THICK SEAM MINING IN CANADA.

Because coal in Canada occurs in seams of many different thicknesses and positions and between rock strata of various strengths it has been necessary to employ many different methods to mine thick seams. Variations of room and pillar, longwall and caving methods have been used. However, coal recovery has often been low and fires have occurred. Where conditions are favorable the hydraulic mining method appears attractive. The author surveys the use of thick seam mining in Canadian surface and underground mines.