66 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



Diameter and Annual Rings. 



Width of Annual Rings {Inches^. 



" The proportion of summer-wood to spring-wood was 

 approximately i3'4% and 86-6 % respectively. 



"Specific gravity based on oven-dry weights and volumes : — 

 Range: -26--34. Average •31. 



Percentage of Bark. 



At4oft.= 5-55% Thickness = -315 in. 



„ 6oft.= 8-48% „ =-395 „ 



„ 80 ft. = 10-14 % .. =-264 „ 



(Average for bark allowance = 8 %.) 



"The moisture percentage in the green condition from 



numerous readings taken at the mill along diameters at five 



different heights of the tree varied as follows: — 



Sapwood, i25%-22o% | Heartwood, 57 % - 92-8 % 

 "After the drums used in the laboratory investigation had 

 been stored for one month, the following observations were 

 taken along a radius of the drum at 40 feet : — 



"The distribution and variation of the moisture-content of 

 deciduous-leaved trees have been the subject of investigations 



