BY EDGAR HALL, F.C.S., AND HENRY G. STOKES, F.G.S. 117 



sixth is of first grade quality. As a rule the harder and darker 

 coloured serpentines are the most productive, the soft rock being 

 seldom workable ; and hill sides barely covered with soil are the 

 sites where the best quality occurs. Until recently all the work 

 at the mines was done by hand, and the cost per ton of mineral 

 averaged £5, but lately machinery has been introduced which 

 both cheapens the work and enables smaller veins to be worked 

 at a profit. The market price of asbestos at the present time is 

 from £15 to £60 per ton, so that the margin of profit is large. 

 Only the very best quality brings the higher price, and in some 

 mines the bulk of the mineral is fit only for inferior purposes 

 and is sold for from £5 to £8 per ton. The supply seems to be 

 less than the demand, as the present quotations are much above 

 those ruling up to 1888, which were for 1st, £20 to £25 ; 2nd, 

 £10 to £15 ; 3rd, £5 to £8 per ton of 20001bs. 



As mined, chrysotile is as heavy as the rock in which it ig 

 enclosed — the fibres being tightly packed together, but when 

 once disintegrated which is easily done by the fingers, it is 

 impossible to compress them together again. In colour it varies 

 from white to pale green and yellow, and is silky and flexible. 

 The more flexible varieties can be spun and weaved into textile 

 fabrics, and for this purpose the fibres need not be of long staple. 

 Its value depends upon its possessing lubricating properties and 

 upon its unchangeability when subjected to high pressures and 

 temperatures, and hence its largest employment in steam 

 machinery. It is spun and woven into cord and cloth for piston- 

 packing, and it is made into millboard and paper — the methods 

 of manufacture being similar to those employed in the manufac- 

 ture of textile fabrics and paper. It has been made into theatre 

 curtains and firemen's dresses, and its use as a nen-conductor 

 for boiler coverings and in gas stoves is well known. It forms 

 the chief material for packing fire-proof safes, and in America 

 is largely used as a fire-proof roofing felt. Asbestos fire-proof 

 cement, asbestos lubricant, and asbestos paint are also made 

 and used ; and latterly it is becoming of great value to the 

 electrician. Its uses appear to be rapidly increasing, and 

 although it is only 20 years since its manufacture was seriously 

 begun, it has already become a highly important industry. The 

 output of Canadian Asbestos was about 6,000 tons in 1889, 



