98 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



being sent. From each piece four beams were cut for the 

 transverse tests and eight specimens for the compression tests, 

 the dimensions of the specimens being those adopted for the 

 aeroplane research work described in the earlier paper. For 

 the compression tests the cross-section at one end of the plank 

 was marked out into eight equal rectangles, and a length of 

 12 inches was sawn off; this length was then sawn into eight 

 slabs, and a compression specimen was turned out of the 

 central 3-inch length of each of these small slabs. The four 

 beams for the transverse tests were similarly prepared by 

 sawing off the plank a length of 48 inches, and dividing this 

 into four pieces, each 3 J inches wide and i| inch thick, these 

 pieces being then planed to the final cross-sectional dimensions 

 2 inches by i inch. As soon as each specimen was tested it was 

 put into an air-tight tin case and sent to the botanical depart- 

 ment of the University, my colleague, Prof. Wright Smith, 

 having kindly arranged to have the moisture content of each 

 specimen determined by a member of his staff. The results 

 obtained in these tests are given in the summary tables below : — 



Transverse Tests. 

 Scots Pine, grown in Atholl Forest. 



Plank 



No. 

 I 

 2 



Mean Maximum 

 Compressive Stress 



Mean Number 

 of Annual Rings 



lb. per sq. in. 

 7466 

 6186 



per radial inch. 

 17-0 



8-0 



Mean Moisture 



per cent. 

 19-57 



1 3 "95 



Scots Pine, Foreign Grown. 



7299 

 6214 



13-5 

 19-5 



13-12 

 14-36 



