1038 



ARBORETUM ET FRUTICETUM BRITANNICUM. 



of the tree is slow when young, but 

 rapid after it has attained the age of 

 10 or 12 years. Cones with fertile 

 seeds are seldom produced before the 

 tree has attained its 40th year ; though 

 cones without seeds often appear be- 

 fore half that period has elapseil. The 

 female catkins are often produced for 

 years together, without any males ap- 

 pearing on the same tree. Young 

 trees are apt to lose their leaders l)y 

 very severe spring frosts ; and, hence, 

 we frequently find old silver firs with 

 forked trunks and branchy iieads. The 

 wood of the silver fir is elastic, and the 



1938. P. pectinMa. 



colour is whitish. The grain is 



irre- 



gular, as the fibres which compose it 

 are partly white and tender, and partly 

 yellow, or fawn-coloured, and hard. 

 The narrower the white lines are, the 

 more beautiful and solid is the grain 

 of the wood. The wood of a tree 80 

 years old weighs 66 lb. I-i oz. per 

 cubic foot green, and 41 lb. 3 oz. when 

 dry ; while that of a tree 40 years old 

 weighs only 37 lb. 9 oz. when dry. It 

 shrinks considerably in drying, like all 

 white woods. It is used for planks 

 and carpentry of all kinds, for the 

 masts of small vessels, for joists and 

 rafters, and for building the boats 

 used for navigating rivers. It is said 

 to endure a long time when used as 

 piles, and to be much emplojed in 

 Holland for that purpose. From the 

 resin of this tree are manufactured 

 Strasburg turpentine, colophony, and 

 white pitch. The silver fir, like all the 1939. p.pociinMa. 



other ^bietinae, will attain a large size 



on soils of a very opiwsite description ; but a loam, rather rich and cieep than 

 otherwise, appears to suit it best. The silver fir requires a low situation, 

 comparatively with the spruce fir, not being nearly so hardy as that tree, either 

 when in the nursery or full grown. The cones, which are produced in abun- 

 dance in Britain, are apt to shed their seeds in spring ; they ou^ht to be gathered 

 in October or November, and kept in a dry place till the sowing season. The 



