Adjoining the Johnson Company's mine is one belonging to the "Boston Asbestos Packing Company," of which Mr. Hyde Rust, of Boston, is treasurer, and Mr. T. Sheridan, local resident manager. This mine is being steadily and efficiently worked, and being practically on the same level with that of the Johnson Company, the produce is of a very similar character. It is remarkably good, and some exceptionally fine asbestos has been got out here. In a pamphlet published a short time ago by the Canadian Government on the mineral resources of Canada, it is stated that the yield from this mine (including of course that last mentioned), is pronounced by European manufacturers to be the finest and strongest fibre of the kind known; and it is further stated that there is no question at all as to the profitable nature of asbestos mining in this belt of country.
The output of the Boston Company's mine, according to the authority just cited, is about 400 tons per annum. Mr. Ells, of the Geological Survey Department, Ottawa, says that in 1886 the quantity extracted was about 700 tons, and the total produce of the mine to the end of that year about 3,000 tons. There must, I imagine, be some misapprehension of the figures here, and I feel sure that those given above are nearer the mark.
The value of the output of this mine is certainly as high, it is possible taking it all round, that it may be higher than that of the last mentioned. Steps are now being taken to introduce machinery and prosecute the work on a more extensive scale.
The next mine here is one of a more recent date, worked by the Brothers Ward, and owned by them conjointly with the Hon. James Ross of Quebec. It is turning out fairly good material, and judging by the indications, coupled with what has been already done, there is no reason to suppose that this mine will not presently be as remunerative as those already mentioned.
The output of this, on the same authority, is 150 tons, which is, I believe, the extreme limit of what has yet been done. This mine has been opened now about four years, and in that time has produced, as near as I could learn when last there, about 400 tons. It is said to be worth from $70 to $80, but I did not hear of any of it fetching more than $70, which is doubtless its present value.
The same gentlemen own some very promising-looking land on the other side of the railway, which, in fact, bisects their property; but as this is on a lower level it looks very much as if they will be troubled with water when they begin to open.
The only other mine now opened at Thetford is that owned and worked by Messrs. King Brothers. It is in the same vicinity and bears much the same character as those already mentioned. The output is given at 175 tons per annum.
These four mines form the Thetford group, and are at present by far the most important in the province. They are on a lower level and are consequently worked at a greater depth than those next to be described. The output for this reason moreover is of a more uniform character, and does not require such close classification as some of the other mines farther on. Practically, No. 1 and No. 3 are the only divisions here, the produce being mostly available for No. 1. No. 3 is a very inferior kind, merely the refuse in fact, which is sold and shipped in bulk at $10 a ton, without being bagged up at all, and is mostly used for cement, boiler covering, &c.
The Thetford river marks the western limit of the serpentine on these properties, the rocks on the other side of the water being mostly altered slates and sandstones. To the east of the railway, which cuts directly across the area, the serpentine forms a knoll with an elevation of about 90 or 100 feet above the line of rails; all the workings at present being confined to this portion of the area. They consist of open cuttings on the face of the hill, apparently very little having as yet been done to ascertain the value of the ground between the railway and the river. There are certainly good indications there, and when I was last at Thetford I found Mr. Ward prospecting in this part with some success. Here, however, is the place where the water trouble will first arise, which will have to be provided for at the outset.
The essential peculiarity of the veins at Thetford is that they are occasionally associated, as already mentioned, with grains and threads of chromic iron and also of magnetite. The magnetite forms rather conspicuous masses between the veins of asbestos in Messrs. King's mine, where it sometimes entirely replaces the latter.[8]