LONGITUDINAL PERMEABILITY OF SAPELE (ENTANDROPHRAGMA-CYLINDRICUM) TO AIR

The longitudinal apparent air permeability of sapele heartwood was det ermined by flow measurements with pressure gradients ranging from 5.3 to 8.9 kPa for the lowest mean pressure used (100 kPa) and from 12.0 t o 14.4 kPa for the highest (250 kPa). These data were used to calculat e the capillary radius limiting permeability and the specific permeabi lity. The value of the limiting capillary radius was confirmed by merc ury-porosimetric determination of the modal capillary radii, which are tentatively interpreted in terms of the possible structure of sapele xylem vessels.