Missouri Revised Statutes Title XVIII. Labor and Industrial Relations § 293.340. Coal mines with twenty-five miners, signalmen required--hoisting cages furnished, when--penalty

1. The owner, agent or operator of all coal mines employing twenty-five or more men, shall cause a competent person to be stationed at the top of the shaft, and a competent person to be stationed at the bottom of the shaft, whose duties shall be to answer all signals for the lowering or hoisting of men in the shaft, and to keep watch over, and control of, such signals while men are being lowered or hoisted in the shaft;  the persons so appointed to look after said signals shall be at their posts of duty at least thirty minutes before the hoisting of coal has commenced in the morning, and shall remain after the hoisting of coal has ceased in the evening at least thirty minutes.  Whenever eight persons shall present themselves at the bottom of the shaft and after having finished their day's work, or otherwise having been prevented from working, an empty cage shall be furnished the same on which to ascend.

2. Any owner, agent or operator of coal mines in this state, who shall knowingly violate any provisions of this section, shall be deemed guilty of a misdemeanor, and upon conviction shall be punished by a fine of not less than one hundred dollars nor more than three hundred dollars for each offense, or by imprisonment in the county jail for not less than thirty days nor more than ninety days, or by both such fine and imprisonment.