A Treatise on Practical and Theoretical Mine Ventilation

100 cubic feet air circulating air in mines air passing air-column air-course air-current amount anemometer asphyxia atmosphere barometer brattice carbonic acid co-efficient coal coal-dust Colliery column cubic feet cubic foot cubic inches Davy lamp diameter discharge districts double downcast drifts engine equal explosion fan-drift feet of air feet per minute feet square fire-damp flame formula furnace gallery gases gauze hence horse-power inches of mercurial inches water-gauge increased ksv2 lamp length marsh-gas measured mechanical ventilators mercury miners morocco motive-column Mueseler lamp multiplied Nitric oxide number of revolutions oxygen perimeter piston pounds per square pressure per square pressure required Problem proportional quan quantity of air regulators required to overcome resistance revolutions per minute rubbing-surface safety-lamp sectional area shaft shutter smaller airway splitting square feet square foot temperature tion tity total pressure tube upcast velocity ventilating pressure volume of air weight ρα