TUANSACTIONS OF THE SECTIONS. 429 



The depth of the mines has been increased 100 fathoms 

 since the period of the drainage being completed, being at the 

 rate of about 8 fathoms a year. 



There are, in the whole concern, 95 shafts, besides other 

 perpendicular communications from level to level underground 

 called vrinzes. The depths of the vphole added together make up 

 about 22,000 fathoms, or 25 miles ; and the levels, or galleries, 

 will make up, in horizontal distance, a length of 38,000 fathoms, 

 or about 43 miles. 



Wheal Abraham is an old copper mine, the working of which 

 was abandoned a few years since, the vein having ceased to be 

 productive in depth. It was, until very lately, the deepest 

 mine from the surface in Cornwall, but is now surpassed by 

 the Consolidated mines. 



Dolcoath mine was formerly called BuUen Garden, and a 

 section of it as it was at that time will be found in Dr. Pryce's 

 work, Mmeralogia Cornubiefisis^ published in 1778. It wasthen 

 rather more than 90 fathoms deep, and probably one of the 

 deepest mines at that time. It has, therefore, been sunk 140 

 fathoms since ; but, like all the great mines, it has not been in 

 constant work. It has now been actively prosecuted for many 

 years, and at present stands third in the list of copper mines in 

 Cornwall, arranging them according to the value of their pro- 

 duce. That of Dolcoath, however, does not amount to one half 

 of that of the Consolidated mines. 



Ecton mine is celebrated in most books on mineralogy as one 

 of the principal copper mines in England ; and it was so at one 

 period, though the produce is now inconsiderable. It is situ- 

 ated in Staffordshire, on the borders of Derbyshire, and is 

 very curious, from being in limestone and having no regular 

 vein. The ore has been found in large masses, irregularly de- 

 posited, and is generally taken to be an example of contempo- 

 raneous formation. The mine has been regularly worked for a 

 long series of years, and is now nearly exhausted. It is the 

 property of the Duke of Devonshire, and very large profits 

 were given by it in the latter part of the last century, some of 

 which, it is said, were applied by the late Duke to the erection 

 of the beautiful Crescent at Buxton, The mine is not far di- 

 stant from this place, and is in a very picturesque situation on 

 the banks of the river Manifold. 



Mr. Taylor gave some account of the extent to which steam 

 power is at present employed in Cornwall in draining the mines 

 which penetrate so far beneath the level of the sea, showing 

 the influence that the great improvements, which have from time 



