INDUSTRIES the stones had been broken to convenient size, they were carried to a stamping-mill, whose mechanism by this time had become so improved that it would work for a couple of hours without attention, 1 one John Tomes, when a boy thirty years before, having patented an invention by means of which, when there was not enough ore in the coffer, the water was turned off, whereas before this a bell had been used which only gave warning when the coffer was empty, by which time the mill was often broken. 2 One wheel cou!4 now work the stamps in three or four coffers. Leaving the stamp heads, the ore was subjected to a series of operations, the object of which was to grade and concentrate it by application of running water. From the stamps it was washed through a grate into a ' launder,' or shallow trench, where it was divided into < forehead,' ' middle,' and ' tails,' according to its specific gravity. After having been ' trambled ' or buddled, it was ' sezed,' ' dilleughed,' crazed or ' framed,' as required. The buddle is described as a long square tye of boards or slate about I foot deep, 6 feet long, and 3 feet broad, wherein stood a man barefooted, who, with a ' trambling shovel,' cast up ore upon the buddle head as high as his middle. 8 The stuff was worked both vqith the shovel and with the feet, and, as the buddle was traversed by a gentle flow of water, the effect of the operation was to separate the ore into several qualities, the heaviest remaining at the head, and the lightest being deposited at the foot.* There also were ' drawing buddies ' for ' retrambling,' which had no tye, but a plain, sloping board. 4 Sezing consisted in the use of a hair sieve, in- stead of the drawing-buddle, to grade the tin. 4 Dilleughing was performed by putting the 'forehead' of the doubly-trambled tin into a canvas sieve, and shaking it in a large tub of water. The tails from the buddle were thrown into strakes, or tyes, of which there were com- monly three or four in succession, where the 'slimes,' or finer ores, were separated from the coarser ' roughs.' 4 The latter were crazed and retrambled, 6 the former were framed, 6 the frame being a rack 6 feet long by 3^ feet broad, sus- pended on two pivots like a cradle. In this account we find mention, for the first time, of the process known as calcining, to burn away the impurities of the ore. It was done in a square kiln, heated by furze, 6 the ore being spread over a flat granite slab, placed above the furnace, over which the flame played. Having been stirred on the slab with a rake, r the ore was finally pushed into the fire, the fire- 1 ' Mineral Observations on the Mines of Cornw. and Devon,' Philosopb. Trans, vi, 2108.
- Ibid. 2108-2109.
3 Ibid. 2109. 4 Ibid. 21 10. 6 Ibid. 2111. 6 Ibid. 7 Ibid. 21 12. place, when choked up, emptied, and the mixture of ore and ashes retrambled. Rude as many of these operations were, they show a great advance in mining skill since the time of Carew. Dr. Merrest, a few years later, describes the tin stuff as dried in a furnace on an iron plate 8 before being crazed, which seems an inexact reference to calcining. He says, also, that stuff not worth working was thrown into heaps which, in six or seven years, would be fit for re- working. The germ of truth in this statement, undoubtedly made in all honesty, seems to be that, just at that date, advances in dressing were unusually rapid, and every few years operations became more precise. Improvements had also been made in smelting. The slovenly habit of burning the blowing- house to catch the tin in the thatch, which Fuller mentions in 1662, had been replaced by the construction of chambers in the chimneys for the deposit of metallic dust. 9 Although smelting with pit coal was still unknown, a difference had been made in the fuels used for various grades of ore. Moor, or stream tin was fused by charked peat ; lode tin by charcoal and peat mixed ; and slag by charcoal alone. 10 Following closely upon this advance in ore- dressing came the invention of improved devices for mine drainage. As the tin districts of Corn- wall became further developed, mining had taken on more of the character of lode-mining. The stream works were still largely in evidence in 1765," but in 1778 Pryce gives us to understand that they were of minor importance. Few changes had taken place in their operations since the days of Carew. The adventurer sank a hatch, three or five fathoms, to the shelf on which the tin stones were deposited. When he had found, by a rough washing on the point of a shovel, that it was ' paying ' tin, he drained his work by a level, and continued working with the aid of a few helpers until the spot was exhausted. 12 In lode mines the accumulation of water called for more advanced methods. At the beginning of the eighteenth century John Coster had taught the Cornish miners to use one large water-wheel, 40 feet in diameter, instead of the half-dozen smaller ones then used for a single mine. 13 His invention, however, was overshadowed by that 8 The Relations of Tin Mines and the Working of Tin in Cornwall,' by Dr. Merrest, Pbiksoph. Trans. xii, 952. 9 Worth, Historical Hotel on the Progress of Mining Skill, 50. 10 ' Mineral Observations on the Mines of Cornw. and Devon,' Philosopb. Trans, vi, 2113. 11 Jars, Voyages Metallurgques, iii, 187. 11 Pryce, Mineralogia Cornubiensis, 132-133. 18 Ibid. 307. 549
