LEAD 51 



wrought about 1720, it produced 100 oz. of silver in the ton of lead. Huel Pool, 

 near Helstone, about 1790, yielded from 40 to 50 oz. of silver per ton of lead, and 

 works were erected for extracting tho silver. The lead ore of Wheal Rose contained 

 60 oz. of silver per ton. 



In Devonshire, the Combe Martin and Beer Alston mines have long been cele- 

 brated for their argentiferous lead ores. It is stated that the produce of these mines 

 was unusually great in the reigns of Edward I. and Edward II. In 1293, "William 

 do Wymundham accounted at the Treasury for 270 Ibs. of silver raised in Devon. 

 In 129-1, it amounted to 5211. 10s. weight; and in 1294, to 704i!. 3s. Id. weight. In 

 1296, great profit is stated to have been derived from the Devon mines ; and 360 

 miners were impressed out of Derbyshire and Wales to work in them. In 1360, a writ 

 was issued, authorising certain persons to take up as many miners and workmen as 

 should be necessary to work in the king's mines in Devon, allowing them reasonable 

 wages according to the custom of the country ; to arrest and imprison such as should 

 resist, till they should give security to serve the king in the said mines, and to buy 

 and provide timber at a competent price. 



Henry, bishop of Winchester and cardinal of England, as one of the executors of 

 John, duke of Bedford, who had a grant from the king of the gold and silver mines 

 of Devon and Cornwall, rendered 26 Ibs. and 2 oz. weight of pure silver as the 15th 

 part of the pure silver raised in those counties from 15th December, 21st, to 16th 

 August, 23rd of the same king's reign. 



The Combe Martin mine was re-opened in the reign of Elizabeth. The working 

 of this mine was strongly recommended to the Long Parliament in 1659 ; but 

 Lysons observes that it does not appear to have been again worked until the close of 

 that century, and then without success. In 1813 it was again opened and worked 

 for four years, producing only 208 tons of ore in that time. In 1837 they were again 

 worked, and it was evident that the previous mining operations had been very un- 

 skilfully managed. The two lodes near Beer Alston have produced large quantities of 

 argentiferous galena, often containing from 80 to 120 oz. of silver per ton of lead. 

 According to Mr. Hitchings, tho greatest quantity which occurred in that part of them 

 named the South Hooe mine was 140 oz. of silver per ton of lead. In 1784 and 1785 

 tho silver produce of these mines amounted to 6,500 oz. From Huel Betsy, near 

 Tavistock, which was re-opened in 1806, from 300 to 400 tons of lead, and from 

 4,000 to 5,000 oz. of silver, were annually obtained. Lead mines were worked at a 

 very early period in the Isle of Man, but the recent workings only date from the 

 commencement of the present century. The mines of Cardiganshire were evidently 

 worked by the Romans. In the reigns of Henry VII. and of Elizabeth they attracted 

 much attention, and German miners were invited to work them. 



The English lead-miners distinguish three different kinds of deposits of lead ore : 

 rake-veins, pipe-veins, and flat-veins. The English word ' vein ' corresponds to tho 

 French term filon ; but miners make use of it indifferently in England and France, to 

 indicate all the deposits of this ore, adding an epithet to distinguish the different forms ; 

 thus, rake-veins are true veins in the geological acceptation of the word vein ; pipe- 

 veins are masses usually very narrow, and of oblong shape, most frequently parallel to 

 the plane of the rocky strata ; and flat-veins are small beds of ores interposed in the 

 middle of these strata. 



In the north of England, which, on account of its great preponderance in produce, 

 we take as the basis of our description of lead mining, the ores are for the most part 

 found in veins (lodes in Cornish) and flats. Although different names have been as- 

 signed to occasional varieties, the usual occurrence of lead ore is in rake-veins, or 

 direct running veins, usually named as veins, with some distinctive appellation pre- 

 fixed, as, for example, Kampgill Vein, Hudgillburn Vein. Other veins, lying parallel, 

 receive a similar prefix, with the addition of the words north, east, or south ; but for 

 the last-named the word sun is often used ; as, for instance, Hudgillburn Sxm Vein, 

 and 2nd and 3rd Sun Vein if further discoveries are made of other parallel veins. 

 Considerable quantities of ore are also raised from horizontal extensions of portions 

 of the vein called flats, and these are interposed between the strata adjacent to the 

 vein. 



Hake-veins are the most common form in which lead ore occurs in Cumberland. 

 They are in general narrower in the sandstone which covers the limestone than in the 

 calcareous beds. A thickness of less than a foot in the former becomes suddenly 3 or 

 4 feet in the latter ; in the rich vein of Hudgillburn, the thickness is 17 feet in the 

 Great limestone, while it does not exceed 3 feet in the overlying Watersill or sandstone. 

 This influence exercised on the veins by the nature of the enclosing rock, is instruc- 

 tive ; it determines at the same time almost uniformly their richness in lead ore, an 

 observation similar to what has been made in other countries, especially in the veins 

 of Kongsberg in Norway. The Cumberland veins are constantly richer, the more 



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