128 Mr. William Phillips on the Veins of Cornwall, 



seldom yield it of a greater price than <£4 or £5 per ton. A few 

 tons were lately sold from the United Mines at £100. The general 

 average perhaps does not exceed about £7. 10s. or £8 per ton. 



In few metalliferous veins does the ore prove so continuous, as 

 after it has been taken away to leave a large hollow load. The in- 

 termediate spaces between the ore are mostly filled with what the 

 miner terms deads, which consist of quartz, fluor, gossan, iron 

 pyrites and other substances, as well as occasionally portions of the 

 country through which the vein runs ; but the walls of the vein are 

 nevertheless generally determinable. The deads are not always a 

 disadvantage to the miner, as they serve to keep apart the coun- 

 try on either side the vein ; but for this purpose, when the vein has 

 been left hollow by taking away a large body of ore, strong timbers 

 are made use of; these are not however always found to be of 

 strength sufficient to prevent the falling in of the cavity. An 

 instance of this occurred in the copper mine called Huel Alfred ; 

 one of the veins of which was hollowed out for about 100 fathoms 

 in depth, 80 fathoms in length at bottom, and 30 fathoms above, 

 and varying in width from 9 to 24 feet. Notwithstanding great 

 labour, skill and expense had been bestowed, and the most substantial 

 timber employed in order to keep apart the walls of the vein, many 

 thousands of tons came down in an instant ; fortunately seventeen 

 men who had been working in the very place on which the whole 

 fell, had left it half an hour before the accident. The whole has 

 been supported, and they are nov^'- working beneath it. 



It has sometimes happened that in a large load, and where it is 

 largest, the miner has suddenly arrived at a piece of dead ground in 

 the middle of it, which in depth spreads wider so as to occupy 

 nearly the whole of the vein, leaving on each side only a small 

 connecting string of ore. This has been known to extend many 



