324 A HANDBOOK OF CONIFERS 



" Compression, strength across grain at elastic limit, 290 lb. 

 per square in. 



" Compression, crushing strength with the grain, 1,980 lb. per 

 square in. 



" Shearing, strength with the grain, 590 lb. per square in. 



" Bending, modulus of rupture (breaking strength), 4,200 lb, 

 per square in. 



" Bending, modulus of elasticity (stiffness), 830,000 lb. per 

 square in. 



"Hardness, weight required to haK imbed a 0-444 in. steel 

 ball, 245 lb." 



It should be compared with white spruce rather than with 

 Sitka spruce, and may be used for similar purposes. Considerable 

 quantities of timber are available from British Columbian and 

 Western U.S.A. ports. It will probably afford one of the great 

 sources of pulpwood in the future. 



The bark is said to be rich in tannin and to be exploited to 

 some extent for tanning purposes. 



Engelmann's spruce is of no commercial importance in Britain, 

 but is sometimes cultivated in gardens, the glaucous-leaved form 

 being most popular. It succeeds best in districts where the 

 atmospheric conditions are moist, and where the soil is loamy 

 and never becomes dry. It is hable to injury by both Chermes 

 ahietis and Aphis abietina, which see under the generic description. 



P. Engelmanni is being planted in Switzerland for protective 

 work at high elevations. Near Pontresina, at 8,000 ft. and higher, 

 it is giving better results than native trees. It might be worth 

 trying under forest conditions in the Scottish Highlands above 

 the natural tree hmit. At lower elevations in its native country 

 this species is usually confined to north slopes and valleys where 

 the soil is constantly moist ; at higher altitudes it is more gen- 

 erally distributed, but only where the ground is moist. It is 

 found in pure stands and in mixed forests ; withstands a good 

 deal of shade and makes a good recovery after many years of 

 suppression. Good seed-years occur triennially and the seed is 

 said to possess a high rate of germination. 



Sudworth, The Spruce and Balsam Fir Trees of the Rocky Mountain Region, 

 10-14 (1916). 



Picea excelsa, Link. (Fig. 71.) 

 Common Spruce. 



Abies excelsa, De CancloUe ; A. Picea, Miller ; A. rubra, Bauhin ; 

 Picea vulgaris, Link ; Pinus Abies, Linnaeus ; P. excelsa, Lambert (not 

 WaUieh). 



European Spruce ; Norway Spruce ; Spruce Fir ; Violin Wood ; White 

 Deal (in part) ; Wliite Fir ; White Pine. 



A tall tree attaining in Cent. Europe a height of 200 ft. and 

 a girth of 15-20 ft. In Britain it often becomes 120 ft. or more 



