LABOR,CODE,LAB,DIVISION 5,SAFETY,EMPLOYMENT,ENACTED,MINING,INDUSTRIES,CHAPTER,UNDERGROUND,TELEPHONES,MINES,THE STATE,DEPTH,FIVE HUNDRED,FEET,REACHED,TELEPHONE,SYSTEM,SHALL,OWNERS,THE MINE,STATIONS,LEVEL,BELOW,COMMUNICATING,STATION,THE SURFACE,FAILURE,REFUSAL,LESSEE,INSTALL,MISDEMEANOR,