112 Geology of Deerfield, &fc. 



from different elevations. The boundaries of the several 

 formations have not been so carefully noticed near the angles 

 of the map as in the central parts. Of their correctness gene- 

 rally, however, I am confident. The latitude and longitude 

 of Deerfield, from which those on the map were marked, 

 were obtained by taking a mean of the observations given by 

 Gen. E. Hoyt, in the Transactions of the American Academy 

 of Arts and Sciences, and of twelve lunar observations since 

 made. The result is, Lat. 42° 32' 32". Long. 72° 39' from 

 Greenwich. 



With the map is given a view of the strata of rocks from 

 Hoosack mountain to eleven miles east of Connecticut river, 

 on a line nearly east and west, passing through Deerfield. 

 The horizontal distances are laid down from a scale : the ele- 

 vations are assumed. The principal rocks only are coloured ; 

 for it is very difiicult to determine the breadth of many, since 

 they frequently alternate with one another. I have not ex- 

 amined the country on the east side of Connecticut river with 

 sufficient care to be able to extend the section on" that side 

 more than a few miles. 



It may not be amiss to mention, that Mount Holyoke, so 

 much celebrated for the delightful view from its top, has been 

 found, with a sextant, to be 830 feet above Connecticut river. 

 Its height has been frequently overrated. 



The mineralogy of this eection of the country has been but 

 imperfectly explored. I shall mention those minerals only of 

 which I have obtained specimens, and whose localities have 

 not been noticed by mineralogists, 



(Quartz — several varieties. 



1. RockCrystal — abundant. Some good specimens are found 

 in Conway, on feldspar, with the usual hexagonal, pris- 

 matic crystals, and these crystals cross each other in 

 all directions. 



f . Irised Quartz — found in Leyden. 



3. Granular Quartz — in Deerfield. 



4. Radiated Quartz^n Whately and Shelburne. 



5. Blue Quartz — ^in rolled masses on the banks of Deerfield 



river. 



