Page:Popular Science Monthly Volume 36.djvu/544

528 of the mines are along the line of the Quebec Central Railway, which runs from the city of Quebec to Sherbrooke, the capital of the so-called Eastern Townships of Canada, and cluster around two points a short distance apart and about midway between the two cities. In this district the serpentine forms a very rugged country, rising into bold peaks and ridges, the ruggedness and boldness being enhanced by numerous faults and dislocations of the rock. Bush-fires have recently passed over much of it, and the partially burned trees, with the scarred and seamed rocks as a back-ground, constitute a somewhat drear and dismal scene.

In the serpentine the asbestus forms irregular veins, varying from mere threads to four, six, and occasionally even more inches in width. The fiber is always at right angles to the sides of the vein, unless thrown otherwise as a result of faults. In some cases the mineral has been found concentrated in pockets, from which several tons have been taken. The color of the asbestus in the veins is white, greenish, or yellow, but near the surface the veins are frequently more or less discolored from infiltration through the shattered rock of water carrying oxide of iron. At a depth, and where solid rock is reached, this trouble usually ceases. The asbestus veins are frequently traversed by bands of foreign matter, such as compact serpentine, chromic and magnetic iron, and these, of course, lessen the value of the veins in which, they occur, since they cut up the fiber and must be removed at considerable trouble.

Associated with the asbestus one usually finds a considerable quantity of coarsely fibrous mineral, for which, as yet, no use has been found, together with foliated and slaty forms of serpentine. Some of the latter are of very singular appearance. To use the words of an English gentleman who spent some time in the Canadian asbestus region, "Many of these fragments, as they lie on the ground after blasting, have so much the appearance of a wood-cutter's choppings that, if placed side by side with actual choppings from rough timber, exposed to the weather, the one could in no way be distinguished from the other except, of course, by handling." Others, again, in color and shape very much resemble strips of fancy confectionery.

Still another singular associate of the asbestus is a mineral of a white or green or yellow color, occurring in thin veins. When first exposed it is so soft that it may be easily indented by the finger-nail, but on contact with the air it soon hardens and assumes an appearance somewhat like porcelain. Analysis shows it to be closely related to serpentine.

Mining is carried on by cutting down the hills of asbestus-bearing serpentine, much as a farmer cuts down a stack of hay or straw, or by open quarrying on the level. The rock is blasted