INDUSTRIES 



to the dressers' interest either to be lazy, or 

 to be hurried and slipshod in their work, the 

 favourite way was to set the ore to dress in 

 proportion to the price it brought at the 

 smelter's. 1 



In the stannaries the tributer paid the land- 

 lord, bounder, and adventurers their respective 

 dues in piles of tin-stone ready for the stamps, 

 and retained the residue. In the copper mines 

 the tributer excavated, raised, and prepared the 

 ore for smelting at his own expense. It was 

 then given over to the adventurers, who disposed 

 of it at the ticketing, and from the cash pro- 

 ceeds paid the workmen according to the rate 

 previously agreed. 2 Another anomaly is ex- 

 emplified by the system of private sampling 

 described by Pryce. 



' The takers of tribute pitches in copper are 

 also obliged to mix their ores with those of 

 other pitches, or with the owners' ores, and to 

 sample them according to the will and discretion 

 of the captains, otherwise the parcels of ore 

 would be small, where there may be twenty 

 pitches on tribute in one mine. Before the 

 parcels are mixed together, they take from each 

 a fair sample. The assay master, who buys at 

 the public ticketing or sale a mixed parcel of 

 ore, has these private samples given him, which 

 he assays for zs. 6d. each, with all the judgment 

 and dexterity he is capable of, to make the most 

 of each, and it is a very rare thing for any com- 

 plaint to arise, so expert are they in their 

 business.' 3 



' The use of private samples is this. Although 

 the sundry parcels of ore mixed for sale may 

 appear nearly of one value at sight, yet it must 

 necessarily follow that some difference will arise 

 from the different management in the dressing 

 and other incidental causes. In a mixed parcel 

 of 50 tons A may have 20 of 15 per ton, B 

 25 of 14 los., and C 5 of 16 per ton, 

 according to private samples, yet the gross 

 50 tons may sell for 1 5 5/. per ton. Never- 

 theless the amount must be divided among the 

 tributers according to the selling price, subj-ct 

 to regulation by private samples ; in other words, 

 the excess or diminution for what it sells must 

 be proportioned by the produce of the private 

 samples, for if 50 tons sell at 15 5*., the 

 amount is equal to 762 los. Pursuant to the 

 above private samples, A's 20 tons at 15 bring 

 300 ; B's 25 tons at 14. los. bring 362 

 los. ; C's 5 tons at 16 bring j8o, a total of 

 j/42 lot., or 20 short, by private sample. 

 This is called a 20 increase.' 3 The method of 

 proportioning this among the tributers, says 

 Pryce, is by the rule of three. 4 ' It is evident,' 

 he continues, ' that if the adventurers were to 

 account to the tributers at the private prices, 

 they would deprive them of 20, of which they 

 ought to have their respective proportions, it 

 being the absolute value for which the copper 

 was sold. It is clear also that by mixing these 



1 Pryce, Minerahgia Cornubiensis, 240. 



'Ibid. 188. 'Ibid. 190. ' Ibid. 191. 



three parcels they have altogether brought a 

 better price by 20 than if they had been sold 

 separately.' 5 



As in the tin mines, the element of luck in 

 taking pitches, resulting sometimes in leaving 

 the workman half starved, the fact of the system 

 being open to innumerable opportunities for 

 crooked dealing on the part of the miners, and 

 the consequences of the practice of auctioning 

 the tut and tribute pitches to the lowest bidder, 

 resulting too often in a fierce competition for 

 work, which reduces the price paid the miner to 

 a merely nominal sum, 6 are combining gradually 

 to make tribute working a phenomenon of the past. 

 Improvements in copper dressing in the century 

 and a quarter since Pryce wrote, may be summed 

 up in the statement that the various processes 

 which the latter so thoroughly described have 

 been simplified by the application of machinery. 

 The first great improvement effected upon this 

 basis was the substitution of crushing machines 

 for bucking. The first crusher is said to have 

 been erected at Dolcoath by Trevithick in 

 1 804.' Others were used in the Tavistock 

 district about 1 8 1 4, 8 and in the course of a few 

 years were introduced into all large concerns, 9 

 under the name of halvan crushers. In every 

 operation common to both, copper dressing has 

 since advanced with that of tin. A distinctive 

 feature in the nineteenth century has been the 

 attention paid to the sizing of the stuff, effected 

 by revolving riddles and sizing wheels, which 

 greatly facilitates subsequent treatment. 9 



A further economy was effected by the process 

 known as precipitation. Costar, early in the 

 eighteenth century, had observed at Chacewater, 9 

 that copper held in solution in mine water might 

 be precipitated by means of iron. Precipitation 

 was tried at Wheal Crofty, and although aban- 

 doned there, was introduced at Cronebane, 

 Wicklow, under the superintendence of a Cornish 

 mine captain. 10 From Ireland it went to Cuba, 

 and in 1854 from Cuba to Cornwall again, 

 where it was applied to the waters of the 

 Gwennap adit. Its practice at present has 

 become uniform throughout the county. 



The various vicissitudes which the copper 

 mines have suffered since their establishment on 

 a sound basis by the smelting arrangements made 

 with the Swansea companies, have been due not 

 so much to the exhaustion of their lodes as to 

 underselling by newer and richer mining fields. 

 The first conflict was with the enormously rich 



5 Pryce, Minerahgia Cornubiensis, 191. 

 * English, Mining Almanack, i, 1 20- 1 29. 

 ' Worth, Historical Sketch of the Origin and Progress 

 of Mining Skill in Devon and Cornvi. 44. 



8 De la Beche, Geology of Cornwall, Devon, and West 

 Somerset, 594. 



9 ' Copper Mining in Cornwall,' by Jos. Carne. 

 Trans. Roy. Geol. Soc. ofConttv. iii, 63. 



10 Worth, Historical Notes on the Origin and Progress 

 of Mining Skill in Devon and Comw. 44. 



569 



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