A survey was made of the discolorations occurring in Sitka spruce wood, and toughness tests were made on specimens that included discolorations of unknown or doubtful significance.
A survey was made in Oregon and Washington of the discoloration occurring in noble fir and Western hemlock wood, and the present data are presented as an aid in the inspection of these woods for aircraft and other high-grade lumber.
Recommendations, based on strength tests of similar discolorations in spruce...