In this selection of the method of making gas-permeable channels in coal seams particular interest is associated with the physical structure of the coal from the point of view of the possibility of gas filtration through it. It has been established (1) that gas moves through coal seams via fissures of various types and also via macro- and micro-pores. The permeability of coals to gases is determined principally by their fissuring. The frequency and the degree of expression of the endogeneous fissures are closely connected with the stage of metamorphism and petrographic composition of the coals. Experimental work carried out by a number of authors indicates that the gas permeability of coals is maximal in the direction of the main system of endogeneous fissures.