324 GEOLOGY OF THE SECOND DISTRICT. 



Prof. Hitchcock, tlicy are unconimonly numerous upon the White mountains, so much so as to 

 conceal the rock, and cause great difEcuhy in getting siglit of it : but this is by no means the 

 case on any of the mountains of New-York ; tliey are numerous, it is true, yet much loss so 

 tlian in New-Hampshire. Tlie cause of this difference I attribute to the existence of natural 

 joints, into which water percolates and freezes, and this results in the breaking up of the 

 strata. The rocks of the Adirondack weather with great rapidity upon their summits ; and 

 though natural joints exist, and the rocks are broken in the same manner as upon the White 

 hills, yet they are wanting in those divisional planes which mark the separation of strata, and 

 hence the eflect of frost is more limited upon the former than upon the latter. 



The general color of the hypersthene rock is grey, light and dark intermixed, and the exte- 

 rior is always lighter than the interior. The feldspar is ordinarily checked with fine scams, 

 and somctinies the surface is powdery from disintegration. The rapid disintegration is confined 

 to the liigher part of the mountains ; and the boulders, which are found scattered about the 

 fields at their base, have little disposition to crumble. 



The agricultural character of the soil formed by this rock differs in no respect from the 

 granitic soils of other districts. It is, however, favorable to the growth of most kinds of 

 vegetables, particularly the graminaj or grasses. The evidence of this statement is very 

 strong ; for wherever clearings are made, and timothy or herdsgrass seed happens to be scat- 

 tered, it springs up and produces an extraordinary growth. This may be witnessed particu- 

 larly by the road sides, or where cattle have been fed upon hay : in fact, the stalk is fre- 

 quently too thick for fodder. 



Uses to loliich the hjpersthcne rock viay he applied. 



Some of the varieties of this rock might be emj^loyed for ornamental purposes, provided it 

 can be cut without too much expense. It is well known that all the materials which enter 

 into its composition receive a strong polish, and many of the masses contain crystals of labra- 

 dorite which opalesce. The smoke-grey seems to be best adapted to ornamental purposes, 

 as the combination of colors are more agreeable to the eye. The strongly opalescent crystals 

 of labradorite cannot be said to be abundant, though there is no lack of the substance, for it 

 may be seen in almost every mass upon the surface ; still, good specimens, or those which 

 are large and free from intermixture, are by no means common, or rather are rarely to be 

 obtained at the present time. When this region is cleared, and the surface rocks more 

 exposed, it will undoubtedly be found more abundant. It is a great desideratum to discover 

 some method by which granite and hypersthene rock might be cut or sawed into slabs, similar 

 to those of marble. This material might then be brought into extensive use for tables, mantel 

 pieces, and other ornamental and useful purposes, from which it is now excluded. No mate- 

 rial now in use could compare with it in beauty. 



