Ch. IX.] VEINS IN PRIMARY ROCKS. 187 



ations observable in the lode at a in the adit, the 10, 20, 30, 

 and 40 fathoms levels ; and at b in the eastern flucan at the 

 adit : these are branches or parts of the vein separating from 

 the main body. When they are productive of ores (and 

 sometimes they are not inferior in this respect to the un- 

 divided part of the vein), they are denominated lodes, and not 

 branches ; size and the amount of ore being the only circum- 

 stances on which the distinction is founded : and when a lode 

 thus separates into two parts, it is said to take horse. The 

 form and extent of these portions of rock, or horses, depend on 

 the disposition of the branches of the lode : sometimes the 

 branches, like those of a river, reunite again, thus forming an 

 insulated mass of rock; sometimes one branch terminates, 

 and then the horse is connected at its base with the main 

 mass of the rock, or country, having an angular and wedge- 

 shaped form where situated between the branches of the vein ; 

 at other times the base of the horse abuts against a cross vein, 

 as shown in the plan of Huel Jewel mine." 



Such are a few of the appearances which veins exhibit, when 

 they interfere with each other in their course or longitudinal 

 direction, as brought to light by mining operations. We are 

 almost entirely indebted to the same source for details con- 

 cerning throws, or the apparent movements which veins ex- 

 perience by their coining into contact during their descent, 

 in consequence of their dipping towards each other, or in- 

 clining in the same direction at different angles : the results 

 of such an arrangement of veins are very various, and some- 

 times very complicated. 



4. Feins, underlying at various angles, often meet and in- 

 tersect each other. This sometimes happens with lodes, but is 

 more common between lodes and slides, or flucans, which run 

 somewhat parallel with the lodes. 



" In South Huel Towan mine (near St. Agnes, in slate), 

 the lode a a a / bears about E. and W., and has a mean dip 

 of 55 S. ; whilst the vein b b runs 20 S. of W., dipping 

 about 50 N., at b it divides, and reunites at &". 



