Kingdom.]
Class 1.—MINING AND MINERAL PRODUCTS.South Side—Areas S. 1 to S. 27.
147
galleries at right angles to each other, leaving largepillars of coal to support the roof. These pillars areafterwards removed, and the roof allowed to sink down,forming what is technically called the goaf.
Owing to the large proportion of gas present in the coal,and the fact that such gas is given off readily from anewly-fractured surface, and on mixture with atmosphericair becomes highly explosive, it is necessary to takegreat care of the ventilation of the mines, and this moreespecially when the roof is partly fallen. The methodof working has therefore reference to this, and the lightsemployed, where any danger is supposed to exist, mustalso be adapted to the peculiar condition of the mine.The models showing the mode of ventilation, and thestructure of the ventilating furnace used to produce astrong current of air to circulate through the mine,together with the safety lamps (invented by the late SirHumphry Davy ), will illustrate these methods. Themechanical contrivances for drawing and screening thecoals (separating the dust and small coal) are also veryimportant in the economy of the district.
There ai*e nearly 200 pits or collieries worked in thedistrict: the number of men and boys employed is about26,000; and the average price of the coal as shipped forLondon is not more than 11s. per ton. The estimatedquantity of coal, soldinthe year 1847, was about 7,730,000tons.—D. T. A.]
274 The Brymbo Company, Wrexham, Wales —
Producer.
Minerals, &c., found at Brymbo, near Wrexham, Den-bighshire, or in the neighbourhood.
Main coal got at the Brymbo colliery.
[The Brymbo colliery is in a part of the Flintshire coal-field illustrated by the specimen of coal exhibited by Mr.Oakeley. There will be found a magnificent squaredblock of this coal in the enclosure beyond the westernextremity of the Building.—D. T. A.]
275 Randall, J., Coalport , Salop —Proprietor.
Minerals and their associated fossils, used in the manu-facture of Shropshire iron. Also, specimens of clays,pottery, brick, tile, &c.
Cement from the curl-stone, manufactured by M.Brosely.
276 Watney, Alfred, Llanelly, Wales —Producer
and Manufacturer.
Specimen of pure anthracite coal, raised from a pit atG-wendraeth, Llanelly , Carmarthenshire.
Two models of anthracite blast furnace (scale half-inchto one foot), situated at Gwendraeth, Llanelly , Carmar-thenshire.
Pig-iron of excellent quality for foundery, tin-plate andboiler-plate purposes.
Furnace cinder or slag, classified according to thequality of iron made simultaneously with each.
Raw coal used in furnace; it burns without smoke, andbears the strongest heat without decrepitation.
Raw and calcined clay ironstone.
Sandstone used for lining hearths and boshes of furnace.
277 Clive, J. W.—Producer.
Raw and calcined specimens of a stratum of mineralsubstance found among the scaly iron ores of Clanwaycolliery, Tunstall, Staffordshire .
Thirty-five samples of ironstone, coal, &c.
300 Huggie, Brothers, Gateshead-on-Tyne —Manufacturers.
Samples of plaited ropes for mining purposes.
400 Butterley Company, Alfreton —Producer.
Specimens of coal and ironstone, and of organic remainsin connexion with the Derbyshire coal-field, includinganalyses of the different coal strata.
Iron in its different stages of manufacture, includingpig-iron, refined metal, puddled, and merchant bar-iron.
[The great central coal-field of England extends intoDerbyshire , and the works at Alfreton and its vicinityhave been long known as exhibiting in all no less than30 seams of coal, whose aggregate thickness is 78 feet.
The iron ore associated with the coal in this district isof excellent quality, and very abundant.—D. T. A.]
401 Baugh-Deeley & Co.—Producers.
Iron chains used in coal mines.
Improved vice.
402 Crutwell, Allies, & Co., Gunn Celyn and BlainaIron Works, Abergavenny —Manufacturers.
Pieces of pig-iron, forge pig-iron, and refined metal; andcinder, or scoria, produced from them.
Puddled, merchant, and beat bar iron, with scoria.
Finished rail, showing fracture.
Specimen of sigillaria, from the lower coal measures,Cwm Celyn and Blaina Iron-works.
Rails connected, showing a new mode of fastening.The mode of riveting the rails to the chairs with lateralpins or rivets is the patent invention of H. D. Bird, Esq.,of Petersburg, Virginia .
403 Cawley, P., Soho, near Birmingham —Inventor.
Complete model and section of a Staffordshire coal-pit,with apparatus for preventing explosions in coal-mines,by exhausting the combustible gases, and supplying pureair in its place, and for enabling the workmen to ascer-tain in what state the air is, in the workings of the mine,before going down.
[The thick coal of Staffordshire is worked in a manneraltogether different from that adopted either in North-umberland or Yorkshire , as there is constant danger ofaccident from the fall of the roof, besides that arisingfrom the presence of gas which necessarily accumulatesin large quantities in the upper recesses of the mine.
The usual mode of getting the coal is by sinking apair of shafts at convenient distances, and extending apair of levels from the shafts. On reaching the intendedlimit of working, the coal is removed on one or bothsides of the levels, for a distance of about 20 yards wide;but pillars of 7 or 8 yards square are left at intervals forthe support of the roof. Between each side lane of thiskind a larger and more effectual barrier is left, 16 or 20yards wide, and this is called a fire-rib, and serves notonly to prevent a crush of the roof, but to allow of adam being afterwards constructed to confine the gases.A large quantity of coal is left below by this process ofmining, amounting sometimes to one-half or even two-thirds of the whole. The ventilation of the thick coalmines is generally imperfect, owing to the large body ofair to be moved; but more accidents occur from falls ofthe roof than from explosions. The workings are gene-rally left in the care of uneducated contractors calledbutty colliers. —D. T. A.]
404 Brunton, W.—Producer.
Model of a plan proposed for ventilating mines, withdiagrams.