CANADIAN ROOFING SLATE. 361 



haps also to some extent in that of the old world, is to bo expect- 

 ed mainly from Vermont, it may not be uninteresting here to 

 refer to the slate resources of that state. Three belts of slate rock 

 occur in the state running southward down its eastern, middle and 

 western portions. In the first, which keeps near the boundary of 

 New Hampshire, the slate is of a dark color, and the cleavage gen- 

 erally corresponds with the planes of stratification. Although the 

 belt has a great thickness, but little of it is available for working 

 owing to contortions, the presence of foreign ingredients, imperfect 

 cleavage and cress joints. An occasional band, however, is found 

 to be suitable for roofing slates, and upon one of them the Guil- 

 ford quarries are situated. The slates of this locality are suffici- 

 ently durable, but owing to their thickness, require a heavily 

 timbered roof to support them. They are also liable to become 

 rusty from the presence of oxide of iron. The situation of these 

 quarries is such as to prevent their produce competing successfully 

 with the slates imported from Wales. The slate bands in the eas- 

 tern belt dip at high angles to the horizon, and thus have an ad- 

 vantage for working, over those of the western belt. 



The middle slate belt extends from the Canada line at Lake 

 Memphremagog about half way down . the middle of the state. 

 In places it is found to split into thin sheets, and is of a uniform color 

 — nearly black — differing in these respects from the slate bands of 

 the eastern belt. Northfield, near the centre of the state, is the 

 only place at which it has been worked. Here the price of slate 

 •delivered on the cars is $3.75 a square, or 50 cents more than Mr. 

 Walton's price, on the Grand Trunk cars at Richmond. It may 

 not be generally known that a square of slates is a hundred 

 square feet, and that the greater the number required to make 

 this area, the smaller the price per square. 



The workable seams of the westerly belt are largely quarried for 

 roofing and other purposes in the southwestern part of the state, 

 where slate manufacturing forms a leading branch of industry. 

 The slate is of a more uniform character than that of the eastern 

 or the middle belt, and more exempt from foreign matter, which 

 renders it capable of being sawn, as slab slate, and used for a 

 great variety of purposes. The color of most of the western 

 Vermont slates, like that of the Welsh, is dark purple, sometimes 

 mottled with green spots. Bands of green, and sometimes of red 

 slate are likewise found in this part of the state. Whatever may 

 Can. Nat. ' 24 Vol. VIII. 



