: Perhaps it is only the glue that is weak (the types of failure were
: different).

: But in any case we are stuck using wood which has properties that very with
: direction.

Weak glue could not explain the observed behavior. The loading curves were completely different for the two orientations tested. In some cases, failure did occur along glue lines but in the other cases glue-lines remained unbroken. Buckling of the skin in compression was common to these specimens. Yes, the mechanical properties of wood do vary with orientation.