The Birmingham age-herald., 1908-10-26

watering which occasionally sprinkles the floor only and leaves dry the dust on the walls and the timbers of the road ways is useless, and is also dangerous In that it may generate an unwarranted feel ing of security against an explosion.
 "In any mine where as ugh as per cent of gas can be detected by suitable method, only locked safety lamps of an approved type should be used, so long as such condition exists or is likely to re- cur.
 "Al safety lamps should be maintained in good condition, cleaned, filled, kept in a special room, at the surface, and care fully examined both when delivered to the miner and when returned by him at the close of each days work defective safety lamp is especially dangerous be- cause of the false feeling of security it engenders In the filling of lamps with benzne or other low-fash oils, which should always be done at the surface, spe- cial precautions against fire or explosions should be taken
 Electricity in Mining.
 ''Electrlcity in mining operations offers so many advantages, and has been so generally adopted, that no reasonable ob- lection can be made to it's use under proper restrictions. The electrical equip ment, however, should be installed, main tained and operated with great care, and so safeguarded as to minimize danger from fire or shock. The fact that the effectiveness of some insulating materials is soon destroyed in most mines should not be lost sight of.
 I've recommend the following precau- tions: For distribution underground the voltage should not exceed $50 direct cur rent or 300 alternating current, these volt ages being intended for transmission to machinery operating at 300 volts direct current and 40 volts alternating cur rent respectively. Even lower voltages are preferable. The trolley wires should be installed in such manner as to render shocks least likely, that is, either high enough to be beyond reach, or placed to one side of the track and properly pro- tected.
 ..Where current of potential or more than $50 volts is employed for transmits sion underground it should be transmitted by means of a completely insulated cable; and where a lead or armored covering is used such covering should be grounded
 "In all mines having electric installa- tion special precautions should be taken against the setting on fire of coal or timber. Inclosed fuses or cut-outs are recommended, and each branch heading should be so arranged that the current may be cut off when necessary.
 ..No live electric wire should be per mitted in that part of any mine in which gas is found to the amount of 2 per cent.
 The Safety Lamp.
 .'In all mines producing gas in dam gerous quantities, as indicated by safe- ty lamp, which will detect per cent of gas, the working places should be ex- amined for gas by a qualified man, using such lamp, immediately before any cleo tric machine is taken or operated there.
 .In all new construction, shaft lining and superstructures about the entrance of the shaft Cor slopes or drifts) should be built as far as practicable of non-com- bustible materials. About the entrance to mines, every possible precaution should be taken to prevent fires or the injury of the equipment for ventilation and haul age. Ventilation fans should be placed to one side of the mine opening; and hinged doors or light timbering should render easy the escape of the explosive force in direct line of the shaft or slope. Proper precaution should be taken for immediately preventing the entrance into.