406 
Burr weighed 65:58 lbs., or 60°53 Ibs. per cub. ft. But after 
seasoning for two years the weights per cub. ft. were 3129 
and 35°69 lbs., respectively, the whole set averaging out at 
32°96 Ibs. per cub. ft. The 6 in. x 4 in. pieces of Pinus 
canariensis weighed on the average 65°42 lbs., or 60:4 lbs. per 
cub. ft. on receipt at the Laboratory, but reduced finally to 
41°83 lbs. per beam, or 38°61 lbs. per cub. ft. Some of the 
insignis beams from Mount Burr contained as much as 158 
per cent. of moisture, caleulated on the dry weight of the 
timber, but the moisture contents of all the timbers had fallen 
to about 11 or 12 per cent. by March, 1919. 
Even when dried to approximately the same percentage 
of moisture contents there was a considerable difference in the 
weights per cub. ft. of the timber from the three trees from 
which the insignis beams were cut, and an analysis of the 
beam tests for the 20-year-old tree from Wirrabara the 
strengths were very nearly proportional to the densities of 
the timber, as the following table shows: — 
Ratios or DENSITIES AND STRENGTHS Or Pinus insignis. 
Timber from Different Trees. : 
From From 
Wirrabara. Mount Burr. 
30 years 20 years 33 yea 
old. old. old. 
Ratio of densities... zii : ; ro Mis 
Ratio of strengths in compres- 
sion along the grain TY oe oe eo CDM 
Ratio of shearing strengths ... Io c DM 5 
Ratio of strengths of beams Po IgM. LE 
Similar results, however, were not found to apply to the 
maritima tests. Here again the timber from Mount Burr was 
tests, and determinations of 
pression both longitudinally 
