Kingdom.]

Class 1 . -MINING AND MINERAL PRODUCTS.South Side—Areas S. 1 to S. 27.

171

are called “ knocking-stones,” and the second has theeffect of clearing away all earthy matter. These speci-mens, picked from the heap and washing-grate, are readyfor smelting after being reduced with a hammer to thesize of the ore contained in Case No. 9.

Case No. 5 contains ordinary “bouse,” or lead oretaken from the trunking-box after passing through thewashing-grate, being, in fact, a process of washing andsizing , with a view to the further operations exhibited inthe following cases.

Case No. 6 contains specimens of ordinary bouse, whichfrom the size of the pieces and intermixture of rock andore, require to be passed through the rollers of the crush-ing-mill.

Case No. 7. Specimens of the same bouse, or ore,after having passed through the rollers of the crushing-mill.

Case No. 8. So far the processes have consisted simplyof extraction of the ore from its place in the mine,—of thepure samples of ore being picked out and washed andsized, ready for being smelted at once, without furtheroperations,—of the remainder or poorer samples beingwashed and separated by an iron grate or sieve into twosizes, the larger having to be ground between rollers toreduce it to the same size as the smaller, which hadpassed the grate, and when reduced to this stage, thewhole is ready for an operation called “ hotching,” whichconsists in placing the ore in a tub with water—thebottom of this tub is a sieve—and the whole is subjectedto a rapid vibratory vertical movement, or shaking, bywhich a separation of the ore takes place. The water sofar lessens the weight as greatly to facilitate the down-ward movement of the ore, which of course is muchheavier than the spar and other materials connected withit. The vibratory movement is sometimes given bymanual labour: a long arm, moving with a spring, isjerked up and down by a strong lad jumping on a raisedstand, so as to produce the required motion. The sameresults may be obtained by machinery; and a model ofa hotching apparatus accompanies these specimens. Itrepresents the mode in which the hotching tubs areworked in some of Mr. Beaumont’s mines in West Allen-dale ; and both the mode of applying the machinery, andthe manufacture of the model representing it, are due tothe ingenuity of Mr. Joseph Hetherington, one of theengineers or wrights employed at these mines.

The ore prepared as has already been described, andafter being shaken in the “ hotching-tub ,” the upper partis entirely waste or refuse, and is called “cuttings,” ofwhich this case, No. 8 , contains a specimen.

Case No. 9 contains lead ore as obtained from thebottom of the hotching-tub, and is ready for beingsmelted.

Case No. 10 contains what is called “ undressed smid-dum,” being what has passed through the sieve of thehotching-tub into the box or case of water in which thehotching-tub vibrates.

Case No. 11 is the “ smiddum,” after being dressed orcleared from all foreign substances in what is locallycalled a “ buddle,” and the ore, in being so washed, issaid to be “ huddled.”

. Case No. 12 . In all operations where a stream of run-ning water is employed to wash lead ores, it is obviousthat many of the smaller particles will be carried awaywith the stream. These particles are allowed to settleby their specific gravity in what are called slime-pits,being merely reservoirs in which the water passes over atong space with a very tranquil movement. In the Case,.°. an example of the slime or deposit in these

slime-pits, undressed.

C^se No. 13 contains a specimen of what is called

slime ore,” having been extracted or separated from theslime shown in Case No. 12 . This separation is effectedby manual labour in what are called “ nioMng-trunks”and is made ready for a final washing or separation in thedolly-tub.”

Case No. 14 contains slime ore obtained, not by manuallabour, but by means of a patented invention of Mr.Brunton’s, by which the slime, being first freely mixed

with water, is allowed to fall on a revolving canvas clothinclined at a moderate angle, and upon which also dropsof water are constantly falling, so as to keep the surfacewell wetted. The heavier particles of ore being thus freeto move, are carried up the slightly inclined surface ofthe canvas, and so pass round a roller to a cistern below,in which they are deposited, while the lighter particlesof earthy matter and spar are at once carried down thecanvas by the stream of water. The ore thus obtainedrequires finally to be washed in the dolly-tub, after whichit is fit for being smelted.

Case No. 15 contains slime ore as taken from the dolly-tub, which is the last operation connected with the wash-ing and dressing of lead ores, as usually practised in thelead-mines belonging to Mr. Beaumont, and in the lead-mines generally of this part of the kingdom.

The German huddle is also occasionally used in dressingslime ores. A considerable improvement was made inthis apparatus about 30 years ago by Mr. Robert Stagg,of Middleton, in Teesdale.

Case No. 16 exhibits a specimen of “ selected” orsuperior' lead ore, in the form in which it is sent to anddeposited at the smelt-mill, ready to be smelted.

Case No. 17 contains an example of the ordinary orcommon lead ore, as prepared and ready for smelting.

Cases Nos. 18 and 19 contain the same ores (select andcommon) after having undergone the operation of being“ roasted,” or exposed to a suitable temperature in areverbatory furnace, the object being to free it from thesulphur contained in galena, pure specimens of whichconsist of lead 86 - 6 and sulphur 13'3. By this process theore is rendered more easily reducible.

Case No. 20. Grey slags formed in the process of orehearth smelting, and from which the lead is afterwardsobtained at the slag hearth.

Case No. 21. Black slags, being the residuum obtainedfrom the slag hearth, and which assume the granulatedform from being made to flow, when in a melted state,into water.

Cases Nos. 22 and 23 contain examples of the crystalsof selected and common lead, as formed in the process ofseparating or desilvering the ore: patented by Mr. H. L.Pattinson, and first brought into operation at Mr. Beau-mont’s smelt-mills.

Cases Nos. 24, 25, and 26, contain specimens of thefume or deposit in the long flues connected with thesmelt-mills : that in No. 24 being the ordinary fumecollected in the flue, No. 25 the same, after being roastedfor the ore hearth, and No. 26 the same, roasted for theslag hearth. The flues or chimneys are built of stone,8 feet by 6 feet inside, and are upwards of 83 miles long.

Cases Nos. 27, 28, and 29. Litharge in the ordinaryround state, and two varieties of Timsed litharge whichhave been passed through a sieve.

Case No. 30. Skimmings from the surface of meltedlead, showing iridescent hues, which are frequently ofgreat intensity and beauty.

V. Lead and Silver prepared por Sale. —Thefollowing are contained in the large upright case whichcompletes the several objects sent in illustration of lead-mining, viz.:—

No. 31. Lead made from roasted lead ore, and placedin a model-mould, same as No. 37.

No. 32. Grey slag lead, in mould.

No. 33. Selected lead, in mould.

No. 34. Common lead, in mould.

No. 35. Lead made from ore-hearth fume, in mould.

No. 36. Lead made from slag-hearth fume, in mould.

No. 37. Empty mould, marked W. Blackett, whichname, or its initials, viz., W. B., form the well-knownmark of the lead produced from Mr. Beaumont s mines.

No. 38. A pig, or piece of common lead, weighing12 stones, or 14 cwt. .

No. 39. A pig, or piece of selected lead, weighing

12 stones, or 14 cwt. „„ , ,

In the above examples, Nos. 31 to 37 are models ofreduced, size. The dimensions of the ordinal y pieces oflead, as manufactured for sale, are shown in Nos. 38 and39. The number of pieces usually manufactured at these