« ՆախորդըՇարունակել »
products of the destructive distillation of the coal, &c., are known much of the waste heat can be utilized for a preliminary heating as producer gas or Siemens gas. In the second case the chemical of the air and the gas to be burned by means of "recuperators.” reaction is mainly
We shall now describe the principal classes of gaseous fuel, C+H2O=CO+H;
(6); produced by the partial combustion of coal. that is to say, the carbon is converted into monoxide and the A. Producer Gas, Siemens Gas.--As we have seen above, this hydrogen is set free. As both of these substances can combine gas is made by the incomplete combustion of fuel. The materials with oxygen, and as there is no atmospheric nitrogen to deal generally employed for its production are anthracite, coke or with, the resulting gas (water gas) is, apart from a few impurities, other fuels which are not liable to cake during the operation, entirely combustible. Another kind of water gas is formed by and thus stop the draught or otherwise disturb the process, but the reaction
by special measures also bituminous coal, lignite, peat and other C+2H,0=CO, 2H
fuel may be utilized for gas producers. The fuel is arranged in but this reaction, which converts all the carbon into the incom- a deep layer, generally from 4 st. up to 10 ft., and the air is bustible form of CO2, is considered as an unwelcome, although introduced from below, either by natural draught or by means of never entirely avoidable, concomitant of (6).
a blast, and either by a grate or only by a slit in the wall of the The reaction by which water gas is produced being endothermic gas producer.”. Even if the primary action taking place at (as we shall see),this gas cannot bc obtained except by introducing the entrance of the air consisted in the complete combustion of the balance of energy in another manner. This might be done the carbon to dioxide, CO2, the latter, in rising through the high by heating the apparatus from without, but as this method would column of incandescent fuel, must be reduced to monoxide: be uneconomical, the process is carried out by alternating the CO:+C=2C0. But as the temperature in the producer rises endothermic production of water gas with the exothermic rather high, and as in ordinary circumstances the action of combustion of carbon by atmospheric air. Pure water gas is oxygen on carbon above 1000° C. consists almost entirely in not, therefore, made by a continuous process, but alternates the direct formation of Co, we may regard this compound as with the production of other gases, combustible or not. But primarily formed in the hotter parts of the gas-producer. It is instead of constantly interrupting the process in this way, a true that ordinary producer gas always contains more or less continuous operation may be secured by simultaneously carrying CO2, but this may be formed higher up by air.entering through on both the reactions (a) and (b) in such proportions that the heat leakages in the apparatus. If we ignore the hydrogen contained generated by (a) at least equals the heat absorbed by (6). For in the fuel, the theoretical composition of producer gas would this purpose the apparatus is fed at the same time with atmo-be 33.3% CO and 66.7% N, both by volume and weight. Its spheric air and with a certain quantity of steam, preferably weight per cubic metre is 1.251 grammes, and its heat value 1013 in a superheated state. Gaseous mixtures of this kind have been calories per cubic metre, or less than one-fifth of the heat-value made, more or less intentionally, for a long time past. One of of coal gas. Practically, however, producer gas contains a small the best known of them, intended less for the purpose of serving percentage of gases, increasing its heat-value, like hydrogen, as ordinary fuel than for that of driving machinery, is the methane, &c., but on the other hand it is never free from carbon Dowson gas.
dioxide to the extent of from 2 to 8%. Its heat-value may An advantage common to all kinds of gaseous fuel, which therefore range between 800 and 1100 calories per cubic metre. indeed forms the principal reason why it is intentionally pro- Even when taking as the basis of our calculation a theoretical gas duced from solid fuel, in spite of inevitable losses in the course of 33.3 % CO, we find that there is a great loss of heat-value in of the operation, is the following. The combustion of solid fuel the manufacture of this gas. Thermochemistry teaches us that (coal, &c.) cannot be carried on with the theoretically necessary the reaction C+0 develops 29.5% of the heat produced by the quantity of atmospheric air, but requires a considerable excess complete oxidation of C to CO2, thus leaving only 70.5% for of the latter, at least 50%, sometimes 100% and more. This is the stage Co+0=CO,. II, therefore, the gas given off in the best seen from the analyses of smoke gases. If all the oxygen producer is allowed to cool down to ordinary temperature, of the air were converted into CO, and H.0, the amount of CO2 nearly 30% of the heat-value of the coal is lost' by radiation. in the smoke gases should be in the case of pure carbon nearly 1f, however, the gas producer is built in close proximity to the 21 volumes %, as carbon dioxide occupies the same volume as place where the combustion takes place, so that the gas does not oxygen; while ordinary coal, where the hydrogen takes up a lose very much of its heat, the loss is correspondingly less. Even certain quantity of oxygen as well, should show about 18-5% then there is no reason why this mode of burning the fuel, i.e. COą. But the best smoke gases of steam boilers show only 12 first with“ primary air" in the producer (C+0=CO), then with or 13%, much more frequently only 10% CO2, and gases from "secondary air" in the furnace (CO+O=CO), should be reverberatory furnaces often show less than 5%. This means preferred to the direct complete burning of the fuel on a grate, that the volume of the smoke gases escaping into the air is unless the above-mentioned advantage is secured, viz. reduction from i} to 2 times in the case of high-temperature operations of the smoke gases to a minimum by confining the supply of air often 4 times) greater than the theoretical minimum; and as as nearly as possible to that required for the formation of CO2, these gases always carry off a considerable quantity of heat, which is only possible by producing an intimate mixture of the the loss of heat is all the greater the less complete is the utilization producer gas with the secondary air. The advantage in question of the oxygen and the higher the temperature of the operation is not very great where the heat of the smoke gases can be very This explains why, in the case of the best-constructed steam- fully utilized, e.g. in well-constructed steam boilers, salt-páns boiler fires provided with heat economizers, where the smoke and the like, and as a matter of fact gas producers have not gases are deprived of most of their heat, the proportion of the found much use in such cases. But a very great advantage is heat value of the fuel actually utilized may rise to 70 or even 75%, attained in high-temperature operations, where the smokç while in some metallurgical operations, in glass-making and gases escape very hot, and where it is on that account allsimilar cases, it may be below 5%.
important to confine their quantity to a minimum. One way of overcoming this difficulty to a certain extent is It is precisely in these cases that another requirement frequently to reduce the solid fuel to a very fine powder, which can be comes in, viz. the production at a given point of a higher temperaintimately mixed with the air so that the consumption of the ture than is easily attained by ordinary fires. Gas-firing lends latter is only very slightly in excess of the theoretical quantity; itself very well to this end, as it is easily combined with a prebut this process, which has been only recently introduced on a liminary heating up of the air, and even of the gas itself, by somewhat extended scale, involves much additional expense and means of " recuperators." The original and best-known form trouble, and cannot as yet be considered a real success. Generally, of these, due to Siemens Brothers, consists of two brick chambers too, it is far less easily applied than gaseous fuel. The latter filled with loosely stacked fire-bricks in such manner that any can be readily and intimately mixed with the exact quantity of gases passed through the chambers must seek their way through air that is required and distributed in any suitable way, and the interstices left between the bricks, by which means a thorough
interchange of temperature takes place. The smoke gases, Water gas in its original state is called " blue gas," because it instead of escaping directly into the atmosphere, are made to burns with a blue, non-luminous flame, which produces a very pass through one of these chambers, giving up part of their high temperature. According to the equation C+H,0=CO+H., heat to the brickwork. After a certain time the draught is this gas consists theoretically of equal volumes of carbon changed by means of valves, the smoke gases are passed through monoxide and hydrogen. We shall presently see why it is another chamber, and the cold air intended to feed the com- impossible to avoid the presence of a little carbon dioxide and bustion is made to pass through the first chamber, where it other gases, but we shall for the moment treat of water gas as takes up heat from the white-hot bricks, and is thus heated up if it were composed according to the above equation. The to a bright red heat until the chamber is cooled down too far, reaction C+H2O=CO+H, is endothermic, that is, its thermal when the draughts are again reversed. Sometimes the producer value is negative. One gram-molecule of carbon produces 97 gas itself is heated up in this manner (especially when it has great calories (1 great calorie or kilogram-calorie=1000 grambeen cooled down by travelling a long distance); in that case calories) when burning to CO2, and this is of course the maximum four recuperator chambers must be provided instead of two, effect obtainable from this source. If the same gram-molecule Another class of recuperators is not founded on the alternating of carbon is used for making water gas, that is, CO+Hs, the system, but acts continuously; the smoke gases travel always heat produced by the combustion of the product is 68.4+ in the same direction in Alues contiguous to other flues or pipes 57.6 = 126 great calories, an apparent surplus of 29 calories, in which the air flows in the opposite direction, an interchange which cannot be got out of nothing. This is made evident by of heat taking place through the walls of the flues or pipes. Here another consideration. In the above reaction C is not burned the surface of contact must be made very large if a good effect to CO2, but to CO, a reaction which produces 28-6 calories per is to be produced. In both cases not merely is a saving effected gram-molecule. But as the oxygen is furnished from water, of all the calories which are abstracted by the cold air from the which must first be decomposed by the expenditure of energy, recuperator, but as less fuel has to be burned to get a given we must introduce this amount, 68.5 calories in the case of effect, the quantity of smoke gas is reduced. For details and liquid water, or 57.6 calories in the case of steam, as a negative other producer gases, see Gas, II. For Fucl and Power. quantity, and the difference, viz. +28.6–57.6 = 29 great calories,
Gas-firing in the manner just described can be brought about represents the amount of heat to be expended from another by very simple means, viz. by lowering the fire-grate of an source in order to bring about the reaction of one gram-molecule ordinary fire-place to at least 4 ft. below the fire-bridge, and by of carbon on one gram-molecule of H,0 in the shape of steam. introducing the air partly below the grate and partly behind This explains why steam directed upon incandescent coal will the fire-place, at or near the point where the greatest heat produce water gas only for a very short time: even a large is required. Usually, however, more elaborate apparatus is mass of coal will quickly be cooled down so much that at first a employed, some of which we shall describe below. Gas-firing gas of different composition is formed and soon the process will has now become universal in some of the most important in cease altogether. We can avoid this result by carrying on the dustries and nearly so in others. The present extension of process in a retort heated from without by an ordinary coal fire, steel-making and other branches of metallurgy is intimately and all the early water gas apparatus was constructed in this connected with this system, as is the modern method of glass-way; but such a method is very uneconomical, and was long ago making, of heating coal gas retorts and so forth.
replaced by a process first patented by J. and T. N. Kirkham The composition of producer gas differs considerably, princi. in 1854, and very much improved by successive inventors. This pally according to the material from which it is made. Analyses process consists in conducting the operation in an upright brick of ordinary producer gas (not such as falls under the heading of shaft, charged with anthracite, coke or other suitable fuel. This
semi-water gas," see sub C) by volume show 22 to 33% co, shaft resembles an ordinary gas producer, but it differs in being 1 to 7% CO2, 0.5 to 2% H2, 0.5 to 3% hydrocarbons, and worked, not in a continuous manner, which, as shown above, 64 to 68% NZ.
would be impossible, but by alternately blowing air and steam B. Waler Gas.—The reaction of steam on highly heated through the coal for periods of a few minutes each. During the carbonaceous matter was first observed by Felice Fontana in first phase, when carbon is burned by atmospheric oxygen, and 1780. This was four years before Henry Cavendish isolated thereby heat is produced, this heat, or rather that part of it hydrogen from water, and thirteen years before William Murdoch which is not carried away by radiation and by the products made illuminating gas by the distillation of coal, so that it was of combustion on leaving the apparatus, is employed in raising no wonder that Fontana's laboratory work was soon forgotten. the temperature of the remaining mass of fuel, and is thus Nor had the use of carburetted water gas, as introduced by available for the second phase, in which the reaction (6) Donovan in 1830 for illuminating purposes, more than a very С+H,0=CO+H2 goes on with the abstraction of a corresponding short life. More important is the fact that during nine years amount of heat from the incandescent fuel, so that the latter the illumination of the town of Narbonne was carried on by rapidly cools down, and the process must be reversed by blowing incandescent platinum wirc, heated by water gas, where also in air and so forth. The formation of exactly cqual volumes. internally heated generators were for the first time regularly of carbon monoxide and hydrogen goes on only at temperatures employed. The Narbonne process was abandoned in 1865, and over 1200° C., that is, for a very few minutes. Even at 1100° C. for some time no real progress was made in this field in Europe. a little CO2 can be proved to exist in the gas, and at 900° its But in America, T.S. C. Lowe, Strong, Tessié du Motay and others proportion becomes too high to allow the process to go on. took up the matter, the first permanent success being obtained About 650° C. the CO has fallen toʻa minimum, and the reaction by the introduction (1873) of Lowe's system at Phoenixville, Pa. is now essentially (c) C+2H2O=CO2+2Hz; soon after the In the United States the abundance of anthracite, as well as of temperature of the mass will have fallen to such a low point petroleum naphtha, adapted for carburetting the gas, secures a that the steam passes through it without any perceptible action. great commercial advantage to this kind of illuminant over coal | The gas produced by reaction (c) contains only iwo-thirds of gas, so that now three-fourths of all American gas-works employ combustible matter, and is on that account less valuable than carburetted water gas. In Europe the progress of this industry proper water gas formed by reaction (b); moreover, it requires was naturally much less rapid, but here also since 1882, when the generation of twice the amount of steam, and its presence is the apparatus of Lowe and Dwight was introduced in the town all the less desirable since it must soon lead to a total cessation of Essen, great improvements have been worked out, principally of the process. In ordinary circumstances it is cvident that the by E. Blass, and by these improvements water gas obtained a more steam is blown in during a unit of time, the sooner reaction firm footing also for certain heating purposes. The American (c) will set in; on the other hand, the more heat has been process for making carburetted water gas, as an auxiliary to accumulated in the producer the longer can the blowing-in of ordinary coal gas, was first introduced by the London Gas Light steam be continued. and Coke Company on a large scale in 1890.
The process of making water gas consequently comprises
two alternating operations, viz. first “ blowing-up" by means waste. A very important improvement in this respect was of a current of air, by which the heat of the mass of fuel is raised effected by C. Dellwik and E. Fleischer. They found that the to about 1200° C.; and, secondly “steaming," by injecting a view that it is unavoidable to burn the carbon to monoxide current of (preferably superheated) steam until the temperature during the blowing-up holds good only for the pressure of blast of the fuel had fallen to about goo° C., and too much carbon formerly applied. This did not much exceed that which is dioxide appears in the product. During the steaming the gas required for overcoming the frictional resistance within the is carried off by a special conduit into a scrubber, where the dust producer. If, however, the pressure is considerably increased, mechanically carried away in the current is washed out, and the and the height of the column of fuel reduced, both of these gas is at the same time .cooled down nearly to the ordinary conditions being strictly regulated in accordance with the result temperature. It is generally stored in a gas-holder, from which desired, it is easy to attain a combustion of the carbon to dioxide, it is conducted away as required. It is never quite free from with only traces of monoxide, in spite of the high temperature. nitrogen, as the producer at the beginning of steaming contains Evidently the excess of oxygen coming into contact with each much of this gas, together with CO or CO2. The proportion of particle of carbon in a given unit of tíme produces other conditions hydrogen may exceed 50%, in consequence of reaction (c) of chemical equilibrium than those existing at lower pressures. At setting in at the close of the steaming. Ordinary." blue” water any rate, experience has shown that by this process, in which the gas, if, as usual, made from coke or anthracite, contains 48-52% full heat-value of carbon is utilized during the blowing-up stage, H, 40-41% CO, 1-5% CO2, 4-5% Na, and traces of hydro- the time of heating-up can be reduced from 10 to if or 2 minutes, carbons, especially methane. If made from bituminous coal, and the steaming can be prolonged from 4 or 5 to 8 or 10 minutes, it contains more of the latter. If " carburetted” (a process with the result that twice the quantity of water gas is obtained, which increases its volume 50% and more) by the vapours from viz. upwards of 2 cub. metres from 1 kilogram of carbon. superheated petroleum naphtha, the proportion of CO ranges The application of water gas as a fuel mainly depends upon about 25%, with about as much methane, and from 10 to 15% the high temperatures which it is possible to attain by its aid, of “illuminants” (heavy hydrocarbons). The latter, of course, and these are principally due to the circumstance that it forms greatly enhance the fuel-value of the gas. Pure water gas would a much smaller flame than coal gas, not to speak of Siemens gas, possess the following fuel-value per cubic metre:
which contains at most 33% of combustible matter against 0.5 cub. met. H, 1291 calories
90% or more in water gas. The latter circumstance also allows CO= 1522
the gas to be conducted and distributed in pipes of moderate 2813
dimensions. Its application, apart from its use as an illuminant
(with which we are not concerned here), was formerly retarded Ordinary "blue" water gas has a fuel-value of at least 2500 by its high cost in comparison with Siemens gas and other calories. Carburetted water gas, which varies very much in sources of heat, but as this state of affairs has been changed by its percentage of hydrocarbons, sometimes reaches nearly the the modern improvements, its use is rapidly extending, especially heat-value of coal gas, but such gas is only in exceptional cases for metallurgical purposes. used for heating purposes.
C. Mixed Gas (Semi-Water Gas),- This class is sometimes We must now turn to the “blowing-up” stage of the process, called Dowson gas, irrespective of its method of production, Until recently it was assumed that during this stage the combus- although it was made and extensively used a long time before tion of carbon cannot be carried on beyond the formation of J. E. Dowson constructed his apparatus for generating such a carbon monoxide, for as the gas-producer must necessarily gas principally for driving gas-engines. By a combination of contain a deep layer of fuel (generally about 6 to 10 ft.), any CO, the processes for generating Siemens gas and water gas, it is formed at first would be reduced to CO; and it was further produced by injecting into a gas-producer at the same time a assumed that hardly any CO, would be formed from the outset, certain quantity of air and a corresponding quantity of steam, as the temperature of the apparatus is too high for this reaction the latter never exceeding the amount which can be decomposed to take place. But as the combustion of C to CO produces only by the heat-absorbing reaction, C+H2O=CO+H,, at the ex. about 30% of the heat produced when C is burned into CO2; pense of the heat generated by the action of the air in the the quantity of fuel consumed for “ blowing-up" is very large, f reaction C+0=CO. Such gas used to be frequently obtained in and in fact considerably exceeds that consumed in “steaming." an accidental way by introducing liquid water or steam into There is, of course, a further loss by radiation and minor sources, an ordinary gas-producer for the purpose of facilitating its and the result is that i kilogram of carbon yields only about working by avoiding an excessive temperature, such as might 1•2 cub. mct. of water gas. Each period of blowing-up generally cause the rapid destruction of the brickwork and the fusion of occupies from 8 to 12 minutes, that of steaming only 4 or 5 the ashes of the fuel into troublesome cakes. It was soon found minutes. This low yield of water gas until quite recently appeared that by proceeding in this way a certain advantage could be to be unavoidable, and the only question seemed to be whether gained in regard to the consumption of fuel, as the heat abstracted and to what extent the gas formed during blowing-up, which by the steam from the brickwork and the fuel itself was usefully is in fact identical with ordinary producer gas (Siemens gas), employed for decomposing water, its energy thus reappearing could be utilized. In America, where the water gas is mostly in the shape of a combustible gas. It is hardly necessary to employed for illuminating purposes, at least part of the blowing- mention explicitly that the total heat obtained by any such up gas is utilized for heating the apparatus in which the naphtha process from a given quantity of carbon (or hydrogen can in is volatilized and the vapours are “fixed” by superheating. no case exceed that which is generated by direct combustion; This process, however, never utilizes anything like the whole some inventors, however, whether inadvertently or intentionally, of the blowing-up gas, por can this be effected by raising and have actually represented this to be possible, in manifest violation superheating the steam necessary for the second operation; of the law of the conservation of energy. indeed, the employment of this gas for raising steam is not very Roughly speaking, this gas may be said to be produced by easy, owing to the irregularities of and constant interruptions the combination of the reactions, described sub A and B, to the in the supply. In some systems the gas made during the blowing- joint reaction: 2C+0+H,0=200+H.. The decomposition up stage is passed through chambers, loosely filled with bricks, of H,0 (applied in the shape of steam) absorbs 57.6 gram calories, like Siemens recuperators, where it is burned by a secondary " the formation of 200 produces 59 gram calories; hence there is air: the heat thus imparted to the brickwork is utilized by passing a small positive excess of 1:4 calories at disposal. This in reality through the recuperator, and thus superheating, the steam would not be sufficient to cover the loss by radiation, &c.; required for the next steaming operation. In many cases, hence rather more free oxygen (ie. atmospheric air) must be principally where no carburetting is practised, the blowing-up employed than is represented by the above equation. All this gas is simply burned at the mouth of the producer, and is thus free oxygen is, of course, accompanied by nearly four times altogether lost; and in no case can it be utilized without great lits volume of nitrogen.'
The mixed gas thus obtained differs very much in composition, I went many changes and much of its early prosperity returned. but is always much richer in hydrogen (of which it contains Hotels and villas were built in the new part of the town that sometimes as much a3 20%) and poorer in carbon monoxide sprang up outside the picturesque walled fortress, and there is (sometimes down to 20%) than Siemens gas; generally it quite a contrast between the part inside the heavy, half-ruined contains more of CO, than the latter. The proportion of nitrogen ramparts, with its narrow, steep streets and curious gable-roofed is always less, about 50%. It is therefore a more concentrated houses, its fine old church and castle and its massive town hall, fuel than Siemens gas, and better adapted to the driving of gas- and the new suburbs and fishermen's quarter facing the estuary engines. It scarcely costs more to make than ordinary Siemens of the Bidassoa. Many industries flourish on the outskirts of gas, except where the steam is generated and superheated in the town, including rope and net manufactures, flour mills, saw special apparatus, as is done in the Dowson producer, which, mills, mining railways, paper mills. on the other hand, yields a correspondingly better gas. As is Fuenterrabia formerly possessed considerable strategic imnatural, its properties are some way between those of Siemens portance, and it has frequently been taken and retaken in gas and of water gas; but they approach more nearly the wars between France and Spain. The rout of Charlemagne in former, both as to costs and as to fuel-value, and also as to the 778, which has been associated with Fontara bia, by Milton temperatures reached in combustion. This is easily understood (Paradise Lost, i: 587), is generally understood to have taken if we consider that gas of just the same description can be place not here but at Roncesvalles (g.v.), which is nearly 40 m. obtained by mixing one volume of real water gas with the four E.S.E. Unsuccessful attempts to seize Fuenterrabia were volumes of Siemens gas made during the blowing-up stage-an made by the French troops in 1476 and again in 1503. In a operation which is certainly too expensive for practical use. subsequent campaign (1521) these were more successful, but the
A modification of this gas is the Mond gas, which is made, fortress was retaken in 1524. The prince of Condé sustained a according to Mond's patent, by means of such an excess of steam severe repulse under its walls in 1638, and it was on this occasion that most of the nitrogen of the coke is converted into ammonia that the town received from Philip IV. the rank of city (muy (Grouven's reaction). Of course much of this steam passes on noble, muy leol, y muy valerosa ciudad, “most noble, most loyal, undecomposed, and the quantity of the gas is greatly increased and most valiant city"), a privilege which involved some by the reaction C+2H2O=CO2+2Hz; hence the fuel-value measure of autonomy. After a severe siege, Fuenterrabia of this gas is less than that of semi-water gas made in other ways. surrendered to the duke of Berwick, and his French troops in Against this loss must be set the gain of ammonia which is 1719; and in 1794 it again fell into the hands of the French, recovered by means of an arrangement of coolers and scrubbers, who so dismantled it that it has never since been reckoned by and, except at very low prices of ammonia, the profit thus made the Spaniards among their fortified places. It was by the ford is probably more than sufficient to cover the extra cost. But opposite Fuenterrabia that the duke of Wellington, on the 8th of as the process requires very large and expensive plant, and its October 1813, successfully forced a passage into France in the profits would vanish in the case of the value of ammonia becoming face of an opposing army commanded by Marshal Soult. Şevere much lower (a result which would very probably follow if it were fighting also took place here during the Carlist War in 1837. somewhat generally introduced), it cannot be expected to sup FUERO, a Spanish term, derived from the Latin forum. The plant the other descriptions of gaseous fuel to more than a Castilian use of the word in the sense of a right, privilege or limited extent.
charter is most probably to be traced to the Roman conventus Semi-water gas is especially adapted for the purpose of driving juridici, otherwise known as jurisdictiones or fora, which in gas-engines on the explosive principle (gas-motors). Ordinary Pliny's time were already numerous in the Iberian peninsula. In producer-gas is too poor for this purpose in respect of heating each of these provincial fora the Roman magistrate, as is well. power; moreover, owing to the prevalence of carbon monoxide, known, was accustomed to pay all possible deference to the it does not light quickly enough. These defects are sufficiently previously established common law of the district; and it was overcome in semi-water gas by the larger proportion of hydrogen the privilege of every free subject to demand that he should be contained in it. For the purpose in question the gas should be judged in accordance with the customs and usages of his proper purified from tar and ashes, and should also be cooled down before forum. This was especially true in the case of the inhabitants of entering the gas-engine. The Dowson apparatus and others those towns which were in possession of the jus italicum. It is are constructed on this principle.
not, indeed, demonstrable, but there are many presumptions, Air Gas.-By forcing air over or through volatile inflammable besides some fragments of direct evidence, which make it more liquids a gaseous mixture can be obtained which burns with a than probable that the old administrative arrangements both of bright flame and which can be used for illumination. Its employ- the provinces and of the towns, but especially of the latter, ment for heating purposes is quite exceptional, e.g. in chemical remained practically undisturbed at the period of the Gothic laboratories, and we abstain, therefore, from describing any of the occupation of Spain. The Theodosian Code and the Breviary numerous appliances, some of them bearing very fanciful names, of Alaric alike seem to imply a continuance of the municipal which have been devised for its manufacture. (G. L.) system which had been established by the Romans; nor does the
FUENTE OVEJUNA (Fuenteovejuna), a town of Spain, in the later Lex Visigothorum, though avowedly designed in some province of Cordova; near the sources of the river Guadiato, points to supersede the Roman law, appear to have contemplated and on the Fuente del Arco-Belmez-Cordova railway. Pop. Many marked interference with the former fora, which were still to (1900) 11,777. Fuente Ovejuna is built on a hill, in a well- a large extent left to be regulated in the administration of justice irrigated district, which, besides producing an abundance of by unwritten, immemorial, local custom. Little is known of the wheat, wine, fruit and honey, also contains argentiferous lead condition of the subject populations of the penifsula during the mines and stone quarries. Cattle-breeding is an important Arab occupation; but we are informed that the Christians were, local indastry, and leather, preserved meat, soap and four sometimes at least, judged according to their own laws in are manufactured. The parish church formerly belonged to separate tribunals presided over by Christian judges;. and the the knights of Calatrava (c. 1163-1486).
mere fact of the preservation of the name alcalde, an official FUENTERRABIA (formerly sometimes written Fontarabia; whose functions corresponded so closely to those of the juder or Lati Pons Rapidus), a town of northern Spain, in the province defensor civitalis, is fitted to suggest that the old municipal fora, of Guipúzcoa; on the San Sebastian-Bayonne railway; near is much impaired, were not even then in all cases wholly destroyed. the Bay of Biscay and on the French frontier. Pop. (1870) At all events when the word forum. begins to appear for the first about 750; (1900) 4345. Fuenterrabia stands on the slope of a time in documents of the roth century in the sense of a liberty or hill on the left bank of the river Bidassoa, and near the point where its estuary begins. Towards the close of the 19th century d. rom. Rechts. See especially i. pp. 154, 259 seq.
"The nature of the evidence may be gathered from Savigny, Gesch. the town became popular as a summer resort for visitors from Compare Lembke u. Schäfer, Geschichte von Spanien, i. 314; ii. 117. the interior of Spain, and, in consequence, its appearance under Or rather forus. See Ducange, s.o.
privilege, it is generally implied that the thing so named is the local fueros of the various districts slowly yielded before the nothing new. The earliest extant written fuero is probably that superior force of imperialism; and only those of Navarre and the which was granted to the province and town of Leon by Alphonso Basque provinces (see Basques) have had sufficient vitality to V. in 1020. It emanated from the king in a general council of the enable them to survive to comparatively modern times. While kingdom of Leon and Castile, and consisted of two separate actually owning the lordship of the Castilian crown since about the parts; in the first 19 chapters were contained a series of statutes middle of the 14th century, these provinces rigidly insisted upon which were to be valid for the kingdom at large, while the rest of compliance with their consuetudinary law, and especially with the document was simply a municipal charter. But in neither that which provided that the señor, before assuming the governportion does it in any sense mark a new legislative departure, ment, should personally appear before the assembly and swear unless in so far as it marks the beginning of the era of written to maintain the ancient constitutions. Each of the provinces charters for towns. The “ fuero general " does not profess to mentioned had distinct sets of fueros, codified at different periods, supersede the consuetudines antiquorum jurium or Chindaswint's and varying considerably as to details; the main features, howcodification of these in the Lex Visigothorum; the “fuero ever, were the same in all. Their rights, after having been remunicipal” is really for the most part but a resuscitation of cognized by successive Spanish sovereigns from Ferdinand the usages formerly established, a recognition and definition of Catholic to Ferdinand VII., were, at the death of the latter in liberties and privileges that had long before been conceded or 1833, set aside by the government of Castaños. The result was a taken for granted. The right of the burgesses to self-government civil war, which terminated in a renewed acknowledgment of the and self-taxation is acknowledged and confirmed, they, on the fueros by Isabel II. (1839). The provisional government of 1868 other hand, being held bound to a constitutional obedience and also promised to respect them, and similar pledges were given subjection to the sovereign, particularly to the payment of by the governments which succeeded. In consequence, however, definite imperial taxes, and the rendering of a certain amount of of the Carlist rising of 1873-1876, the Basque fueros were finally military service (as the ancient municipia had been). Almost extinguished in 1876. The history of the Forces of the Portucontemporaneous with this fuero of Leon was that granted to guese towns, and of the Fors du Béarn, is precisely analogous to Najera (Naxera) by Sancho el Mayor of Navarre (ob. 1035), and that of the fueros of Castile. confirmed, in 1076, by Alphonso VI. Traces of others of perhaps Among the numerous works that more or less expressly deal with even an earlier date are occasionally to be met with. In the fuero this subject, that of Marina (Ensayo historico-critico sobre la antigua of Cardeña, for example, granted by Ferdinand I. in 1039, Castillo) still continues to hold a high place. Reference may also
legislacion 2, principales cuerpos legales de los reynos de Leon y reference is made to a previous forum Burgense (Burgos), which, be made to Colmeiro's Curso de derecho politico segun la historia de however, has not been preserved, if, indeed, it ever had been Leon y de Castilla (Madrid, 1873); to Schäfer's Geschichte von reduced to writing at all. The phraseology of that of Sepulveda Spanien, ii. 418-428, iii. 293 seq.; and to Hallam's Middle Ages, (1076) in like manner points back to an indefinitely remote antiquity. Among the later fueros of the 11th century, the
FUERTEVENTURA, an island in the Atlantic Ocean, forming most important are those of Jaca (1064) and of Logroño (1095). part of the Spanish archipelago of the Canary Islands (9.0.). The former of these, which was distinguished by the unusual Pop. (1900) 11,669; area 665 sq. m. Fuerteventura lies between largeness of its concessions, and by the careful minuteness of its Lanzarote and Grand Canary. It has a length of 52 m., and an details, rapidly extended to many places in the neighbourhood, average width of 12 m. Though less mountainous than the other while the latter charter was given also to Miranda by Alphonso islands, its aspect is barren. There are only two springs of fresh VI., and was further extended in 1181 by Sancho el Sabio of water, and these are confined to one valley. Lava streams and Navarre to Vitoria, thus constituting one of the earliest written other signs of volcanic action abound, but there has been no fora of the “ Provincias Vascongadas.” In the course of the 12th igneous activity since the Spaniards took possession. At each and 13th centuries the number of such documents increased very extremity of the island are high mountains, which send off rapidly; that of Toledo especially, granted to the Mozarabic branches along the coast so as to enclose a large arid plain. population in 1101, but greatly enlarged and extended by The highest peak reaches 2500 ft. In external appearance, Alphonso VII. (1118) and succeeding sovereigns, was used as a climate and productions, Fuerteventura greatly resembles basis for many other Castilian fueros. Latterly the word fuero Lanzarote. An interval of three years without rain has been came to be used in Castile in a wider sense than before, as mean- known. Oliva (pop. 1900, 2464) is the largest town. A smaller ing a general code of laws; thus about the time of Saint Ferdi- place in the centre of the island named Betancuria (586) is the nand the old Lex Visigothorum, then translated for the first administrative capital. Cabras (1000) on the eastern coast is time into the vernacular, was called the Fuero Juzgo, a name the chief port. Dromedaries are bred here. which was soon retranslated into the barbarous Latin of the period
FUGGER, the name of a famous German family of merchants as Forum Judicum;* and among the compilations of Alphonso and bankers. The founder of the family was Johann Fugger, the Learned in like manner were an Espejo de Fueros and also the a weaver at Graben, near Augsburg, whose son, Johann, settled Fuero de las leyes, better known perhaps as the Fuero Real. The in Augsburg probably in 1367. The younger Johann added the famous code known as the Ordenamiento Real de Alcald, or Fuero business of a merchant to that of a weaver, and through his Viejo de Castilla, dates from a still later period. As the power of marriage with Clara Widolph became a citizen of Augsburg! the Spanish crown was gradually concentrated and consolidated, After a successful career he died in 1408, leaving two sons royal pragmaticas began to take the place of constitutional laws; Andreas and Jakob, who greatly extended the business which
i Cap. xx. begins: " Constituimus etiam ut Legionensis civitas, they inherited from their father. Andreas, called the "rich quae depopulată suit a Sarracenis in diebus patris mei Veremundi Fugger," had several sons, among them being Lukas, who was regis, repopulatur per hos foros subscriplos."
very prominent in the municipal politics of Augsburg and who • Mando et concedo et confirmo ut ista civitas cum sua plebe et
was very wealthy until he was ruined by the repudiation by the cum omnibus suis pertinentiis sub tali lege et sub tali foro maneat per saecula cuncta. Amen. Isti sunt fueros quae habuerunt in town of Louvain of a great debt owing to him, and Jakob, who Naxera in diebus Sanctii regis et Gartiani regis,
was granted the right to bear arms in 1452, and who founded the 1" Ego Aldefonsus rex et uxor mea Agnes confirmamus ad Septem- | family of Fugger vom Reh-so called from the first arms of the publica suo foro quod habuit in tempore antiquo de avolo meo et in Fuggers, a roe (Reh)
or on a field azure—which
became extinct tempore comitum Ferrando Gonzalez et comite Garcia Ferdinandez et comite Domno Santio.'
on the death of his great-grandson, Ulrich, in 1583. Johann *This Latin is later even than that of Ferdinand, whose words are: Fugger's son, Jakob, died in 1469, and three of his seven sons, "Statuo et mando quod Liber Judicum, quo ego misi Cordubam, Ulrich (1441-1510), Georg (1453-1506) and Jakob (1459–1525), translatetur in vulgarem et vocetur forum de Corduba ... et quod men of great resource and industry, inherited the family business appellare nisi forum de Corduba et jubeo et mando quod omnis and added enormously to the family
wealth. In 1473 Ulrich morator et populator ... veniet ad judicium et ad forum de obtained from the emperor Frederick III, the right to bear arms Corduba."
for himself and his brothers, and about the same time he began