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Mining is the general term applied to the exploring, working, extracting, and preparing th< 

 distributed, and in greater or less relative abundance. Gold is frequently met with, but only 

 of profit. Iron is widely dispersed, and its ores occur abundantly either in regular beds or asi 

 occur in large quantities; arsenic bismuth, nickel, cobalt, &c., although somewhat abundant, i 

 do not occur in the same uniform manner in the various strata. Thus, coal, salt, gypsum, an 

 of copper and lead present occasionally a bedded appearance; but the greatest number of min 

 more or less at right angles to the strata. These veins may be described as fissures or crevic 

 consolidation of the rock, and then subsequently filled with various mineral substances. The 

 with a metallic ore, but is occupied with crystalline (sometimes not) minerals with which the 

 extracting. Veins generally dip or incline from a right angle, (see diagram) and sometim 

 1,500 feet from the surface. 



The most abundant and extensive iron ores are those of .the nodules of clay ironstone associa 

 found in the carboniferous limestone of some counties. Galena, or lead ore, although found ir 

 Northumberland, &c. where 

 it occurs in veins of differ- 

 ent kinds, and frequently 

 contains much silver, vary- 

 ing from two to eight 

 ounces to the ton. Gold 

 has been found in Cornwall, 

 North Wales, and in Wick- 

 low in Ireland. Tin is 

 chiefly associated with the 

 granitic and metamorphic 

 rocks of Cornwall, but is 

 also obtained by washing 

 the sands and gravel of the 

 same county, a process 

 called ' streaming', and like 

 that employed for obtaining 

 gold in auriferous districts. 



The chief supply of cop- 

 per in England is from the 

 ores which occur in the 

 metamorphic schists, &c. of 

 Cornwall and Devon. In 

 Cornwall, the rich copper 

 lodes run east and west, 

 and when they meet with 

 tin lodes pass through and 

 sometimes heave or shift 

 them. 



The chief objects in 

 mining are facility in ex- 

 tracting the ore, drainage, 

 and ventilation. The ac- 

 companying illustration is 

 a representation of a copper 

 mine; the shafts, of which 

 three are shown, form the 

 principal entrance to and 

 exit from the .mine, and 

 through which the ore is 

 brought to the surface by 

 means of machinery moved 

 by horse or steam power, 

 and also by which the water 

 is raised to the adit or 

 drainage level. The adit 

 is driven from the lowest 

 ground through the lodes 

 to the perpendicular shaft, 



LONDON: PUBLISHED 



