134 Mr. William Phillips on the Veins of Cornwall.^ 



west or metalliferous veins* in the direction nearly of north and 

 south, are technically termed Cross Courses. They rarely produce 

 copper or tin, or any other metallic substance. They vary from 

 half an inch to a few feet in width : the underlie of some is east, of 

 others west ; others again have little or no perceptible underlie, but are 

 nearly perpendicular to the horizon. In some tracts of the mining 

 country they are of very frequent occurrence, as the accompanying 

 ground plan of Herland mine will evince. 



Cross Courses, or north and south veins, may be subdivided into 

 1st. a Quartzose vein, to which the general term of Cross Course 

 has been given — 2nd. a vein containing a soft marly or clayey sub- 

 stance of a bluish or whitish appearance, called a Flucan ; and 3d, a 

 vein containing a substance of an ochreous and friable nature and of a 

 yellow colour, called by the miner a Cross Gossan. Every cross course 

 or cross gossan is however accompanied by a flucan. In speaking 

 of these veins the miner sometimes gives them their technical appel- 

 lations, but he is more habitually disposed, whatever the substances of 

 these veins may be, to call them by the familiar term of cross courses. 



The principal advantage derived from the north and south veins is 

 that, when their substance is flucan, or even when a continuous vein 

 of flucan, however thin, accompanies the quartz or gossan, they pre- 

 vent the water of the neighbouring country from troubling a mine, 

 and they are sometimes left to perform that useful office, as was the 

 case between Huel Sparnon and East Huel Sparnon, near Redruth, 

 But their disadvantages are numerous ; for although the regular me- 

 talliferous veins are occasionally found to be but little or not at all dis- 

 turbed by the passing of the substance of the cross vein through 

 them, except by the mere division of the load, it more often happens 



* A rare exception (the only one I am acquainted with) has been found in the mine 

 called Huel Alfred j a description of some of its veins is annexed. 



