252 GEOLOGY OF THE SECOND DISTRICT. 



of the Sanford ore, and probabl)' the qualities of the iron will be much the same as those 

 already enumerated. 



Another outcrop, apparently of the same ore, occurs on the opposite side of the lake, in the 

 direction of Hill's island. It disappears under the water of the lake, and hence its actual 

 extent cannot be ascertained ; that there is a large amount of ore at this locality, there can be 

 no doubt, and sufficient in itself to justify the erection of extensive works. It is not easily 

 determined whether this is really a prolongation of the Sanford vein ; it appears a few rod> 

 too far to the west to be in the line of its strike, unless the Sanford vein passes beneath the 

 lake, which is not improbable, as the western limit has not been ascertained. The distance 

 of the Sanford vein from the site of the present works, is two miles and fifty-three rods ; and 

 the w^hole surface of the ground is such, that a railway may be constructed which shall have 

 any amount of descent that may be desired. 



From these data, then, we may estimate the whole length of the Sanford vein as about two 

 and a half miles. Intermediate between the several large outcrops, ore appears at the surface 

 in sufficient abundance to indicate the presence of the vein beneath. We have, therefore, 

 in addition to the evidence furnished by external characters, that of ore scattered on the sur- 

 face, on the line of the strike of the main vein ; an indication which rarely if ever has failed, 

 when tested by the only sure method, that of excavation. On this subject, I may with pro- 

 priety remark further by referring to the experience of miners in the vicinity of the Peru iron- 

 works, who have frequently traced a vein of ore, simply by the presence of a few grains in 

 the loose stones on the surface, a distance of a mile at least, and have verified their opinion 

 as regards the presence of ore beneath by excavation. The same fact has also repeatedly 

 fallen under my own observation. 



Of the. Veiti called the Coarse-grained Black Ore. 



This vein is situated in close proximity to the site of the present works ; in fact, the foun- 

 dations of several of the buildings rest on this vein. It takes its name from the color and 

 coarse granular texture of the ore. Its texture throughout is coarser than the Sanford ore, 

 and it is harder or more tenacious ; still it is not the hard ore of miners, or one that works 

 hard, and produces hard and brittle iron. 



As to the purity of the black coarse-grained ore, the same remarks might be repeated which 

 were made on that of the ore of the Sanford vein. The impurities are intermixtures of the 

 earthy minerals, as hypersthene, labradoritc, and small masses of dark colored serpentine. 

 In one or two instances, masses of sujphuret of iron, of the size of a butternut, have been 

 seen. That no injurious substance exists in the ore, is fully shown by the quality of the iron 

 produced from it. This is evidence of the best kind, and supersedes the necessity of making 

 any further remarks on this point. 



With our present knowledge, it is impossible to assign definite boundaries to this vein. On 

 a line measured east and west, commencing at the supposed eastern limit of the vein, and 

 terminating at excavations near the western limit of the cleared fields on the west, it gives a 



