Exotic Conifers in Britain. 



34i 



On area No. 1 there were 18 trees, and on area No. 2, 25 

 trees, the mean for the whole wood being probably not less 

 than 210 per acre. In order to facilitate accurate comparison 

 with Dr. Schlich's figures of 1888 we may assume the same 

 average number of trees per acre, namely, 202. In the case of 

 area No. 2 four of the trees were exceptionally small, and in a 

 wood planted sufficiently close in youth they would certainly 

 have disappeared in the thinnings. The total sectional area of 

 the stems at feet was 290 and 300 feet respectively per 

 .acre, mean say 295. From these figures the mean diameter of 

 the trees of area No. 1 works out at 17*2 inches (girth, 4 

 feet 6 inches) ; while in the case of area No. 2 it is 14*8 inches 

 (girth, 3 feet ioj inches). The mean diameter may be put 

 at 15*9 inches, equal to a girth of 4 feet if inches. In 1888 

 Dr. Schlich found the average diameter to be 12 inches, his 

 sample tree being a quarter of an inch less. 



Some trees having last winter been blown down towards the 

 margin of the wood, Mr. Pitcaithley measured a typical one 

 in 6 feet sections, the details of which are given below. The 

 total length was 80 feet, the diameter of 3 inches being reached 

 at J\\ feet. The true cubical contents work out at 58*93 feet, 

 or 4676 feet calculated by quarter-girth measure : — 



No. 1.— Sample Douglas Fir, Measured 1903. 







Mean 



Volume of 



Mean Cir- 



Volume of 





Length of 



Diameter of 



Wood in 



cumference 



Wood by 



No. of 



Section. 



Sections. 



each Section. 



of Sections. 



Quarter-girth 

 Measure. 



Section. 

















Feet. 



Inches. 



Cub. Feet. 



Ft. 



In. 



Cub. Feet. 



1 



6 



18-0 



io-6o 



4 



8| 



8- 3 i ' 



2 



6 



16*2 



8-59 



4 



3 



677 



3 



6 



15*3 



7-66 



4 



0 



6°OQ 



4 



6 



H'5 



6-88 



3 



9* 



5-41 



5 



6 



13-5 



5 "96 



3 



6^ 



4-68 



6 



6 



12-6 



5-19 



3 



3i 



4.08 



7 



6 



n-6 



4-40 



3 



oh 



3*45 



8 



6 



105 



3-6i 



2 



9 



2-84 



9 



6 



9-2 



277 



2 



4| 



2-15 



10 



6 



7-6 



1-89 



2 



0 



1-50 



11 



6 



5'5 



•99 



1 



5i 



077 



12 



si 



3-6 



•39 



0 





0-30 



Total 



7ii 





58 '93 







4676 



