458 JOURNAL OF FORESTRY 



.48 Lumber and timber associations. 



.5 Wood technology. 



.51 Timber physics. (For different species see .1476.) 



.511 Stracture and identification of wood. (See also .11.) 



.512 Physical properties of wood. 



.513 Mechanical properties of wood. Timber testing. 



.514 Chemical properties of wood. (See also .436, .4411, .442, .443, .446, 

 and .447.) 



.52 Conditioning of wood. 



-521 Air seasoning. (See also .4221.) 



.522 Kiln drying. (See also .4222.) 



.53 Wood preservation. 



.531 Preservatives. 



.532 Methods and costs. 



.533 Treating plants and apparatus. 



.54 Wood substitutes. 



.6 Forest engineering. (For logging engineering see .41.) 



.61 Surveying. (For logging railroad surveying see .41221.) 



.611 Land surveying. Forest boundary surveys. (See also .7321.) 



.612 Topographic surveying. (See also .7321.) 



.62 Mapping. (See also .7321.) 



.63 Construction engineering. (For logging and forestation machinery and 

 equipment, logging railroad, sawmill, paper mill, and seed extrac- 

 tion plant construction and equipment, see .41, .25, .41221, .42, 

 .431, and .2513, respectively.) 



.631 Roads. 



.632 Trails. 



.633 Bridges. (For logging railroad bridges see .41221.) 



.634 Telephone lines. 



.635 Buildings. 



.636 Fences. 



.637 Lookout towers and special protective works. 



.64 Hydraulic engineering (including reservoirs, dams, and conduits). 



.641 Irrigation. 



.642 Domestic water development. 



.65 Hydroelectrical engineering. (See also .97113.) 



.66 Camp management. 



.661 Camp equipment. 



.662 Commissary and dietary. 



.663 Camp sanitation. 



.664 First aid and medical data. 



.665 Veterinary data. (See also .8487.) 



.7 Forest Management. 



. 7 1 Forest mensu ration . 



.711 Measurement of logs. 



.7111 Board measure. Log rules. Scaling. 



.7112 Cubic measure. 



.712 Measurement of lumber. (See also .423.) 



