TREES FOR WATER CATCHMENT AREAS 137 
west wind or by the sea spray, and attains a gigantic size, 
rivalling in this respect the Douglas fir, which it almost 
equals in rapidity of growth. It grows on poorer and 
wetter soil than the latter tree. The timber is like white 
deal, is entirely without taste or odour, and is cut in 
Alaska and British Columbia for making butter-casks, 
packing-cases for fruit, wood-pulp, and pianos, as well as in 
ordinary house and boat building. Imported now under 
the name of silver spruce, its strength, stiffness, lightness, 
and elasticity make it the most suitable wood in aeroplane 
construction. The climate where it grows is similar to our 
own, described as “mild and uniform, with heavy rainfall, 
high humidity, and dense fogs; summers generally mild 
and winters not severe. The temperature drops to — 35° F. 
towards its northerly limit; while towards the south and 
along the coast light frosts occur and temperature falls to 
ZeTO.” 
Sitka spruce is extremely vigorous in growth, being only 
surpassed by the Douglas fir at all ages, and by the Japanese 
larch in the young stage. It is especially adapted for 
planting in difficult conditions of soil, where other species 
would be a failure. It grows well in wet ground, in acid 
peaty soil, in exposed situations, and at high altitudes. It 
is at home in the districts bordering on the western coast, 
where there is a heavy rainfall and a constant prevailing 
wind. It does not thrive on dry gravelly soils; but in 
general it is comparatively indifferent to soil, and makes 
excellent growth in all parts of the British Isles. It is the 
species that should be selected for planting in wet places in 
most plantations; and it should be used extensively at high 
altitudes in the heather moorland. The tree is excellent 
in form, making a beautiful straight stem (Fig. 26). The 
seedlings are slow in growth during the first two years, and 
require protection from frost. Transplanted at the beginning 
of the third year, they may be planted out when they have 
completed their third or fourth year. Larger plants, 3 to 4 
feet high, can be safely moved, and should be preferred in 
low-lying situations liable to frost. After the Sitka spruce 
