1260
Bauche saddle, leather saddle-bow.
Short-ride saddle, saddle-bow, wooden band.
Child’s saddle; a full-qnilted velvet.
A bit upon a new principle.
1 1 Briqueler and Co., Tenez —Lessees.
Samples of copper pyrites from the Oued Allelahmines.
12 Cabanillas, Widow, Saw-mill Works , Algiers .Live specimens of veneering, adapted for cabinet-work.
13 Cailliez, A. L. J., Mustapha —Cabinet-maker.
A toilet-table, and inlaid work-table, made of nativewood.
14 Canton, —, President of the Chamber ofCommerce, Algiers —Merchant.
Samples of Boucada and Medeah raw wool.
Three samples of Upper Chilif wool combed by ma-chinery.
15 Casteiran, —, Colonist of the St. LouisAgricultural Colony (Oran).
Boiled yellow silk and white silk handkerchiefs, made ofsilks grown by the exhibitor in 1850.
16 Chapel, —, Kouba.
Farina from the canna-root ( Canna discolor)^ a newarticle of food.
17 Chttppart, — , JBirmandreis —Agriculturist.Hard and soft wheats, crop 1850.
Cotton, called Louisiane, crop 1850.
Silk in cocoons, and spun silk.
18 Commission op the Mouzaie Mines.
Crystallized grey copper ores. The Company is aboutto send over to England 2,000 tons of this ore, which areintended for smelting, and will probably be followed bymore.
Sample of copper after the first smelting, produced fromthe ores of Mouzala, and sulphate of copper and sulphateof iron, the product of the same ores, in the factory ofCaronte, near Marseille .
[In the case of English ores of other metals, it is the com-mon practice, in order to save the expense of carriage, tosmelt them close to the spot where they are raised. Copperores, however, are generally raised in places where fuel isscarce. Swansea possesses abundance of coal, and a com-modious and safe harbour; so that the ores of the nu-merous mines of Cornwall, Devonshire, Wales, Ireland ,and the Isle of Man , can be sent at a very easy rate toSwansea to be smelted; and the vessels which convey theore return ballasted with Welsh coal, for feeding thenumerous steam-engines of the mining districts. Duringthe last twenty years, Swansea has also been suppliedwith copper ore from the shores of Europe, from Cuba ,Mexico, Columbia, Peru, Chili, Australia, and NewZealand , and, in the present instance, a new source isopened.
Some of these foreign ores, consisting chiefly of the car-bonate and red oxide, are very rich in copper; but by farthe most abundant is copper pyrites, consisting chiefly ofthe sulphuret of copper, combined with the sulphuret of iron.No less than ten distinct processes are concerned in the re-duction of the poorer ores. They are calcined in reverber-atory furnaces, by which a considerable portion of the sul-phuret of iron is converted into an oxide, while the sulphuretof copper remains unchanged. The calcined ore is strongly
heated with siliceous sand, which unites with the oxide ofiron, and forms a vitreous scoria, or slag; which, beingskimmed off, leaves the heavier copper compound behind.By repeating these processes, the iron, and other metallicimpurities, are got rid of in the slag; the sulphuret ofcopper is then decomposed by heat, and converted into anoxide; and lastly, the oxide is reduced, with the assistanceof carbonaceous matter and a very high temperature.
The management of the fuel in the reverberatoryfurnaces is interesting. These are of large size, beingupwards of 20 feet long, and are so contrived that the(lame of the fuel shall be reflected down upon the soleof the furnace, over which the ore is spread in a layerof a few inches in thickness. But as the anthracite,or Welsh stone coal, produces scarcely any flame, somecontrivance was necessary, to apply to the useful pur-poses of the copper smelter the immense stores of thismineral fuel with which South Wales is supplied. Whenanthracite is raised - to a very high temperature, it formsa vitreous scoria, or clinker , which, in the ordinaryform of furnace, occasions great loss and embarrassment,by choking up the bars of the grate, and, combining withthe iron of the bars, leads to their rapid destruction. Inthe Welsh furnaces, these clinkers are made to performthe office of the bottom bars of an ordinary furnace, sup-porting the fuel, and limiting the supply of air. Theclinkers themselves are supported on iron bars, placed atconsiderable distances apart; these do not perform theusual office of grate-bars, but serve merely as supports forthe clinkers which are piled upon them, so as to forma layer from 12 to 16 inches thick. Above this support,the fuel is in full combustion, and forms the hottest partof the fire; and here it is that fresh clinkers are beingcontinually formed, and in the act of formation they cakewith the numerous fragments of small coal heaped upabove them. As this new clinker forms, it graduallydescends towards the bottom of the fire, and, becomingchilled by the rapid current of ascending air which sup-ports the combustion, splits and cracks into numerousfragments. In this way, new channels are formed, suffi-ciently large to admit the ascending air in powerful jets,which urge on the combustion, but not large enough toallow the small coal to fall out and escape. The calcinerman, who has charge of the operation of calcining the ore,disengages a few of the bottom clinkers as they accumu-late, so as to preserve certain relative proportions betweenthe different parts of the fuel, which have been found byexperience to be best adapted to the successful working ofthe fire.
The anthracite is mixed with about one-fourth of itsweight of small bituminous coal, which, caking therewith,and swelling up by the heat, preserves in the mass therequisite degree of porosity. The layer of anthraciteabove the supporting clinkers is about 12 inches thick.The air traverses this layer through a multitude of chan-nels, formed by the cracks in the clinkers, and the heatedproducts of the combustion stream through the furnace.Under ordinary circumstances, the carbon of fuel undercombustion is converted into carbonic acid, which is anuninflammable gas, and prevents the combustion of otherbodies. By the above arrangement, however, the carbonicacid which is formed by the combustion of the fuel isdeprived of a proportion of its oxygen, and is convertedinto the inflammable gas, carbonic oxide, before, or just asit escapes from the fire into the vault of the furnace. ‘ Butits inflammable property would not, under ordinary cir-