The Ventilation of Coal Mines

according air column air passing airways area and rubbing brattice Brevet calculation circulate cloth co-efficient of friction common pressure cube root cubic feet Degs diameter dip and rise Divisions effect of split Engineers feet of air feet per minute figures in column final velocity fire damp foot of rubbing formula gases given Illustrated intake ksv² long split mines motive column multiplied NOSTRAND'S PUBLICATIONS obtained pass equal quantities Plympton pounds per square power required PRESCOTT pressure or power pressure required producing the ventilation proportion QUALITATIVE CHEMICAL ANALYSIS quantity of air quantity passing relative powers relative pressures required to pass result return air revised and enlarged rise split road 6 ft rubbing surface rule specific gravity splits subject splitting the air square foot Steam temperature tion typical road U. S. Navy unequal splitting upcast shafts ventilating pressure water gauge weight yards long ρα ха