Preservative Treatment of Wood by Pressure Methods

_do_ air space air-seasoned Amer Assoc average moisture content Boiled under vacuum Boulton process checking coal-tar creosote coast Douglas-fir computed conifers considerably cubic foot diameter eastern hemlock effect empty-cell treatment factors fiber saturation point final vacuum full-cell process full-cell treatment green gross absorption hardwoods heartwood timbers heating medium heating period heating-medium temperature illus INCHES FROM SURFACE inches of mercury increase initial wood temperature kick-back lodgepole pine material maximum method mixtures moisture content obtained percent petroleum piling plants poles ponderosa pine pounds per cubic preliminary air pressure preliminary vacuum preservative oils preservative pressure pressure period Proc rate of temperature red oak retention round timbers sapwood sawed timbers seasoned wood shows side penetration softwoods southern pine southern yellow pine species specific gravity specimens springwood steaming period steaming-and-vacuum table 23 temperature change tion tracheids treated wood treating conditions treating pressure tyloses vacuum period viscosity water solutions Wood-Preservers zinc-chloride solution