107 



Blendes of Cumberland and Westmorland in the form of the 

 particular species Greenockite, has been questioned by competent 

 authorities. 



Galena, Blue Ore, or Lead Sulphide, is the mineral species 

 ranking next in economic importance to the Coal and the 

 Haematite raised in Cumberland and Westmorland. The greater 

 part of the lead employed in the arts is derived from this 

 ore ; and the mines of Cumberland and Westmorland contribute 

 very largely to the total quantity raised in the United Kingdom. 

 In the year ended with the close of 1880— an exceptionally bad 

 time for lead-mines and miners generally, no less than 3781 tons 

 of lead ore, having a money value of ^38,658 7^. 10^., were 

 raised in Cumberland and Westmorland; and in former years, 

 when trade was good, and mining enterprise in the ascendant, the 

 tonnage raised per annum was considerably in excess of this. As 

 It would be unfair to select any individual mine for special mention, 

 it is better to refer to Mr. Robert Hunt's « Mineral Statistics," 

 compiled at the Mining Record Office for further information on 

 this head. 



Galena usually occurs in connection with some of the vertical 

 lines of dislocation, or faults, that traverse all our older rocks ; 

 where it is found irregularly disseminated through the fault-breccia, 

 or ramifying thence into the contiguous strata, in interrupted strips, 

 nests, bunches, strings, or pockets, each generally consisting of aggre- 

 gations of galena crystals associated more or less with other minerals 

 of less importance in a commercial aspect. The greatest extension 

 of the mineral deposit is nearly always in the direction of the 

 length of the vein, while its extension downward may not exceed a 

 few hundred feet, and its width may vary from a few feet down to 

 a mere fraction of an inch. Only too often it is found to terminate 

 abruptly, even within a short distance of an extensive deposit. 

 Not unfrequently, especially where the vein traverses limestone, or 

 other rocks that yield readily to chemical erosion, the ore extends 

 into the chambers and cavities formed by the partial removal of 

 the rock adjoming the vein, and these cavities are often lined, or 

 even entirely filled, by masses of crystals of galena. 



