ORIGIN AND DEVELOPMENT OF ORE DEPOSITS. 135 



The following are the eleven systems referred to, the 

 directions being given to the nearest whole degree, after calcu- 

 lating the small allowances to be made on account of the 

 convergence of meridians. 



E. & W. Systems. Directions. N. & S. Systems. Directions. 



Finistere 22° S. of W. Vendee 26° W. of N. 



Westmoreland 40° S. of W. Forez 23° W. of N. 



Land's End 8° S. of W. N. of England 8° W. of N. 



Pays Bas 15° S. of W. 



Morbihan 36° N. of W. Longmynd 20° E. of N. 



Ballons 5° N. of W. Ehine 10° E. of N. 



These angles when protracted form 4 natural groups, viz : 

 the E.W. lodes, the N.S. lodes, the N.E. caunters, and the N.W. 

 caunters. Nearly all the East and "West lodes, and all the really 

 good ones in the West of England, are included in the first 

 group ; nearly all the North and South lodes in the second group ; 

 while most of the caunters come very near, if not absolutely within 

 the third and fourth groups. Moissenet remarks that, of the 

 eleven systems, the first four, viz : Finistere, Westmoreland, 

 Land's End, and Pays Bas, correspond with the East and West 

 lodes in all mining districts of the West of England, the 

 Morbihan system is web -developed in St. Just, and both it and 

 Ballons in the Liskeard and St. Austell districts, while the 

 combined effect of these latter is evident in the "caunters" of 

 Camborne and Illogan. 



" The very ancient systems of Vendee and the Forez make 

 a very small angle with each other, and are very nearly 

 perpendicular to the system of Finistere, whilst that of the N. 

 of England is almost exactly perpendicular to the Land's End 



of fracture." It is obvious that the mean bearing of such a lode, which is usually 

 all that a miner records , will not be that of either of the components, but approxi- 

 mately intermediate between the two. Furthermore, it may often happen that a 

 new fracture will take place between two bearings neither of which is exactly in 

 the direction of the strain — both being about equally removed from the said 

 direction. The same remarks apply to the group d. 



*Loc. cit., p. 86. 



