482 



Scientific Geology. 



that of the vein a, in Ackworth, although I did not then examine the 

 case as carefully as I should now. It occurs two miles north of 

 Chester village in Chester. The granite mass is several rods wide, 

 and the dip of the mica slate on each side of it, about 50 degrees 

 west. 



(12) Granite in Mica slate Chester ; 



In the eighth volume of the American Journal of Science, Dr. Em- 

 mons has described an interesting case of overlying granite in Chester, 

 with veins proceeding from it downwards. The mass is 5 rods in 

 length. 



A portion of the hornblende slate (on No. 1 1 ) is seen running 

 nearly east and west, or at right angles to the usual direction. Be- 

 low the granite mass b, also, the strata are shifted almost 90. 



It is near the apex of this hill, that the interesting minerals above 

 mentioned occur, and on the side of the apex opposite to that represen- 

 ted. The granite here is the coarsest I have ever seen : and proba- 

 bly the largest beryls in the world are found in it. 



No. 13. exhibits the manner in which mica slate is sometimes en- 

 veloped by granite ; the latter rock decidedly predominating. The 

 spot here represented is several rods long, and occurs in Chesterfield, 

 a little north of the meeting house. The dip and direction of the 

 mica slate do not differ much from what is usual in the vicinity. 



(13) Granite and Mica slate ; Chesterfield. 



The following case, No. 14, occurs about half a mile east of the 

 meeting house in Williamsbur^h. A granite vein about 4 feet wide. 



