Kingdom.]
Class 1.-MIKING AND MINERAL PRODUCTS.South Side—Areas S. 1 to S. 27.
163
blocks of tin, known as lews’ tin, have not (infrequentlybeen found in the mining localities.
Till a comparatively recent date, tin was the onlymetal which was sought for; and, in many cases, the mineswere abandoned when the miners came to the “ yellows,”that is, the yellow sulphuret of copper. The greatestquantity of tin has been produced by “ streaming” (aswashing the debris in the valleys is termed); and thisvariety, called “ stream tin,” produces the highest pricein the market.
The conditions under which these deposits occur, arecurious and instructive. At the Carnon Tin StreamWorks, north of Falmouth, the rounded pebbles of tinare found at a depth of about 50 feet from the surface,beneath the bottom of an estuary, where trees are dis-covered in their place of growth, together with humanskulls, and the remains of deer, amidst the vegetable accu-mulations which immediately cover the stanniferous beds.According to Mr.' Henwood’s measurement, the sectionpresents first about 50 feet of silt and gravel; then a bedof 18 inches in thickness of wood, leaves, nuts, &c.,resting on the tin ground, composed of the debris ofquartz, slate, and granite, and the tin ore. At the Pen-tuan Works, near St. Austell , similar deposits occur,proving a material alteration in the level during the periodexpended in the formation of this deposit. Tin is alsoworked out of the lode in many parts, the ore occurringboth in the slate and the granite formations. The modesof “ dressing” the tin ore, preparing it for the smelter,and the processes of smelting, are illustrated in theExhibition.
There has been a remarkable uniformity in the quantityof tin produced in Cornwall during a long period, as willbe seen from the following table: —
Years.
1750
1760
1770
1780
1790
1800
1810
1820
1830
1840
Tons.
1,600
1,800
2,000
1,800
2,000
1.5001,4001,700
3.5005,000
Price per Cwt.£• s.
3 03 155 07 03 53 03 15
The produce of this metal within the last few years hasbeen as follows:—
Years.
Tons.
1844
7,507
1845
7,739
1846
8,945
1847
10,072
1848
10,176
1849
10,719
The copper mines, now so important, were so littleworked until a recent period, that, in 1799, we are toldid a Report on the Cornish Mines, “ it was not until the. e S ln ]dng of the last century that copper was discoveredln Britain .” This is not correct, for in 1250, a copper minewas worked near Keswick, in Cumberland. Edward III .gi anted an indenture to John Ballanter and Waltero bolter, for working all “ mines of gold, silver, andcopper:” but that the quantity found was very small isproved from the fact, that Acts of Parliament were passed>n the reigns of Henry VIII. and Edward VI. , to preventthe exportation of brass and copper, “ lest there shouldnot be metal enough left in the kingdom fit for making
guns and other engines of war, and for householdutensils:” and in 1665, the calamine works are encou-raged by the Government, as “the continuing these worksin England will occasion plenty of rough copper to bebrought in.”
At the end of the seventeenth century, some “ gentlemenfrom Bristol made it their business to inspect the Cornishmines, and bought the copper for two pounds ten shillingsper ton, and scarce ever more than four pounds a ton.”
In 1700, one Mr. John Costar introduced a hydraulicengine into Cornwall , by which he succeeded in drainingthe mines, and “ he taught the people of Cornwall also abetter way of assaying and dressing the ore.”
The value and importance of the copper mines sincethat period has been regularly increasing. During aterm of about 30 years, 220 mines have sold their ores atthe public sales. The following table, from a report bySir Charles Lemon, Bart., M.P., represents the progressof copper mining, from 1771 to 1837 :—
Years.
Tons
of Copper.
Standard Valueper Ton.
1771
27,896
3,347
£.
189,609
£.
81
1780
24,433
2,932
171.231
83
1799
51,273
4,223
469,664
121
1800
55.981
5,187
550,925
133
1802
53,937
5,228
445,094
111
1805
78,452
6,234
864,410
170
1808
67,867
6,795
495,303
770,028
100
1809
76,245
6,821
143
1812
71,547
6,720
549,665
111
1814
74,322
6,369
627,501
130
1816
77,334
6,697
447,959
98
1818
86,174
6,849
686,005
135
1821
98,426
8,514
605,968
103
1825
107,454
126,710
8,226
726,353
124
1827
10,311
745,178
817,740
106
1831
146,502
12,218
100
1837
140,753
10,823
908,613
119
Years.
Ore
Copper
Money Value.
in Tons.
in Tons.
£.
s.
1845
162,557
12,883
919,934
6
1846
150,431
11,851
796,182
6
1847
155,985
12,754
889,287
0
1848
147,701
12,422
720,090
0
1849
146,326
11,683
763,614
0
1850
155,025
12,254
840,410
0
With the improvements in the construction of thesteam-engine, the facilities for working the mines havebeen increased. The first steam-engine employed in thecounty was set to work at Huel Vor Tin Mine, near Hel-stone, in 1713, by Newcomen : but it was not until thereconstruction of the engine was effected by Watt, thatsteam power was generally employed for draining themines. The rapid advance made by Cornish engineers inthe perfection of their engines will be seen by the follow-ing return of the duty, that is, the performance of each,which is reckoned by the number of millions of poundslifted a foot high by the consumption of a bushel of
coals:—
Name of Mine.
Stray Park, 1813 . •
Doleoath, 1816 .Consolidated Mines, 1822Consolidated Mines, 1827Fowey Consols, 1834 .United Mines, 1842
Highest Duty.29,000,00040,000,00044,000,00067,000,00097,000,000108,000,000