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Mine, where no large vein of pure ore has yet been discovered ; 

 the Mount Hope Blue Mine, Mount Hope Mine, Teabo Mine, 

 Mount Pleasant Mine, Harvey's Mine, Sterling Mine, and Bur- 

 well Mine. These several mines are here designated in the 

 order in which they occur, passing from northeast to southwest. 

 It is not intended to convey the impression that the above classi- 

 fication into three belts of veins is regarded as positively accu- 

 rate, for the distances between the excavations, especially along 

 the two first ranges, are so very considerable, as to suggest a rea- 

 sonable doubt whether we might not refer them to a greater 

 number of parallel belts. 



Describing the mines in the order above given, we find the most 

 northeastern of the southeastern range, to be the excavation called 

 Muir's Mine. This is about a mile and a half to the northwest 

 of Rockaway. The vein at the surface of the ground, where it 

 is occasionally exposed, is six inches thick, widening as it de- 

 scends, and becoming two and a half feet thick at the depth of 

 thirty feet. The adjoining rock is a compact gneiss, dipping 

 parallel with the vein, which inclines at an angle of 45° or 50° 

 to the southeast. 



At a considerable distance to the southwest of the above is 

 Sweed's Mine, situated about midway between Rockaway and 

 Dover. Here the general features are the same, the dip being 

 50° to the southeast. 



The thickness of the vein of solid ore varies from five to twelve 

 feet. Next to the hanging or overlying wall, there is usually a 

 band, of about three feet in thickness, of excellent compact ore ; 

 -beneath this succeeds four feet of spar, consisting largely of 

 vitreous felspar, and under this again occurs a very poor ore, 

 mingled largely with the extraneous mineral matter of the foot- 

 wall or floor, from which the vein is not clearly separable. The 

 separation between the vein and the hanging wall, on the con- 

 trary, is well defined. The upper division of the vein is soft and 

 of a granular structure, and yields a good iron. The impurer 

 portion next the foot-wall affords, on the contrary, an iron cha- 

 racterized as red shart. It is worthy of remark, that the adven- 

 titious matter in the red short ore, is not diflferent from that in the 

 ore of standard goodness. The ore in the vein is thrown into 

 some irregularity by wedges or horses of a species of rock, 



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