British Association for the Advancement of Science. 9 



of Mr. Snow Harris, though no doubt whatever was felt as to the 

 answer which it would be proper to give to such an inquiry. The 

 efficacy of the protectors of Franklin in every possible situation, 

 provided they be constructed upon proper principles, and mounted 

 in a suitable manner, is now universally admitted. 



Mining. — Mr. Tarlor, jun., stated, that, in the course of his 

 experience in practical mining, he had observed certain conditions 

 necessary for the profitable working of metals. In the oldest, or 

 scar limestone, he had observed that the miner was not remuner- 

 ated ; . but in newer lead measures he had a better chance of suc- 

 cess, as in grits and shales. The best chance was in altered rocks. 

 In Cardiganshire he had observed a remarkable case in a slaty 

 rock : where very schistose, the workings were poor ; but where 

 the rock was diced, as the workmen call it, they were certain to 

 be rich: the strike of the altered rock being N. and S., and that 

 of the veins E. and W. He had seen remarkable proofs of the 

 mechanical theory in North Carolina, especially in the rich veins 

 of iron ore in that country. Mr. Sedgwick remarked, that fissures 

 caused by crystallization were, in general, very small; and that 

 joints seldom coincided with rents ; — that in districts where gran- 

 ite approaches slate rocks, we may be certain of finding the rich- 

 est metalliferous deposits. 



Catastrophe in a, ikTme.— Mr. Sedgwick requested the attention 

 of the meeting to an account, which he was about to submit, of 

 the late unfortunate accident at the Workington Colleries. He 

 pointed out, on the geological map, the rocks which occur in that 

 neighborhood, and stated some of the phenomena of the stratifi- 

 cation of the coal measures, which are there very much disturbed. 

 There is an anticlinal line, on the opposite sides of which the 

 strata dip differently, so that, in one place, very important beds of 

 coal crop out under the sea. Workings, quite submarine, have ac- 

 cordingly been carried on for some time : in the Isabella pit, a 

 depth of one hundred and thirty-five fathoms under high Avater 

 has been reached. A culpable want of caution has been shown 

 by the managers of late, as they have caused the workings to 

 reach too near the sea — even within fourteen fathoms of it ; and 

 the pillars and roof of the older works had been taken away, by 

 which the danger was greatly increased. There had been re- 

 peated warnings from the shrinking of the ground, and from an 

 old work having become filled with water;— ^Iso in the new 



YoL. XXXIV.— No. 1, 2 



