452 Forestry Quarterly. 



Dry Rot in Factory Timbers. Inspection Department of the 

 Associated Factory Mutual Fire Insurance Companies, 31 Milk 

 St., Boston, Mass. 1913. Pp. 34. Illus. 



A brief summary of the results of investigating several thou- 

 sand beams in buildings, more than one hundred of which were 

 "examined chemically and microscopically." The pamphlet deals 

 exclusively with southern yellow pine timbers, since this wood 

 is the only one now used to any extent in the East for heavy mill 

 frames. Attention is called to the great confusion in the commer- 

 cial names used to describe the southern yellow pines, and to the 

 indefiniteness of some of the terms used in rules for the inspection 

 of timbers. The difficulty of identifying the various southern yel- 

 low pines is also brought out. 



After discussing briefly the various causes of dry rot and the 

 influences which encourage it, the pamphlet mentions some of the 

 preservatives which have been used to arrest decay. 



The following observations are made : 



1. "The percentage of resin in hard pine can be taken as an 

 index of its power of resistance to dry rot. 



2. "Hard pine lumber 12 inches square or larger is practically 

 not obtainable with sufficient natural resistance to withstand 

 fungus in a moist atmosphere. 



3. "The non-resinous and sappy hard pine, which is obtainable 

 is not safe to use for the important parts of a building without 

 antiseptic treatment. 



4. "Holes through columns, narrow spaces between beams and 

 hollow spaces in floors or roofs are of no value in preventing dry 

 rot, and serve to rapidly spread it to all susceptible material. 



5. "Heating a new building to 115° F., for twenty-four hours, 

 or more, several times has a value well worth its cost in preventing 

 serious dry rot damage. 



6. "Of the various antiseptic treatments in practical use at pres- 

 ent, corrosive sublimate appears to be the best adapted to mill 

 timber. Modification of the present process may be necessary 

 when deeper penetration is required." 



R. C. B. 



