Sec. 949. [=Relating to construction of new mines.=] Any person, firm or corporation beginning the opening of a mine, whether such person, firm or corporation be the owner, lessee or agent of the property upon which such mine is located, or not, shall observe the following in the construction of such mine:  If the opening be a slope or vertical shaft, no explosive used therein shall be fired by means of a squib or fuse after the same is extended more than twenty-five feet from the surface, and thereafter and until the slope or shaft reaches the seam, and the entry or landing be extended beyond a breakthrough or other place driven at right angles thereto, no explosive shall be fired except by means of an electric battery operated from the surface after all persons are on the surface.  A substantial structure to sustain sheave wheels or pulleys, ropes and loads, shall be provided, and if the opening be a shaft, the same shall be placed at a height of not less than twenty feet above the tipping place.  A landing platform shall be arranged in such manner that no material can fall into the shaft while the bucket is being emptied, and in no case shall the shaft be sunk to a depth of more than thirty feet without such structures.  If the bucket used for hoisting material is to land on a truck, the track on which said truck is operated, and the platform, shall be so constructed that material cannot fall into the shaft.  Rock and coal shall not be hoisted from a shaft or slope except in a bucket or cage attached to the rope by a safety hook, clevis, or other safe attachment, and the bucket or cage securely locked so that same cannot tip or empty while being hoisted.  The rope shall be fastened to the side of the drum, and not less than three coils of rope shall always remain on the drum.  After the shaft reaches a depth of one hundred feet, the same shall be provided with guides and guide attachments, applied in such a manner as to prevent the bucket from swinging while being lowered or hoisted, and said guides and guide attachments shall be maintained at a distance of not more than seventy-five feet from the bottom of the shaft.  The sides of all shafts shall be properly secured for safety, and no loose rock or material shall be allowed to remain on any timber in the shaft after each blast.  All loose timber, tools, and materials, shall be kept away from the top of the shaft, so as to reduce the danger of same falling down the shaft.  Where explosive gas is encountered, the person in charge shall see that the shaft or slope is examined before each shift of men enter to work, and before the men descend after each blast.  Provision shall be made for the proper ventilation of the slope, or shaft, so that persons working therein will have the necessary air.  An efficient brake shall be attached to each drum of an engine used in hoisting material and persons, and all machinery, ropes and chains connected therewith shall be carefully examined once each twelve hours.  Not more than