368 BELL ON THE VALUE OP 



where slates had been unskilfully employed. In our towns and cities 

 they are now displacing these materials, and since good wood for 

 shingles is becoming scarce in the agricultural districts, we may 

 look foward to the time when slates will form the principal roofing 

 material used in Canada. 



But outside of our own country, the market for slates is unlim- 

 ited. For instance, after being sold at Richmond, at the large 

 profits just mentioned, they can be delivered in Portland for $4.14 

 per square and sold in Boston and New-York at from $8 to $10. 

 The western cities in the United States could be more easily sup- 

 plied from the slate quarries of Eastern Canada thin from any 

 others and the prices in the old world are such, that our slate 

 could probably be sent there and sold to advantage. 



Among the desirable qualities of a good slate, are uniformity of 

 color, smoothness of surface, durability and strength with lightness; 

 all of which are possessed in an eminent degree by those of the 

 Walton Quarry, the slates from it being equal to any in the world, 

 They are of a bluish-black color, contain no carbonate of lime, 

 are unaffected by acids and almost perfectly non-absorbent, and 

 thus can, in no way, be affected by the weather. . The rock is fine 

 grained and splits with great facility when newly taken from the 

 quarry, but the slates harden rapidly and acquire great toughness 

 and strength. From analyses by Dr. T. S. Hunt, the Melbourne 

 slates are shown to have a very striking resemblance in composition 

 to those from Bangor in Wales, and also to those from Angers in 

 France. Slates from the latter place have been exposed for a 

 hundred years, without perceptible deterioration, on the roof of 

 the seminary building at the corner of Notre Dame and St. 

 Francois Xavier Streets in Montreal, which proves that a slate 

 covering is well adapted to resist the influence of the Canadian 

 climate.* It is to be regretted that no analysis of the Vermont 

 slates is available for comparison, but the purple varieties are more 

 liable than our bluish black slates, to fade and give the roof a 

 checkered and unsightly appearance, and hence the latter are the 

 more desirable, especially where artistic arrangement is required. 

 While the bands or " veins" of workable slate in the principal 

 Vermont quarries are said to be only about 18 to 24 feet thick, 

 the Melbourne band has been ascertained to have a thickness of 

 at least 1*700 feet, opposite the Walton Quarry, and to occupy a 



* Descriptive Catalogue of the Economical Minerals of Canada sent to 

 the International Exhibition of 1862. 



