52 



ECONOMIC WOODS OF THE UNITED STATES 



TABLE III— Continued 



Species Sp. Gr. 



Abies magnifioa 47 



Magnolia acuminata 47 



Populus grandidentata 46 



Chamsecyparis lawsoniana 46 



Picea nigra 46 



Abies nobilis 46 



Taxodium distichum 45 



jEsculus glabra 45 



Tilia americana 45 



Castanea dentata 45 



Catalpa catalpa 45 



Salix nigra 45 



Pinus flexilis 44 



Acer negundo 43 



Picea sitchensis 43 



jEsculus octandra 43 



Salix discolor 43 



Tilia heterophylla 43 



Tsuga canadensis 42 



Liriodendron tulipif era 42 



Abies amabilis 42 



Sequoia sempervirens 42 



Catalpa speciosa 42 



Pinus albicaulis 42 



Species Sp. Gr. 



Pinus coulteri 41 



Pinus murrayana 41 



Populus heterophylla 41 



Juglans cinerea 41 



Tilia pubescens 41 



Picea alba 41 



Populus tremuloides 40 



Libocedrus decurrens 40 



Asimina triloba 40 



Alnus oblongifolia 40 



Pinus glabra 39 



Pinus monticola 39 



Pinus strobus 38 



Abies balsamea 38 



Populus trichocarpa 38 



Thuya plicata 38 



Pinus lambertiana 37 



Abies concolor 36 



Populus balsamifera 36 



Abies grandis 35 



Picea engelmanni 34 



Thuya occidentalis 32 



Sequoia washingtoniana 29 



Leitnena floridana 21 



References 



Roth, F. : Timber, Bui. 10, U. S. Div. Forestry, pp. 25-28. 



Sargent, C. S. . Forests of North America, Part 9, Tenth Census of the U. S., 



Washington, 1884, pp. 248-251. 

 Gayer, K: Schlich's Manual of Forestry, Vol. V, 1908, pp. 50-65. 

 Nordlinger, H. : Die Technischen Eigenschaften der Holzer, Stuttgart, 1860, 



pp. 115-227. 



WATER CONTENT OF WOOD 



Water occurs in living sapwood in three states, viz., (1) in 

 the protoplasmic contents of the cells, (2) in the cell walls, and (3) 

 as free water wholly or partially filling the lumina of cells, fibres, 

 and vessels that have lost their contents. In heartwood water 

 normally exists only in condition (2). In the fresh sapwood of 

 Pinus strobus, which may be taken as fairly typical, water com- 

 prises about half of the total weight and is distributed approx- 



