There is one more point of distinction between the two kinds, and that is in the surface indications, which may possibly be due to atmospheric influences. In Italian exploration the prospector is not guided by any hard lines or ridges on the rock surface of the ground, as in Canada. On the contrary, he finds cracks in the perpendicular face of the rock filled with a white powdery substance which, when the surface is broken away, is said to assume a leathery appearance, after which, when further entry is made, the true asbestos is found.
Thus, it will be seen that there is not only a considerable difference between the two sorts of asbestos which supply the demands of the market, but that the mode of winning it is also different; as are, moreover, the natural indications which guide the explorer in his search after the mineral.
FOOTNOTES:
[1] "Encyl. Brit." Art. "Asbestos."
[2] A member of the Geological Survey Department, Ottawa.
[3] See post, p. 66.
CANADIAN MINING FOR ASBESTOS.
And now I will leave the subject of the Italian mines altogether, and proceed to give some account of the asbestos mining industry as carried on in Canada; mainly the result of my notes and observations during a residence at the mines.
The main sources from which the supply of asbestos in the Dominion is derived lie in the province of Quebec, in the counties of Megantic and Beauce. The serpentine rock in which it is found crops up at intervals all along the belt of what has been previously alluded to as the "altered Quebec group"[4] (pre-Cambrian), throughout a range of over 120 miles in length, occasionally attaining a width of more than 2,500 feet, mostly bearing from north-east to south-west, and crossing the Coleraine District nearly east and west. It extends almost uninterruptedly from the boundary of Vermont, in the State of Maine, running north-eastward, to some distance from the Chaudière River, a little beyond the latitude of Quebec.