See also:

• CAISSON (from the Fr. caisse, the variant form " cassoon " being adapted from the Ital. casone)

CAISSON (from the Fr. caisse, the variant See also:

• FORM (Lat. forma)

form " cassoon " being adapted from the Ital. casone)  , a See also:

• CHEST (Gr. Kiarl, Lat. cista, O. Eng. cist, test, &c.)

chest or See also:

• CASE
• CASE, JOHN (d. 1600)

case . When employed as a military See also:

• TERM

term, it denotes an See also:

• AMMUNITION

ammunition See also:

• WAGON, or WAGGON

wagon or chest; in See also:

• ARCHITECTURE (Lat. architectura, from the Gr. ap)(LTEKrwv, a master-builder)

architecture it is the term used for a sunk See also:

• PANEL (O. Fr. panel, mod. panneau, piece of cloth, from Med. Lat. pannellus, diminutive of pannus, cloth)

panel or See also:

• COFFER (Fr. coffee, O. Fr. cofre or cofne, Lat. cophinus, cf. " coffin ")

coffer in a See also:

• CEILING (from a verb " to ceil," i.e. to line or cover; of disputed etymology, but apparently connected with Fr. ciel, Lat. caelum, sky)

ceiling, or in the See also:

• SOFFIT (from Fr. soffite, Ital. soffitta, a ceiling, formed as if from su. fjictus for suff xus, Lat. suffigere, to fix underneath)

soffit of an See also:

• ARCH
• ARCH, JOSEPH (1826– )

arch or a vault . In See also:

• CIVIL

civil See also:

• ENGINEERING

engineering, however, the word has attained a far wider signification, and has been adopted in connexion with a consider-able variety of See also:

• HYDRAULIC

hydraulic See also:

• WORKS

works . A See also:

• CAISSON (from the Fr. caisse, the variant form " cassoon " being adapted from the Ital. casone)

caisson in this sense implies a case or enclosure of See also:

• WOOD, ANTHONY A2 (1632-1695)
• WOOD, JOHN GEORGE (1827—1889)
• WOOD, MRS HENRY [ELLEN] (1814—1887)
• WOOD, SEARLES VALENTINE (1798—188o)

wood or See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron, generally employed for keeping out See also:

• WATER

water during the See also:

• EXECUTION (from Lat. ex-sequor, exsecutus, follow or carry out)

execution of See also:

• FOUNDATIONS

foundations and other works in water-bearing strata, at' the See also:

• SIDE
• SIDE (mod. Eski Adalia)

side of or under See also:

• RIVERS
• RIVERS, ANTHONY WOODVILLE, or WYDEVILLE, 2ND EARL (c. 1442—1483)
• RIVERS, EARL
• RIVERS, RICHARD SAVAGE, 4TH EARL (c. 1660—1712)

rivers, and also in the See also:

• SEA (in O. Eng. sae, a common Teutonic word; cf. Ger. See, Dutch Zee, &c.; the ultimate source is uncertain)
• SEA, COMMAND OF THE

sea . There are two distinct forms of this type of caisson :—(t) A caisson open at the See also:

• TOP (cf. Dan. top, Ger. Topf, also meaning pot)

top, whose sides, when it'is sunk in position, emerge above the water-level, and which is either provided with a water-tight bottom or is carried down, by being weighted at the top and having a cutting edge See also:

• ROUND (O. Fr. rond, Lat. rotundus, the Fr. is the source also of Du. rond; Ger., Swed., Dan. and Nor. rond)

round the bottom, into a water-tight stratum, aided frequently by excavation inside; (2) A bottomless caisson, serving as a sort of diving-See also:

• BELL
• BELL, ALEXANDER MELVILLE (1819—1905)
• BELL, ANDREW (1753—1832)
• BELL, GEORGE JOSEPH (1770-1843)
• BELL, HENRY (1767-1830)
• BELL, HENRY GLASSFORD (1803-1874)
• BELL, JACOB (1810-1859)
• BELL, JOHN (1691-178o)
• BELL, JOHN (1763-1820)
• BELL, JOHN (1797-1869)
• BELL, ROBERT (1800-1867)
• BELL, SIR CHARLES (1774—1842)

bell, in which men can See also:

• WORK

work when compressed See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air is introduced to keep out the water in proportion to the See also:

• DEPTH

depth below the water-level, which is gradually carried down to an adequately See also:

• FIRM

firm See also:

• FOUNDATION (Lat. fundatio, from fundare, to found)

foundation by excavating at the bottom of the caisson, and See also:

• BUILDING

building up a See also:

• QUAY
• QUAY, MATTHEW STANLEY (1833-1904)

quay-See also:

• WALL (O. Eng. weal, weall, Mid. Eng. wal, wane, adapted from Lat. vallum, rampart; the original O. Eng. word for a wall was wag or tenth)
• WALL, RICHARD (1694-1778)

wall or See also:

• PIER (older forms per or Pere, from Med. Lat. pera; the word for piers out of water. For river piers, where a firm, watertight is of obscure origin, and the connexion with Fr. Pierre, Lat. stratum is found at a moderate depth below the river-bed, the pctr

pier out of water on the top of its roof as it descends . An example of a caisson with a water-tight bottom is furnished by the quays erected alongside the See also:

• SEINE
• SEINE (Lat. Sequana)
• SEINE, or SEAN (O. Fr. seigne, mod. seine, Lat. sagena, Gr. vaytivrl, a draw-net)

Seine at See also:

• ROUEN

Rouen, where open-See also:

• TIMBER

timber caissons were sunk on to bearing-piles down to a depth of 9; ft. below See also:

• LOW, SETH (1850- )
• LOW, WILL HICOK (1853- )

low-water, the See also:

• BRICK (derived according to some etymologists from the Teutonic bricke, a disk or plate; but more authoritatively, through the French brique, originally a " broken piece," applied especially to bread, and so to clay, from the Teutonic brikan, to break)

brick and See also:

• CONCRETE
• CONCRETE (Lat. concretes, participle of concrescere, to grow together)

concrete See also:

• LOWER

lower portions of the quay-wall being built inside them out of water (see Docx) . At See also:

• BILBAO

Bilbao, Zeebrugge and See also:

• SCHEVENINGEN

Scheveningen harbours, large open See also:

• METAL
• METAL (through Fr. from Lat. metallum, mine, quarry, adapted from Gr. µATaXAov, in the same sense, probably connected with ,ueraAAdv, to search after, explore, µeTa, after, aAAos, other)

metal caissons, built inland, ballasted with concrete, floated out into position, and then sunk and filled with concrete, have been employed for forming very large foundation blocks for the breakwaters (see See also:

• BREAKWATER

BREAKWATER) . Open iron caissons are frequently employed for enclosing the site of See also:

• RIVER

river piers for See also:

• BRIDGES
• BRIDGES, ROBERT (1844– )

bridges, where a water-tight stratum can be reached at a moderate depth, into which the caisson can be taken down, so that the water can be pumped out of the enclosure and the foundations laid and the pier carried up in the open air . Thus the two large river piers carrying the high towers, bascules, and machinery of the See also:

• TOWER (Lat. turris; Fr. tour, clocker; Ital. torre; Ger. Thurm)

Tower See also:

• BRIDGE

Bridge, See also:

• LONDON

London, were each founded and built within a See also:

• GROUP

group of twelve See also:

• PLATE

plate-iron caissons open at the top; whilst four of the piers on which the cantilevers of the Forth Bridge See also:

• REST (O. Eng. rest, reste, bed, cognate with other Teutonic forms, e.g. Ger. Rast, Riiste, rest, and probably Gothic Rasta, league, i.e. resting or stopping place)

rest, were each erected within an open plate-iron caisson fitted at the bottom to the sloping See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock, where See also:

• ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

ordinary cofferdams could not have been adopted . Where foundations have to be carried down to a considerable depth in water-bearing strata, or through the alluvial See also:

• BED
• BED (a common Teutonic word, cf. German Bett, probably connected with the Indo-European root bhodh, seen in the Lat. fodere, to dig; so " a dug-out place " for safe resting, or in the same sense as a garden " bed ")

bed of a river, to reach a hard stratum, bottomless caissons sunk by excavating under compressed air are employed . The caisson at the bottom, forming the working chamber, is usually provided with a strong roof, round the top of which, when the caisson is floated into a river, plate-iron sides are erected forming an upper open caisson, inside which the pier or quay-wall is built up out of water, on the top of the roof, as the sinking proceeds . Shafts through the roof up to the open air provide See also:

• ACCESS (Lat. accessus)

access for men and materials to the working chamber, through an air-See also:

• LOCK (from the O. Eng. loc.; the word appears, in different forms, in many Teutonic languages, but with such various meanings as " hole," Ger. Loch, " lid," Swed. lock, &c.; probably the original was a root meaning " to enclose ")
• LOCK, MATTHIAS

lock consisting of a small chamber with an air-tight See also:

• DOOR (corresponding to the Gr. Bbpa,. Lat. fores or valvae; the English word, with other forms common in allied languages, comes from the same Indo-European stem as the Gr. Obpa and Lat. fares)

door at each end, enabling locking into and out of the compressed-air portion to be readily effected, on the same principle as a water-lock on a See also:

• CANAL
• CANAL (from Lat. canalis, " channel " and " kennel " being doublets of the word)

canal .

When a sufficiently reliable stratum has been reached, the men leave the working chamber; and it is filled with concrete through the shafts, the bottomless caisson remaining embedded in the work . The foundations for the two river piers of the See also:

• BROOKLYN

Brooklyn Suspension Bridge, carried down to the solid rock, 78 and 45 ft. respectively below high-water, by means of bottomless timber caissons with compressed air, were an See also:

• EARLY
• EARLY, JUBAL ANDERSON (1816-1894)

early instance of this method of carrying out subaqueous foundations; whilst the See also:

• ANTWERP
• ANTWERP (Fr. Anvers)

Antwerp quay-walls, commenced many years ago in the river See also:

• SCHELDT (Fr. Escaut, Flem. Schelde)

Scheldt at some distance out from the right See also:

• BANK

bank, and the foundations of six of the piers supporting the cantilevers of the Forth Bridge, carried down to rock between 64 and 89 ft. below high-water, are notable examples of works founded under water within wrought iron bottomless caissens by the aid of compressed air . The foundations of the two piers of the Eiffel Totver adjoining the Seine were carried down through soft water-bearing strata to a depth of 33 ft. by means of wrought iron bottomless caissons sunk by the help of compressed air; and the deep foundations under the sills of the new large See also:

• FLORIDA

Florida lock at See also:

• HAVRE
• HAVRE, LE

Havre (see Doc() were laid underneath the water logged alluvial strata See also:

• CLOSE
• CLOSE (from Lat. clausum, shut)
• CLOSE, MAXWELL HENRY (1822-1903)

close to the Seine See also:

• ESTUARY (from the Lat. aestuarium, a place reached by aestus, the tide)

estuary by similar means . Workmen, after emerging from'such caissons, sometimes exhibit symptoms of illness which is known as caisson disease (q.v.) . As in the above See also:

• SYSTEM

system, significantly termed by Frenchengineers See also:

• PAR (Lat. par, equal)

par caisson perdu, the materials of the bottomless caisson have to be See also:

• LEFT

left in the work, a more economical system has been adapted for carrying out similar foundations, at moderate depths, by using movable caissons, which, after the lowest portions of the foundations have been laid, are raised by See also:

• SCREW (O.E. scrue, from O. Fr. escroue, mod. ecrou; ultimate origin uncertain; the word, or a similar one, appears in Teutonic languages, cf. Ger. Schraube, Dan. skrue, but Skeat, following Diaz, finds the origin in Lat. scrobs, a ditch, hole, particularl

screw-jacks for constructing the next portions . In this way, instead of building the pier or wall on the roof of the caisson, the work is carried out under water in successive stages, by raising the bottomless caisson as the work proceeds; and by this arrangement, the caisson, having completed the subaqueous portion of the structure, is available for work elsewhere . This movable system has been used with See also:

• ADVANTAGE

advantage for the foundations for some piers of river bridges, some breakwater foundations, and, at the Florida lock, Havre, for See also:

• FOUNDING (from Lat. fundere, to pour)

founding portions of the side walls . Closed iron caissons, termed See also:

• SHIP

ship-caissons, and sliding or See also:

• ROLLING

rolling caissons, are generally employed for closing graving-docks, especially the former (so called from their resemblance in shape to a See also:

• VESSEL (O. Fr. vaissel, from a rare Lat. vascellum, dim. of vas, vase, urn)

vessel) on See also:

• ACCOUNT
• ACCOUNT (through O. Fr. acont, Late Lat. comptum, cornputare, to calculate)

account of their simplicity, being readily floated into and out of position; whilst sliding caissons are sometimes used instead of lock-See also:

• GATES, HORATIO (1728-1806)

gates at docks, but require a chamber at the side to receive them when See also:

• DRAWN

drawn back . They possess the ad-vantage, particularly for See also:

• NAVAL

naval See also:

• DOCKYARDS

dockyards where heavy weights are transported, of providing in addition a strong movable bridge, thereby dispensing with a See also:

• SWING, DAVID (1830-1894)

swing-bridge across the opening . The term caisson is sometimes applied to See also:

• FLAT (a modification of O. Eng. flet, an obsolete word of Teutonic origin, meaning the ground beneath the feet)

flat air-tight constructions used for raising vessels out of water for cleaning or See also:

• REPAIRS (from Lat. reparare, to make ready again)

repairs, by being sunk under them and then floated; but these floating caissons are more commonly known as pontoons, or, when air-See also:

• CHAMBERS (the Fr. chambre, from Lat. camera, a room)
• CHAMBERS, EPHRAIM (d. 1740)
• CHAMBERS, GEORGE (1803-1840)
• CHAMBERS, ROBERT (18oz-1871)
• CHAMBERS, SIR WILLIAM (1726-1796)

chambers are added at the sides, as floating dry-docks . (L . F .