CANADIAN ROOFING SLATE. 367 



reappears further on. East of the river, it is again met with in 

 the strike, with a greatly reduced thickness. It was on this part 

 of the band that the quarry in Cleveland, already mentioned, was 

 opened. 



The whole series in this neighbourhood is tilted to a vertical 

 attitude, and strikes S. 45° to 55° W., or at right angles to the 

 river. The serpentine affords many varieties of green and green- 

 ish-black marble, of which a few have been proved by Sir 

 William Logan, to be of good quality ; and the specimens in the 

 Geological Museum are generally admired. On the west end of 

 the quarry lot, there occurs a bed of chromic iron, of the hard, 

 dark, crystalline variety, worth fifty dollars a ton in the English 

 market, containing, as it does, 53 per cent, of the sesqui-oxide ot 

 chromium.* It appears to be obtainable in su fficient quantities to 

 work at a profit. On the north-east end of the adjoining lot (22 in 

 the 5th range — part of the same property) vitreous copper ore is 

 found along a crack or vein in the serpenti ne ; and further on in 

 the strike, larger deposits of copper ore are found in the township of 

 Orford, associated with the same rock. 



The average price of the Melbourne slates delivered at the 

 railway is $3.25 per square. They are made by contract at the 

 quarry at $1.75, leaving a difference of $1.50 per square. From 

 this is to be deducted 25 cents for cost of carriage to the railway- 

 All other contingencies are covered by 15 cents more, giving 

 upwards of a dollar a square, or 50 per cent, as the net profit to 

 the proprietor. It is to be observed, that this calculation of 

 profit is based on the present working expenses, and makes no 

 allowance for past expenditure or future development. The 

 quarry is now brought into good working order, and, at the 

 present rates the contractors are making large profits. It is calcu- 

 lated that in future, by a different system of working, the proceeds 

 to the proprietor will be not less than 100 per cent, upon the cost 

 after delivering on the cars. 



It is scarcely necessary to notice the superiority of slates, both 

 in regard to appearance and excellence, as a roofing material, over 

 shingles, compositions, and even metals. The original cost of slate 

 is about one-third more than shingles, although cheaper in the 

 end ; it is one-half less than tin and one-third less than galvatiized 

 iron. The reason of slate not being adopted in preference to 

 these latter, is often attributable to prejudice, arising from examples 



*Mr. Robb's analysis. 



