2 BULLETIN 1053, U. S. DEPARTMENT OF AGRICULTURE. 



humidities and moderately high temperatures prevail throughout the 

 year. Such conditions provide a very favorable environment for the 

 development of wood-decaying fungi, and this condition is ag- 

 gravated by the quality of timber which has been on the market in 

 recent years. The timber formerly used in mill construction consisted 

 in many cases of white pine and white oak, both of which are highly 

 durable woods. In more recent years, however, these timbers have 

 been supplanted largely by southern yellow pine, spruce, and hem- 

 lock. High-grade resinous longleaf pine has given good service 

 under exacting conditions, but the inferior grades of pine, often of 

 more rapid growth and frequently containing a high percentage of 

 sap wood, have not proved satisfactory in parts of buildings where the 

 conditions are favorable for decay. Likewise, spruce and hemlock 

 have given poor service under similar conditions. Furthermore, 

 such timbers may be left in the open for protracted periods, exposed 

 to the weather and infection by fungi, or may be put in buildings in 

 a partially seasoned condition, and after a short period replacement 

 is necessary, involving not only the direct expense of repairs but also 

 loss of operating time. 



Hoxie (££, p. 2) 2 reports that 30 cases of rot of greater or less 

 magnitude have come to his attention within three years. He states 

 that " several million feet of lumber were involved, and in some of 

 the worst cases the safety of important structures was menaced. 

 * * * The direct money loss to Mutual members (Associated Fac- 

 tory Mutual Fire Insurance Companies, Boston, Mass.) * * * is 

 undoubtedly many thousand dollars each year, in addition to the in- 

 creased life and fire hazard from loss of strength and greater com- 

 bustibility of rotting structural timbers." 



The following specific examples from Hoxie's records may be of 

 interest to show the magnitude of the loss. In a Connecticut mill 

 the roofs of weave sheds, built in 1906 and 1909, were so seriously 

 rotted in 1916 that it was estimated that 40,000 feet of plank would 

 be necessary for repairs. The older roof in many places was not 

 safe to walk upon and had settled so that there were hollows sup- 

 ported practically only by the tarred paper. In one Massachusetts 

 cotton mill built in 1900, 85 per cent of the roof planking and a 

 large proportion of the floor supports had rotted and had been re- 

 placed by hemlock, in some cases twice between 1908 and 1914. It was 

 found that hemlock, put in green, lasted about two years. It was 

 estimated that over 1,000,000 feet of lumber had been used in the 

 construction of this mill in 1900, at a cost of $30,000, and the re- 



2 The serial numbers in parentheses (italic) refer to " Literature cited " at the end 

 of this bulletin. 



