488 EEPOKT ON NATIONAL MUSEUM, 1886. 



G.— SLATES. 



(1) CANADA. 



Slates of excellent quality, sinootli, boraogeneoiis, and strong, and of 

 green, red, purple, and blue-blaek colors, occur in Richmond County, in 

 the province of Quebec. These are now being quarried and are to be 

 found in the principal markets of the United States. The leading 

 quarries as given by Newberry * are those of the New Rockland Slate 

 Company, the Melbourne Slate Company, the Rankin Hill Slate Com- 

 pany, and the Danville School Slate Company.t Of these the writer 

 has seen and examined only material from the New Rockland quarries, 

 a large slab of w^hicli is in the National Museum. It is apparently of 

 excellent quality. 



(2) GREAT BRITAIN. 



The finest roofing slates of Great Britain are stated by Hnll| to be 

 derived from the Cambrian and Lowci' Silurian formations of North 

 Wales. The Cambrian slates are stated to be generally of a green and 

 liurple color, while those of the Silurian formations vary from pale gray 

 to nearly black. The stone splits with wonderful facility into very thin 

 sheets, and the quarries are especially favorably situated both for work- 

 ing and for shipn>ent. Material from these sources has been sent to 

 every quarter of the globe, and has been more extensively used for 

 roofing than any other slate now quarried.§ 



* Report of Judges, p. 164. 



t Further details regarding the slate areas of Canada are given in Geology of Can- 

 ada, 1863, pp. 830, 831. 



tOp.cit, 1^.292. 



§ For a detailed account of the Welsh slates and the methods of quarrying see Davies 

 Slate and Slate Quarrying, Crosby, Lockwood & Co., London. 



