Asbestos Fibre: Crude Chrysotile Hand-Cobbed into No. I and No. II (Cirkel, 1910)

Crude asbestos as the Quebec quarries dressed it by hand: rock holding long chrysotile fibre is broken with hand sledges, sieved, and then cobbed on steel plates with lighter hammers until the fibre is free, sorted into No. I (over 3/4 inch long) and No. II (5/16 to 3/4 inch), cleaned on sieves and bagged. Even so the crude still holds 5 or even 10 per cent of rock. Short fibre and all the screenings go to the mill for mechanical dressing. Source: F. Cirkel, Chrysotile-Asbestos (Ottawa, 1910), pp. 120-121. Picture: p. 120.