Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/130

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Mr. William Phillips on the Veins of Cornwall.

depth. A satisfactory trial of their nature and value can rarely be made, without sinking 30, 40, or even 60 fathoms below the surface, and driving, at various depths, east and west on the “course of the load.”

Symptoms in Veins.

In the whole range of the employments of man, there is not perhaps another in which experience and ingenuity are more often and completely baffled than in mining. Not unfrequently the appearances in a vein considered to be of the most promising kind, lead on the most experienced miners during the lapse of many years only to ultimate and immense loss; while on the other hand, from the product of veins, which by men of not less experience have been declared to promise no advantage, large profits have been reaped. The great copper mine called North Downs, in the working of which no less a sum than £90,000 was lost, may be considered as an instance of the first, and Huel Alfred, from which a greater sum has been gained, is an instance of the second. There is scarcely one symptom on which the miner most relies that has not occasionally deceived him. It may be curious however to add some of the symptoms in favour of which the miner is greatly prejudiced. There is no one more favorable in his estimation than a gossany load. I remember that of North Towan Mine was of this description, and of so great promise, that several of the most experienced practical miners did not hesitate to declare it superior, in that respect, to any other they had seen; and that, if compelled to venture all they possessed, in the working of any one vein, it should be that of North Towan; but, after much time and expense had been bestowed in trying it, it was found to be very poor, and was therefore abandoned.