360 
FOXWORTHY. 
Comparative weights of Philippine and American ivoods — Continued. 
AMERICAN WOODS. 2 
Very heavy, 
Heavy. 
Moderately heavy. 
Light. 
Hickory. 
Ash. 
White cedar. 
White oak. 
White elm. 
White pine. 
Red oak. 
Sweet gum. 
White Spruce. 
Persimmon. 
Hard pine. 
Bald cypress. 
Osage orange. 
Cherry. 
Red cedar. 
Black locust. 
Birch. 
Hemlock. 
Hackberry. 
Maple. 
Redwood. 
Blue beech. 
Walnut. 
Oregon pine. 
Sour gum. 
Basswood. 
Coffee tree. 
Chestnut. 
Honey locust. 
Butternut. 
Tamarack. 
Tulip. 
Douglas spruce. 
Catalpa. 
Western hemlock. 
Buckeye. 
Soft maple. • 
Poplar. 
Sycamore. 
Sassafras. 
Mulberry. 
Willow. 
Resonance . — We have no commercial wood in the Islands which is 
suitable for making good sounding boards. Imported coniferous wood 
is usually used for this purpose in guitars and other stringed instruments 
of local manufacture, the backs and sides of the instruments being made 
of lanotan ( Bombycidendron campylosiphon (Tcz.) F. Will.), lanca 
( Artocarpus integrifolia L. f.) or other even-grained ornamental woods. 
Moisture content, shrinkage, seasoning . — Wood is much heavier when 
green than when dry, because of the large amount of water which it 
contains; air-dry it still holds 8 to 10 per cent of moisture and even when 
it; is kiln-dried there is usually some water left in it. It is exceedingly 
hygroscopic; a piece which has been very thoroughly dried will, if placed 
in a moist place, take up enough water to equalize its moisture content 
with that of the surrounding air. This capacity for taking up water is 
responsible for the swelling and warping of timber. The loss of water 
from the wood causes shrinkage and where this is uneven, checking. 
Seasoning . — The process by which water is gradually removed from 
wood is known as seasoning. In seasoning, certain chemical and phys- 
ical changes take place which render the wood stronger, more durable, 
and usually harder and heavier. The nature of these changes is rather 
imperfectly understood, hut it seems probable that certain materials 
contained in the pith-ray and wood parenchyma cells become changed 
into tannins, resins, and other substances which have a preservative and 
strengthening effect. When properly seasoned a wood is always stronger 
2 The classification" of American woods was taken from Roth’s Bull. Timber., 
U. S. Bur. of Forestry (1895), 10. 
