SCIENTIFIC SUKVEY. 3gj 



north-easterly direction from the bluff, to the westerly shore of 

 Meduxnekeag lake in New Limerick. On this route it is found 

 occasionally cropping out, and exhibiting the same characteristics 

 as is shown in the bluff near Island Falls. Although, as before 

 remarked, this variety is not so easily wrought as the more strati- 

 fied, or gneissoid varieties, it will nevertheless become, in time, 

 valuable to the surrounding country, affording an inexhaustible 

 supply of this durable material which you are aware is not so gen- 

 erally distributed in this part of the State as it is in the western 

 and middle counties. 



I may remark here that I had an opportunity at Mr. Scwall's to 

 examine specimens of the roofing slate which occurs above this 

 on the banks of the Mattawamkeag in No. 4, Range 4. This slate, 

 which yon mention in last year's Report, (page 319,) is of excellent 

 quality, inexhaustible in quantity, and can be obtained in enor- 

 mously large sheets with the greatest ease. While at the falls I 

 was very kindly entertained by Mr. D. Scwall, an early settler at 

 this place, to whom and to his intelligent family I would here ex- 

 press my obligations for assistance rendered. His son and Mr. 

 Porter of Lowell, who was on his way to No. 4, accompanied me 

 to the bluff and essentially aided me in the examination. 



Siliceous Slate. 



Having completed our preparations, we took our course for the 

 Seboois country, taking the upper road, so called, through No. 5. 

 The slate formation, as you pass northerly and westerly from 

 Patten, maybe seen occasionally cropping out, exhibiting its usual 

 characteristics, until you come into No. 5, Range 6. In this town- 

 ship, on the farm of a Mr. Smith, and about a mile north of the 

 road, is a remarkable formation of siliceous slate, which crops out 

 on the margin of a small stream, forming a bank some twenty or 

 thirty feet in height, and extending westerly over several acres. 



The strike, or direction of the strata of this formation, is north- 

 easterly, the dip nearly perpendicular. The strata, or layers of 

 this variety of slate, vary in thickness from an inch to two or three 

 feet, exhibiting, in their cleavage, a clean smooth surface. There 

 are also joints, or cross seams at different points or distances, 

 thereby forming slabs of different thicknesses, and from a foot to 

 ten or fifteen feet in length. The faces of these joints, or cross 

 seams, exhibit angles of about 120 and 60°, to its opposite plane— 

 46 



