If the desired proportions are not attained naturally, the formation and deposition of coaldust may occasionally be considerably lessened by the adoption of simple precautions, such as: watering at the face, so as to lessen the dust deposits in the return airways; washing the tubs, and using sound tubs that will not shed so much dust in the haulage roads; and limewashing, which fixes the dust on the walls and schistifies the floor.