162
Class 1.—MINING AND MINERAL PRODUCTS.South Side—Areas S. 1 to S. 27.
[United
437a Jack, Charles, 8 and 9 Tottenham Court, NewRoad , and 80 Upper Thames Street —Importerand Manufacturer.
Specimens of perforated zinc, of various patterns;mouldings, sash bars, blinds, and other articles of generalutility; manufactured from the zinc imported by “LaVieille Montagne Zinc Company of Belgium/’
438 Glover, T., Clerkenwell — Inventor andManufacturer.
Meters; and the large gas-meter for measuring the gassupplied to the Exhibition Building.
439 Berger, Frederick, 12 Cornhill —Producer.
Specimens Of native red and grey copper ores, from
Trenance mines, Cornwall . These deposits were takenfrom the lode now working in the serpentine formation,being part of a slab of copper of 30 feet in length; pro-duce 96 per cent. The grey ore produces 78 per cent.
[The general condition of copper in the serpentinerocks is curious. Fissures running through these rocksare filled in with heterogeneous matters, an occasionalslab of native copper being found in the crack. It hasnot hitherto been usual to discover more than a fewisolated patches of copper ore; and Trenance mine, onthe junction of the serpentine with the hornblendic slate,is a remarkable exception, producing native copper, thegrey sulphuret of copper, and the red oxide of copper.—R. H.] __
440 Bolitho, Edward, Penzance — Producer.
Model of a reverberatory tin smelting furnace and cir-cular table, 51 inches in diameter. The table revolveson rollers. The model stands in the centre of the table,and is surrounded by specimens of various ores preparedfor smelting, as well as products from the smelting works.
[Near this is placed a model of the dressing-floors,in one of the mines of the Duchy of Cornwall, in whichwill be found illustrations of the mode of washing, &c.The tin ores containing arsenic and sulphur are submittedto a roasting process to expel these, and such as containwolfram are treated by some chemical method, such asthat devised by Mr. Oxland, and elsewhere described.The tin ores are then submitted to the smelting process,as shown in this model, a portion of carbon being em-ployed to prevent the oxidation of the metal.—K. H.]
441 Loxgmaid, William, London —Manufacturer.
Rock salt, chloride of sodium, from Cheshire. Ore ,cupreous pyrites, containing sulphur, copper, silver, oxideot‘ tin, iron, silica, &c., from Cornwall . Salt and ore, mixedand grouud. Sulphate ash, the calcined product of theformer, containing sulphate of soda, chlorides of silverand copper in a soluble state, and oxides of tin and iron,silica, and other insoluble matters. Bleaching powder,hypochlorite of lime, the chlorine of which is obtained bypassing a current of dried air through a close furnace(heated externally) in which the ore and salt are in processof calcination. Silver and copper precipitate, and theirproduce. Glauber’s salts, crystallized sulphate of soda.Salt cake, anhydrous sulphate of soda. Black ash, con-taining caustic and carbonated soda, sulphide of calcium,and coal. Crude alkali, the-lixiviated product of crocus.Purified alkali, or carbonate of soda, obtained from theformer. Crystallized carbonate of soda. Bicarbonateof soda. Insoluble portion of sulphate ash. Crocus,oxide of iron, separated from the former by elutriation—iron the produce. Tin ore, binoxide of tin, obtainedfrom the residual matters of the insoluble portion of sul-phate ash, by further elutriation, as practised at the minesof Cornwall and Devon, in heating tin ores—tin the pro-duce. Roman, or blue vitriol, sulphate of copper, obtainedfrom copper precipitate, by oxidizing the precipitate andtreating it with sulphuric acid. Carburetted oxide of
iron. Black ash waste. Black and brown iron paint.Limestone , carbonate of lime.
[The following is a simple explanation of the essentialdetails of this process :—
Copper pyrites (the double sulphuret of copper and iron )is combined with salt ( chloride of sodium), and roasted ata certain moderate temperature. By this, a double de-composition is effected. Sulphate of soda is produced bythe combination of the sulphur of the ore with oxygen,to form, first, sulphuric acid, which then unites withthe soda of the chloride of sodium. The copper is alsoconverted into a soluble sulphate, the iron being left in astate of peroxidation, and the chlorine liberated, which isemployed in the manufacture of bleaching powder.—R. H.] _
441a Richards, Alfred, Redruth , Cornwall — Designer.
Sectional model of East Pool Mine copper lode, Corn-wall ; showing its direction by an east and west linemarked at the base of the model, and the underlies by aperpendicular shaft. The excavations show where thelode has been developed, and whether it has been workedprofitably; the levels, winzes, pitches, &c., are labelled.
This method of modelling is considered to have anadvantage over sections drawn on paper, as it shows thedirection and underlies of the lodes.
442 Breadalbane, Marquis of, Taymouth, Abcrfeldy ,
Perth —Producer.
Specimens from the copper mine of Tomnadashin, onthe south side of Loch Tay, Perthshire.
443 Redruth Local Committee, Redruth —
Collectors and Producers.
Specimens of copper ore from various mines in Corn-wall : illustrations of the various processes it undergoesin preparation for the market, together with the methodsfor determining the percentage of pure copper. Speci-mens of the stratum in which the ore is found.
No.
Mine.
Parish.
Stratum.
1
Yellow ore.
Alfred Consols
Gwinear
Slate.
2
Yellow with fluor spar
Wheal Buller
Redruth
Granite.
3
Tywamhayle .
Illogan .
Slate.
4
| l
Granite.
5
> Yellow Ore . . . . <
East Crofty .
Illogan .
Slate.
6
Treviskey . .
Gwennap
1 & Slate.
1
8
Yellow, grey, and black
South FrancesCarn Brea . .
Illogan
Illogan
9
Grey ore.
Treviskey . .
Gwennap
Granite.
10
Grey ore .......
South Bassett
Illogan .
11
Black and grey ....
South Frances
Illogan
12
Black in Gosan . . .
Wheal Butler
Redruth
13
Black in Gosan ....
South Frances
Illogan
[The county of Cornwall is the most important mineraldistrict of the United Kingdom , for the number of itsmetalliferous minerals, many of which are not found inany other part of our islands. At a very early period ofour history, mines were worked around the sea-coasts ofCornwall , of which the evidences are still to be seen atTol-pedden-Penwith, near the Land’s End; in Gwennap,near Truro ; and at Cadgwith, near the Lizard Point.The traditionary statements that the Phoenicians tradedfor tin with the Britons in Cornwall , are very fairly sup-ported by corroborative facts ; and it is not improbablethat the Ictes, or Iktis, of the ancients was St. Michael’sMount, near Penzance .
In tlie reign of King John , the mines of the westernportion of England appear to have been principally in thehands of the Jews . The modes of working must havebeen very crude, and their metallurgical processes exceed-ingly rough. From time to time the remains of furnaces,called Jews ' houses, have been discovered, and small