A Treatise on Practical and Theoretical Mine Ventilation

air circulating air in mines air passing air-column air-course air-current amount anemometer asphyxia atmosphere barometer brattice carbonic acid coal coal-dust Colliery column cubic feet cubic foot cubic inches Davy lamp diameter discharge districts double downcast drifts employed engine equal explosion fan-drift feet of air feet per minute feet square fire-damp flame formula furnace gallery gases gauze height hence horse-power inches of mercurial inches water-gauge increased inflammable ksv2 lamp length marsh-gas measured mechanical ventilators mercury method miners morocco motive-column Mueseler lamp multiplied 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 Suppose temperature tion tity total pressure tube upcast velocity ventilating pressure volume of air ρα