and are compressed together by a framework. They were caulked with oakum, on the top of which, to a third of the total depth, hot asphalt was run. The use of nails was altogether avoided except in parts of the framework, it being noticed that decay usually starts at nail-holes. It was found possible to make the flume absolutely watertight, and in case of repair being necessary at any part the framework is easily taken to pieces so that new staves can be inserted. The water in the flume has a velocity of 9.6 ft. per second. The Warm Springs, Deep, and Morton cañons on the line are crossed by wooden stave pipes 52 in. in diameter, bound with round steel rods, and laid above the surface of the ground. The work is planned for two rows of pipes, each capable of carrying 123 cub. ft. per second; of these one so far has been laid. The lengths of the pipes at each of the three cañons are 551, 964 and 756 ft. respectively, and the maximum head at any place is 160 ft. The pipes are not painted, and it has been suggested that they would suffer in their exposed position in case of a bush fire, a contingency to which, of course, flumes are also liable.
Aqueducts of New York.—There are three aqueducts in New York—the Old Croton Aqueduct (1837–1843), the Bronx River Conduit (1880–1885), and the New Croton Aqueduct (1884–1893), discharging respectively 95, 28, and 302 million U.S. New York. gallons a day; their combined delivery is therefore 425 million gallons a day. The Old Croton Aqueduct is about 41 m. in length, and was constructed as a masonry conduit, except at the Harlem and Manhattan valleys, where two lines of 36-in. pipe were used. The inclination of the former is at the rate of about 13 in. per mile. The area of the cross-section is 53.34 sq. ft., the height is 812 ft., and the greatest width 7 ft. 5 in.; the roof is semicircular, the floor segmental, and the sides have a batter on the face of 12 in. per foot. The sides and invert are of concrete, faced with 4 in. of brickwork, the roof being entirely of brickwork. There is a bridge over the Harlem river 1450 ft. in length, consisting of fifteen semicircular arches; its soffit is 100 ft. above high water, and its cost was $963,427. The construction of the New Croton Aqueduct was begun in 1885, and the works were sufficiently advanced by the 15th of July 1890 to allow the supply to be begun. The lengths of the various parts of the aqueduct are as follows:—
| Miles. | |
| Tunnel | 29.75 |
| Cut-and-cover | 1.12 |
| Cast-iron pipes, 48 in. diameter, 8 rows. | 2.38 |
| Croton Inlet to Central Park. | 33.25 |
The length of tunnel under pressure (circular form) is 7.17 m., and that not under pressure (horse-shoe form) 23.70 m. The maximum pressure in the former is 55 ℔ per sq. in. The width and height of the horse-shoe form are each 13 ft. 7 in., and the diameter of the circular form (with the exception of two short lengths) is 12 ft. 3 in. The reason for constructing the aqueduct in tunnel for so long a distance was the enhanced value of the low-lying ground near the old aqueduct. The tunnel deviates from a straight line only for the purpose of intersecting a few transverse valleys at which it could be emptied. For 25 m. the gradient is 0.7 foot per mile; the tunnel is then depressed below the hydraulic gradient, the maximum depth being at the Harlem river, where it is 300 ft. below high water. The depth of the tunnel varies from 50 to 500 ft. from the surface of the ground. Forty-two shafts were sunk to facilitate driving, and in four cases where the surface of the ground is below the hydraulic gradient these are closed by watertight covers. The whole of the tunnel is lined with brickwork from 1 to 2 ft. in thickness, the voids behind the lining being filled with rubble-in-mortar. The entry to the old and new aqueducts is controlled by a gatehouse of elaborate and massive design, and the pipes which take up the supply at the end of the tunnel are also commanded by a gate-house. The aqueduct, where it passes under the Harlem river, is worthy of special notice. As it approaches the river it has a considerable fall, and eventually ends in a vertical shaft 12 ft. 3 in. in diameter (where the water has a fall of 174 ft.), from the bottom of which, at a depth of 300 ft. below high-water level, the tunnel under the river starts. The latter is circular in form, the diameter being 10 ft. 6 in., and the length is 1300 ft.; it terminates at the bottom of another vertical shaft also 12 ft. 3 in. in diameter. The depth of this shaft, measured from the floor of the lower tunnel to that of the upper tunnel leading away from it, is 321 ft.; it is continued up to the surface of the ground, though closed by double watertight covers a little above the level of the upper tunnel. Adjoining this shaft is another shaft of equal diameter, by means of which the water can be pumped out, and there is also a communication with the river above high-water level, so that the higher parts can be emptied by gravitation. The cost of the Old Croton Aqueduct was $11,500,000; that of the new aqueduct is not far short of $20,000,000.
The Nadrai Aqueduct Bridge, in India, opened at the end of 1889, is the largest structure of its kind in existence. It was built to carry the water of the Lower Ganges canal over the Kali Naddi, in connexion with the irrigation canals of the north-west provinces. In the year 1888–1889 this canal had 564 m. of main line, with Nadrai.2050 m. of minor distributaries, and irrigated 519,022 acres of crops. The new bridge replaces one of much smaller size (five spans of 35 ft.), which was completely destroyed by a high flood in July 1885. It gives the river a waterway of 21,000 sq. ft., and the canal a waterway of 1040 sq. ft., the latter representing a discharge of 4100 cub. ft. per second. Its length is 1310 ft., and it is carried on fifteen arches having a span of 60 ft. The width between the faces of the arches is 149 ft. The foundations below the river-bed have a depth of 52 ft., and the total height of the structure is 88 ft. It cost 4412 lakhs of rupees, and occupied four years in building. The foundations consist of 268 circular brick cylinders, and the fifteen spans are arranged in three groups, divided by abutment piers; the latter are founded on a double row of 12-ft. cylinders, and the intermediate piers on a single row of 20-ft. cylinders, all the cylinders being hearted with hydraulic lime concrete filled in with skips. This aqueduct-bridge has a very fine appearance, owing to its massive proportions and design. (E. P. H.*)
Authorities.—For ancient aqueducts in general: Curt Merckel, Die Ingenieurtechnik im Alterthum (Berlin, 1899); ch. vi. contains a very full account from the earliest Assyrian aqueducts onwards, with illustrations, measurements and an excellent bibliography. For Greek aqueducts see E. Curtius, “Über städtische Wasserbauten der Hellenen,” in Archaeologische Zeitung (1847); G. Weber (as above); papers in Athen. Mittheil. (Samos), 1877, (Enneacrunus) 1892, 1893, 1894, 1905, and articles on Athens, Pergamum, &c. For Roman aqueducts: R. Lanciani, “I Commentari di Frontino intorno le acque e gli acquedotti,” in Memorie dei Lincei, serie iii. vol. iv. (Rome, 1880), 215 sqq., and separately; C. Herschel, The Two Books on the Water Supply of the City of Rome of Sextus Julius Frontinus (Boston, 1899); T. Ashby in Classical Review (1902), 336, and articles in The Builder; cf. also the maps to T. Ashby’s “Classical Topography of the Roman Campagna,” in Papers of the British School at Rome, i., iii., iv. (in progress).
For modern aqueducts, see Rickman’s Life of Telford (1838); Schramke’s New York Croton Aqueduct; Second Annual Report of the Department of Public Works of the City of New York in 1872; Report of the Aqueduct Commissioners (1887–1895), and The Water Supply of the City of New York (1896), by Wegmann; Mémoires sur les eaux de Paris, presentés par le Préfet de la Seine au Conseil Municipal (1854 and 1858); Recherches statistiques sur les sources du bassin de la Seine, par M. Belgrand, Ingénieur en chef des ponts et chaussées (1854); “Descriptions of Mechanical Arrangements of the Manchester Waterworks,” by John Frederic Bateman, F.R.S., Engineer-in-chief, from the Minutes of Proceedings of the Institution of Mechanical Engineers (1866); The Glasgow Waterworks, by James M. Gale, Member Inst. C.E. (1863 and 1864); The Report of the Royal Commission on Water Supply, and the Minutes of Evidence (1867 and 1868). For accounts of other aqueducts, see the Transactions of the Societies of Engineers in the different countries, and the Engineering Journals.
AQUILA (Ἀκύλας), (1) a Jew from Rome, who with his wife Prisca or Priscilla had settled in Corinth, where Paul stayed with them (Acts xviii. 2,3). They became Christians and fellow-workers with Paul, to whom they seem to have shown their devotion in some special way (Rom. xvi. 3, 4). (2) A native of Pontus, celebrated for a very literal and accurate translation of the Old Testament into Greek. Epiphanius (De Pond. et Mens. c. 15) preserves a tradition that he was a kinsman of the emperor Hadrian, who employed him in rebuilding Jerusalem (Aelia Capitolina, q.v.), and that he was converted to Christianity, but, on being reproved for practising pagan astrology, apostatized to Judaism. He is said also to have been a disciple of Rabbi ʽAqība (d. A.D. 132), and seems to be referred to in Jewish writings as עקילס. Aquila’s version is said to have been used in place of the Septuagint in the synagogues. The Christians generally disliked it, alleging without due grounds that it rendered the Messianic passages incorrectly, but Jerome and Origen speak in its praise. Origen incorporated it in his Hexapla.
It was thought that this was the only copy extant, but in 1897 fragments of two codices were brought to the Cambridge University Library. These have been published—the fragments containing 1 Kings xx. 7-17; 2 Kings xxiii. 12-27 by F. C. Burkitt in 1897, those containing parts of Psalms xc.-ciii. by C. Taylor in 1899. See F. C. Burkitt’s article in the Jewish Encyclopaedia.
AQUILA, CASPAR [Kaspar Adler] (1488–1560), German reformer, was born at Augsburg on the 7th of August 1488, educated there and at Ulm (1502), in Italy (he met Erasmus in Rome), at Bern (1508), Leipzig (1510) and Wittenberg (1513). According to his son, he entered the ministry in August 1514, at Bern. He was for some time a military chaplain. In 1516 he became pastor of Jenga, near Augsburg. Openly proclaiming his adhesion to Luther’s doctrine, he was imprisoned for
