See also:

• COKE (a northern English word, possibly connected with " colk," core)
• COKE, SIR EDWARD (1552-1634)
• COKE, SIR JOHN (1563-1644)
• COKE, THOMAS (1747-1814)

COKE (a See also:

• NORTHERN

northern See also:

• ENGLISH

English word, possibly connected with " colk," core)  , the product obtained by strongly See also:

• HEATING

heating See also:

• COAL

coal out of contact with the See also:

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

air until the volatile constituents are driven off; it consists essentially of See also:

• CARBON (symbol C, atomic weight 12)

carbon, the so-called " fixed carbon," together with the incombustible matters or ash contained in the coal from which it is derived . In addition to these it almost invariably contains small quantities of See also:

• HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen, See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen and See also:

• NITROGEN [symbol N., atomic weight 14.01, 0=16]

nitrogen, the whole, however, not exceeding 2 or 3% . It also contains See also:

• WATER

water, the amount of which may vary considerably according to the method of manufacture . When produced rapidly and at a See also:

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

low See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

heat, as in See also:

• GAS

gas-making, it is of a dull See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour, and a loose spongy or See also:

• PUMICE (Lat. purnex, spumex, spuma, froth)

pumice-like texture, and ignites with See also:

• COMPARATIVE

comparative ease, though less readily than bituminous coal, so that it may be burnt in open See also:

• FIRE (in O. Eng. f j'r; the word is common to West German languages, cf. Dutch vuur, Ger. Feuer; the pre-Teutonic form is seen in Sanskrit pu, pavaka, and Gr. irup; the ultimate origin is usually taken to be a root meaning to purify, cf. Lat. purus)

fire-places; but when a See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long-continued heat is used, as in the preparation of See also:

• COKE (a northern English word, possibly connected with " colk," core)
• COKE, SIR EDWARD (1552-1634)
• COKE, SIR JOHN (1563-1644)
• COKE, THOMAS (1747-1814)

coke for See also:

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

iron and See also:

• STEEL, FLORA ANNIE (1847– )

steel melting, the 'product is hard and dense, is often prismatic in structure, has a brilliant semi-metallic lustre and silvery-See also:

• GREY, CHARLES GREY, 2ND EARL (1764-1845)
• GREY, HENRY GREY, 3RD EARL (1802-1894)
• GREY, LADY JANE (1537-1554)
• GREY, SIR EDWARD
• GREY, SIR GEORGE (1812–1898)

grey colour, is a conductor of heat and See also:

• ELECTRICITY

electricity, and can only be burnt in furnaces provided with a strong See also:

• CHIMNEY (through the Fr. cheminee, from caminata, sc. camera, a Lat. derivative of caminus, an oven or furnace)

chimney See also:

• DRAUGHT (from the common Teutonic word " to draw "; cf. Ger. 7'racht, load; the pronunciation led to the variant form " draft," now confined to certain specific meanings)

draught or an artificial blast . The strength and cohesive properties are also intimately related to the nature and See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition of the coals employed, which are said to be caking or non-caking according to the compact or fragmentary See also:

• CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

character of the coke produced . Formerly coke was made from large coal piled in heaps with central chimneys like those of the See also:

• CHARCOAL

charcoal burner, or in open rectangular clamps or kilns with air flues in the enclosing walls; but these methods are now practically obsolete, closed 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 or ovens being generally used . These vary considerably in construction, but may be classified into three See also:

• PRINCIPAL

principal types:-(1) See also:

• DIRECT

direct heated ovens, (2) flue-heated ovens, (3) condensing See also:

• OVEN (O. Eng. of n,Ger. Ofen, cf. Gr. Irvin, oven)

oven. circular hole at the See also:

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

top . The See also:

• FLOOR (from O. Eng. flor, a word common to many Teutonic languages, cf. Dutch vloer, and Ger. Flur, a field, in the feminine, and a floor, masculine)

floor, made of refractory bricks or slabs, is laid with a slight slope towards an arched opening in the See also:

• RING (O.E. hring; a word common to Teutonic languages; and probably cognate with the Lat. circus, Gr. KtpKOS or KpLKOS, Skt'. chakra, wheel, circle, cf. also " harangue "); in art, a band of circular shape of varying sizes, made of any material and used f

ring 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, which is stopped with See also:

• BRICKWORK

brickwork during the coking but opened for See also:

• DRAWING

drawing the finished See also:

• CHARGE
• CHARGE (through the Fr. from the Late Lat. carricare, to load in a carrus or wagon; cf. " cargo ")

charge . The ovens are usually arranged in rows or See also:

• BANKS, GEORGE LINNAEUS (1821-1881)
• BANKS, NATHANIEL PRENTISS (1816–1894)
• BANKS, SIR JOSEPH
• BANKS, THOMAS (1735-1805)

banks of 20 to 30 or more, with their doors outwards, two rows being often placed with a See also:

• LONGITUDINAL

longitudinal flue between them connected by uptakes with the individual ovens on either See also:

• SIDE
• SIDE (mod. Eski Adalia)

side . A railway along the top of the See also:

• BANK

bank brings the coal from the screens or washery . The largest ovens take a charge of about 5 tons, which is introduced through the hole in the roof, 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-See also:

• WORK

work of the empty oven being still red hot from the preceding charge, and when levelled fills the cylindrical See also:

• PART

part nearly to the springing of the roof . The gas fires as it is given off and fills the See also:

• DOME (Lat domus, house; Ital. duomo, cathedral)

dome with See also:

• FLAME (Lat. flamma; the root flag- appears in flagrare, to burn, blaze, and Gr. d, XEryew)

flame, and the burning is regulated by air admitted through holes in the upper part of the 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 stopping .

The temperature being very high, a proportion of the volatile See also:

• HYDROCARBONS

hydrocarbons is decomposed, and a film of graphitic carbon is deposited on the coke, giving it a semi-metallic lustre and silvery grey colour . When the gas is burned off, the upper part of the door is opened and the glowing charge cooled by jets of water thrown directly upon it from a See also:

• HOSE (a word common to many Teutonic languages; cf. Dutch, hoes, stocking, Ger. Hose, breeches, tights; the ultimate origin is unknown)

hose, and it is subsequently See also:

• DRAWN

drawn out through the open door . The charge breaks up into prisms or columns whose length corresponds to the See also:

• DEPTH

depth of the charge, and as a See also:

• RULE

rule is See also:

• UNIFORM

uniform in character and See also:

• FREE

free from dull black patches or " black ends." The See also:

• TIME (0. Eng. Lima, cf. Icel. timi, Swed. timme, hour, Dan. time; from the root also seen in " tide," properly the time of between the flow and ebb of the sea, cf. O. Eng. getidan, to happen, " even-tide," &c.; it is not directly related to Lat. tempus)
• TIME, MEASUREMENT OF
• TIME, STANDARD

time of burning is either 48 or 72 See also:

• HOURS, CANONICAL

hours, the turns being so arranged as to avoid the See also:

• NECESSITY (Lat. necessitas)

necessity of drawing the ovens on See also:

• SUNDAY

Sunday . The longer the heat is continued the denser the product becomes, but the yield also diminishes, as a portion of the finished coke necessarily See also:

• BURNS, JOHN (1858– )
• BURNS, ROBERT (1759-1796)
• BURNS, SIR GEORGE

burns to See also:

• WASTE (O. Fr. wast, guast, gast, gaste; Lat. vastus, vast, desolate)

waste when the gas is exhausted . For this See also:

• REASON (Lat. ratio, through French raison)

reason the yield on the coal charged is usually less than that obtained in See also:

• RETORT (Lat. retorquere, to twist or turn back)

retort ovens, although the quality may be better . Coals containing at most about 35% of volatile See also:

• MATTER

matter are best suited for the beehive oven . With less than 25% the gas is not sufficient to effect the coking completely, and when there is a higher percentage the coke is brittle and spongy and unsuited for blast See also:

• FURNACE

furnace or foundry use . The spent flame from the ovens passes to a range of See also:

• STEAM
• STEAM (0. Eng. steam, vapour, smoke, cf. Du. steam; the origin is unknown)

steam boilers before escaping by the chimney . The retort oven, which is now generally displacing the beehive See also:

• FORM (Lat. forma)

form in new installations, is made in a See also:

• GREAT

great variety of forms, the Retort See also:

• DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences being mainly in the arrangement of the heating flues, but all have the central feature, the coking oven. chamber, in See also:

• COMMON

common . This is a tubular chamber with See also:

• VERTICAL (from Lat. vertex, highest point)

vertical sides and cylindrical roof, about 30 ft. long, from 17 to 20 in. wide, and 6 or 7 ft. high, and closed at both ends by sliding doors which are raised by crab winches when the charge is to be drawn . The See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general arrangements of such an oven are shown in fig. i, which represents one of the earliest and most popular forms, that of Evence See also:

• COPPEE, FRANCOIS EDOUARD JOACHIM (1842—1908)
• COPPEE, HENRY (1821-1895)

Coppee of See also:

• BRUSSELS (Fr. Bruxelles, Flem. Brussel)

Brussels . The coking chambers A B connect by rectangular posts at the springing of the roof, where the gas given off from the top of the charge is fired by air introduced through c c .

The flames pass downwards through the parallel flues f f along the bottom flue of one oven, and return in the opposite direction under the next to the chimney flue, a further part of the heat being intercepted by placing a range of steam boilers between the ovens and the chimney stack . The charging of the oven is done through the passages D D in the roof from small wagons on transverse lines of rails, the See also:

• SURFACE

surface being raked level before the doors are closed and luted up . The time of coking is much less than in the beehive ovens and may be from 24 to 36 hours, according to the proportion of volatile matter See also:

• PRESENT

present . When the gas is completely given off the doors are lifted and the charge is pushed out by the See also:

• RAM
• RAM, PIERRE FRANCOIS XAVIER DE (18o4-1865)

ram—a See also:

• CAST (from the verb meaning " to throw "; the word is Scand. in origin, cf. Dan. kaste, and Swed. kasta; " cast " in Middle Eng. took the place of the A.S. weor pan, cf. Ger. werf en)

cast-iron See also:

• PLATE

plate of the shape of the See also:

• CROSS

cross See also:

• SECTION
• SECTION (Lat. sectio, cutting, secare, to cut)

section of the oven, at the end of a long See also:

• HORIZONTAL

horizontal See also:

• BAR
• BAR (0. Fr. barre, Late Lat. barra, origin unknown)
• BAR, CONFEDERATION OF
• BAR, FRANCOIS DE (1538-1606)
• BAR, THE

bar, which is driven by a See also:

• RACK

rack and pinion See also:

• MOVEMENT

movement and pushes the See also:

• BLOCK
• BLOCK (from the Fr. bloc, and possibly connected with an Old Ger. Block, obstruction, cf. " baulk ")
• BLOCK, MAURICE (1816–19or)

block of coke out of the oven on to the See also:

• WHARF

wharf or bank in front where it falls to pieces and is immediatelyquenched by jets of water from a hose See also:

• PIPE

pipe . When sufficiently cooled it is loaded into railway wagons or other conveyances for removal . The ram, together with its motor, and See also:

• BOILER

boiler when steam is used, is mounted upon a See also:

• CARRIAGE

carriage See also:

• RUNNING

running upon a See also:

• LINE

line of rails of about 2 ft. See also:

• GAUGE, or GAGE (Med. Lat. gauja, jaugia, Fr. jauge, perhaps connected with Fr. jale, a bowl, galon, gallon)

gauge along the back of the range of ovens, so that it can be brought up to any one of them in See also:

• SUCCESSION (Lat. successio, from succedere, to follow after)

succession . In some cases, instead of the small coal being charged through the roof of the oven and levelled by See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand, it is formed into blocks by being stamped in a slightly moistened See also:

• CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition in a See also:

• MOULD

mould consisting of a bottom plate or See also:

• PEEL
• PEEL, ARTHUR WELLESLEY PEEL, 1ST VISCOUNT (1829- )
• PEEL, SIR ROBERT, BART

peel on a racked See also:

• ROD (O.E. rodd, probably related to Norw. rudda, stick, rodda, stake)
• ROD, EDOUARD (1857-1910)

rod like that of the ram, with movable sides and ends . This, when the ends are removed, is pushed forward into the oven, and the bottom plate is withdrawn by See also:

• REVERSING

reversing the rack See also:

• MOTION (Lat. motio, from movere, to move)
• MOTION, LAWS OF

motion . The moulding See also:

• BOX
• BOX (Gr. irl or, Lat. buxus, box-wood; cf. 2r6Eir, a pyx)

box is mounted on a carriage like that of the ram, the two being sometimes carried on the same framing . The moulding is done at a fixed station in the centre of the range of ovens by a See also:

• SERIES (a Latin word from serere, to join)

series of cast-iron stampers driven by an electric motor . This See also:

• SYSTEM

system is useful for coals low in volatile matter, which do not give a coherent coke under See also:

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

ordinary conditions . In the distilling or by-product ovens the gases, instead of being burned at the point of origin, pass by an uptake pipe in the roof about the centre of the oven into a water-sealed See also:

• COLLECTING

collecting trough or See also:

• HYDRAULIC

hydraulic See also:

• MAIN (from the Aryan root which appears in " may " and " might," and Lat. magnus, great)
• MAIN (Lat. Moenus)

main, whence they are drawn by Condensexhausters through a series of air and water cooled See also:

• CON

con- ingovens. densers and scrubbers .

In the first or atmospheric condensers the See also:

• TAR

tar is removed, and in the second ammoniacal water, which is further enriched by a graduated system of scrubbing with weak ammoniacal liquor until it is sufficiently concentrated to be sent to the See also:

• AMMONIA (NH3)

ammonia stills . The first treatment by scrubbing with See also:

• CREOSOTE, CREASOTE

creosote or heavy tar oil removes See also:

• BENZENE, C6H6

benzene, after which the permanent gaseous See also:

• RESIDUE (through the French, from the Lat. residuum, a remainder, from residere, to remain)

residue consisting chiefly of hydrogen and See also:

• MARSH (O. F. mersc, for merisc, a place full of "meres" or pools; cf. Ger. Meer, sea, Lat. mare)
• MARSH, ADAM (ADAM DE MARISCO) (d. c. 1258)
• MARSH, GEORGE PERKINS (1801-1882)
• MARSH, HERBERT (1757–1839)
• MARSH, NARCISSUS (1638-1713)
• MARSH, OTHNIEL CHARLES (1831-1899)

marsh gas is returned to the ovens as See also:

• FUEL (O. Fr. feuaile, popular Lat. focalia, from focus, hearth, fire)

fuel . In the See also:

• OTTO

Otto-See also:

• HOFFMANN, AUGUST HEINRICH (1798–1874)
• HOFFMANN, ERNST THEODOR WILHELM (1776-1822)
• HOFFMANN, JOHANN JOSEPH (1805-1878)

Hoffmann oven, one of the most generally used forms, vertical side flues like those of Coppee are adopted . The returned gas enters by a horizontal flue along the bottom of the coking chamber, divided into two parts by a See also:

• MID

mid-See also:

• FEATHER (0. Eng. (ether, Ger. Feder, from an Indo-European root seen also in Gr. lrrepov, and aEreo-Oat, to fly)

feather wall, and is fired by heated air from a See also:

• SIEMENS, ERNST WERNER VON (1816-1892)
• SIEMENS, SIR WILLIAM [KARL WILHELM] (1823-1883)

Siemens regenerator on the substructure at one end, and the flame rising through one See also:

• HALF

half of the side flues to a parallel See also:

• COLLECTOR

collector at the top returns downwards through the flues of the other half and passes out to the chimney through a similar regenerator at the other end . The course of the gases is reversed at intervals of about an See also:

• HOUR

hour, as in the ordinary Siemens furnace. each end of the oven having its own gas See also:

• SUPPLY (through Fr. from Lat. supplere, to fill up)

supply . In the later modification known as the Otto-Hilgenstock, the regenerators are abandoned, but See also:

• PROVISION (Lat. provisio)

provision is made for more perfect See also:

• DISTRIBUTION (Lat. distribuere, to deal out)

distribution of the heat by a line of sixteen See also:

• BUNSEN, CHRISTIAN CHARLES JOSIAS, BARON VON (1791-186o,)
• BUNSEN, ROBERT WILHELM VON (1811-1899)

Bunsen burners in each wall; each of these serves two flues, the course of the flame being continuously upwards without reversal . In the newest Otto ovens the same system of burners is combined with regenerators . In the See also:

• BAUER, BRUNO (1809-1882)

Bauer system, another vertical flue oven, each flue has its own burner, which is of a simplified construction . In the Carves oven, the earliest of the by-product ovens, the heating flues are arranged horizontally in parallel series along the entire length of the side walls, the gas being introduced from both ends but at different levels . This system was further See also:

• DEVELOPED

developed by H . See also:

• SIMON, ABRAHAM (1622-1692)
• SIMON, JULES FRANCOIS (1814–1896)
• SIMON, RICHARD (1638–1712)
• SIMON, SIR JOHN (1816–1904)
• SIMON, THOMAS (c. 1623-1665)

Simon of See also:

• MANCHESTER
• MANCHESTER (popularly Manchester-by-the-Sea)
• MANCHESTER, EARLS AND DUKES OF

Manchester, who added a continuous air " recuperator " heated by the spent flame; this Simon-Carves system has been extensively adopted in Great See also:

• BRITAIN (Gr. Hperavuml vi7vot, Bperravia; Lat. Britannia, rarely Britannia)

Britain . Another horizontal flue oven, the Semet-Solvay, is distinguished by the structure of the flues, which are See also:

• INDEPENDENT

independent of the dividing walls of the ovens, so that the latter can be made with thinner sides than those of the earlier systems, and are more readily repaired .

In the horizontal ovens it is sometimes difficult to maintain the heat when the flues are continuous along the whole length of the wall, especially when the heating value of the gas is reduced by the removal of the heavy hydrocarbons . This difficulty is met by dividing the flues in the See also:

• MIDDLE

middle so as to shorten the length of travel of the flame, and working each end independently . The Hiissener and Koppers systems are two of the best-known examples of this modification . Coke from retort ovens is not so dense or brilliant as that made Longitudinal Seetion D Seeps, o•A ir~to rcwnsnaeaseae— figi:,..• a * yioniav000~ir mvimioc/~wan : sic \WM, Transverse Section C C C C c chimney t«e _ mve . /ahMM=1917AW .umi® iPmn f~\F1\'' .Val &ma& aro-eonau a ovens . In the first class the heating is done by direct contact or by burning the gases given off in coking within the oven, while in the other two the heating is indirect, the gas being burned in cellular passages or flues provided in the walls dividing the coking chambers, and the heat transmitted through the sides of the latter which are comparatively thin . The arrangement is somewhat similar to that of a gas-See also:

• WORKS

works retort, whence the name of " retort ovens " is sometimes applied to them . The difference between the second and third classes is founded on the treatment of the gases . In the former the gas is fired in the side flues immediately upon issuing from the oven, while in the latter the gases are first subjected to a systematic treatment in condensers, similar to those used in gas-works, to remove tar, ammonia and condensable hydrocarbons, the incondensable gases being returned to the oven and burned in the heating flues . These are generally known as " by-product ovens." The simplest form of coke oven, and probably that still most largely used, is the so-called " beehive oven." This is circular in See also:

• PLAN
• PLAN (from Lat. planes, flat)

plan, from 7 to 12 ft. in See also:

• DIAMETER (from the Cr. &a, through, µErpov, measure)

diameter, with a cylindrical wall Beehive about 21 ft. high and a nearly hemispherical roof with a in beehive ovens, but the waste being less there is a decided saving, apart from the value of the condensed products . In one instance the coke was found to be about 5 % less efficient in the blast furnace, while the yield on the coal charged was increased 10 % . In the further treatment of the condensed products by See also:

• DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation the tar gives burning oil and See also:

• PITCH
• PITCH, MUSICAL

pitch, the benzene is separated from the creosote oil by steam-heated stills, and the ammoniacal liquor, after some See also:

• LIME
• LIME (O. Eng. lim, Lat. limes, mud, from linere, to smear)

lime has been added to decompose fixed ammonium compounds, is heated to vaporize the ammonia, which is condensed in See also:

• LEAD
• LEAD (pronounced iced)

lead or See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper-lined tanks containing strong sulphuric See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid to produce a crystalline See also:

• POWDER (through O. Fr. puldre, modern poudre, from Lat. pulvis, pulveris, dust)

powder of ammonium sulphate, which accumulates in the See also:

• RECEIVER

receiver and is fished out from time to time .

The yield of by-products averages about i % of ammonium sulphate, about 31% of tar, and o•6 to 0.9 % of benzene, of the See also:

• WEIGHT

weight of the coal carbonized . After the ovens have been heated and steam supplied for the machinery of the condensing plant and the coke ovens, there is usually a surplus of gas, which may be used for See also:

• LIGHTING

lighting or See also:

• DRIVING (from " to drive," i.e. generally to propel, force along or in, a word common in various forms to the Teutonic languages)

driving gas-engines . For the latter purpose, however, it is necessary to remove the last traces of tar, which acts very prejudicially in fouling the valves when the gas is not completely purified . The gas given off during the earlier part of the coking See also:

• PROCESS

process is richer in heavy hydrocarbons and of a higher See also:

• ILLUMINATING

illuminating value than that of the later See also:

• PERIOD
• PERIOD (Gr. irepioSos, a going or way round, circuit, aepi, round, and &Sis, way, road)

period when the temperature is higher . This See also:

• PROPERTY

property is utilized in several large coking See also:

• PLANTS

plants in See also:

• AMERICA

America, where the gas from the first ten hours' working is drawn off by a second hydraulic main and sent directly to See also:

• TOWN

town gas-works, where it passes through the ordinary purifying treatment, the gas from the second period being alone used for heating the ovens . Coke is essentially a partially graphitized carbon, its See also:

• DENSITY (Lat. densus, thick)

density being about midway between that of coal and See also:

• GRAPHITE

graphite, and it should therefore occupy less space than the See also:

• ORIGINAL

original coal; but owing to the softening of the charge a spongy structure is set up by the escaping gases, which acts in the other direction, so that for equal bulk coke is somewhat lighter than coal . It is this See also:

• COMBINATION (Lat. combinare, to combine)

combination of properties that gives it its See also:

• CHIEF (from Fr. chef, head, Lat. caput)

chief value in iron smelting, the substance being sufficiently dense to resist oxidation by carbon dioxide in the higher regions of the furnace, while the vesicular structure gives an extended surface for the See also:

• ACTION

action of heated air and facilitates rapid See also:

• CONSUMPTION (Lat. consumere)

consumption at the tuyeres . Compact coke, such as that formed on the inner sides of gas retorts (retort carbon), can only be burned with great difficulty in small furnaces of See also:

• SPECIAL

special construction, but it gives out a great amount of heat . The most deleterious constituents of coke are ash, See also:

• SULPHUR

sulphur and volatile constituents including water . As the coke yield is only from two-thirds to three-quarters of that of the coal, the original proportion of ash is augmented by one-third or one-half in the product . For this reason it is now customary to crush and See also:

• WASH, THE

wash the coal carefully to remove intermingled patches of shale and dirt before coking, so that the ash may not if possible exceed le% in the coke . About one-half of the sulphur in the coal is eliminated in coking, so that the percentage in the coke is about the same .

It should not be much above 1 % . According to the researches of F . Wuest (Journ . Iron and Steel Inst., 1go6) the sulphur is retained in a complex carbon See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound which is not destroyed until the coke is actually consumed . The older methods of coking and the earlier forms of retort ovens are described in J . See also:

• PERCY (FAMILY)
• PERCY, SIR HENRY
• PERCY, THOMAS (1729-1811)
• PERCY, THOMAS (c. 156o-16os)

Percy, Metallurgy, See also:

• JORDAN (the down-comer; Arab. esh-Sheri'a, the watering-place)
• JORDAN, CAMILLE (1771—1821)
• JORDAN, DOROTHEA (1762—1816)
• JORDAN, THOMAS (1612 ?–1685)
• JORDAN, WILHELM (1819–1904)

Jordan, See also:

• ALBUM (Lat. albus, white)

Album du See also:

• TOURS

tours de metallurgie . See also:

• PHILLIPS
• PHILLIPS, ADELAIDE (1833-1882)
• PHILLIPS, EDWARD (163o-1696)
• PHILLIPS, JOHN (1800—1874)
• PHILLIPS, SAMUEL (1814—1854)
• PHILLIPS, STEPHEN (1868– )
• PHILLIPS, THOMAS (1770-1845)
• PHILLIPS, WENDELL (1811-1884)

Phillips and Bauerman, Handbook of Metallurgy, and other See also:

• TEXT (Lat. textum, woven fabric, from texere, to weave)

text-books . A systematic series of articles on the newer forms will be found in The Engineer, vol . 82, pp . 205-303 and vol . 83, pp . 207-231; see also Durre, See also:

• DIE
• DIE (Fr. de, from Lat. datum, given)

Die neuern Koksofen (See also:

• LEIPZIG

Leipzig, 1892) ; D .

A . See also:

• LOUIS
• LOUIS (804–876)
• LOUIS (893–911)
• LOUIS, JOSEPH DOMINIQUE, BARON (1755-1837)
• LOUIS, or LEWIS (from the Frankish Chlodowich, Chlodwig, Latinized as Chlodowius, Lodhuwicus, Lodhuvicus, whence-in the Strassburg oath of 842-0. Fr. Lodhuwigs, then Chlovis, Loys and later Louis, whence Span. Luiz and—through the Angevin kings—Hungarian

Louis, " Von Bauer and Briinck Ovens," Journ . Iron and Steel Inst., 1904, ii. p . 293; C . L . 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, " Hiissener Oven," id., 1904, i. p . 188; Hurez, " A Comparison of Different Systems of Vertical and Horizontal Flue Ovens," See also:

• BULL
• BULL, GEORGE (1634–1710)
• BULL, JOHN (c. 1562–1628)
• BULL, OLE BORNEMANN (18ro-188o)

Bull. See also:

• SOC

soc. industrie minerale, 1903, p . 777 . A well-illustrated description of the Otto system in its See also:

• AMERICAN

American modification was issued by the See also:

• UNITED

United Gas & Coke See also:

• COMPANY

Company of New See also:

• YORK
• YORK (HOUSE OF)
• YORK, EDMUND OF LANGLEY, DUKE OF (1341-1402)
• YORK, EDWARD
• YORK, FREDERICK AUGUSTUS, DUKE OF (1763-1827)
• YORK, RICHARD, DUKE

York, in 1906 . (H .