(■■■:— 4,

of not less than 1 in. to 2 chains, and must be prepared by or under the supervision of a surveyor possessing the prescribed qualifications; and the manager shall, whenever requested by any Inspector, accurately mark on such plan the progress of the workings of the mine, with the ventilation thereof clearly shown up to the time of such request, and shall allow such Inspector to examine and take a copy or tracing thereof. (2.) That power be given the Inspectors to "require that all mechanical ventilation appliances be run constantly, or for such time as he thinks necessary, in all cases where he considers the condition of the mines require it, either for ventilation or reduction of temperature; and in all cases that such ventilation appliances be started and continuously run to their usual capacity for two hours before men start to work in the mine. (3.) The Inspector shall have power to order, if he considers it advisable, that, for the improvement of ventilation (a.) All rises be put up on the three-compartment or box system : (b.) Two distinct air-passes, of dimensions specified by him shall be carried up in all stopes, and maintained solely for ventilation: J (c.) That the height of rises be limited to a height specified COAL-MINES. Special attention has been devoted by us to the ventilation of coal-mines, 1 ? to state that we found that the majority of the collieries stantinteTbvT 7! lw v ? To a certain extent this opinion is substantiated by the fact that during the past fifteen years only one life has been lost as the result of an explosion of firedamp. ' by d ffl eCt "° ticed > v us was inadequate distribution of the air tLof llrS ft ms " fficie + nt use of air-stoppings and brattice, and the installation of fans of insufficient power m case of extension of the workings or during isTroduced bt ff *"? *"*! -° f proportion! ventlK is produced by fans of modern type, thirty fans being at present installed the type most favoured being the " Sirocco," » Waddle," « Sturtevant," and "Hayes Existing Standard of Ventilation. in nJw/SK 118 1S thG f a ff or -\S eneral for ventilation of coal-mines Act 1908 1 '• Prescribed by subsection (1) of section 40 of the Coal-mines depth of the coal-seams high temperatures or extreme noFoZr

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