On the Aerated Barytes. 60^ 



was then left (landing during a period of fixty years 

 until the year 178 1, fince which it has been 

 regularly worked.* 



As the greateft quantities of the Aerated Barytes 

 lie near the furface, they were probably gained 

 during the very firft period of working the mine, 

 it being ufual here to take the uppermoft part of 

 the vein firft, and clear all before them as they 

 go deeper. But as that foflil, was never fuppofed 

 to be of any ufe, or to polTefs any intrinfic value ; 

 in all probability it has not been removed from 

 the fpot, and great quantities of it muft be con- 

 tained in the old heaps of ftones and rubbifli 

 thrown out of the mine. Much of it may alfo be 

 had from the old works, or what is called the Old 

 Mm, in the interior of the mine, having been 

 placed there with other ftones and wood to prevent 

 the fides from falling in, after the vein had been 

 worked out. Another fource from which it will 

 probably foon be obtained in large quantities is the 



• To give fome idea of the fmall extent of it, it will 

 only be neceffary to mention, that during the firft five years 

 of this latter period they did not raife above four ton of 

 lead per annum, and that in the three laft, they have raifed 

 in all only feventy-three ton, which difference feems to have 

 been occafioned by the driving of the South Level, at the 

 depth of forty-two yards from the top of the New Engine 

 Shaft, for the purpofe of clearing the mine of its water, 

 which before was raifed to the furface with much difficulty 

 by a water wheel. The number of Men employed now is 

 from ten to fix teen. 



Nevy 



