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 
sapwood, 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 (%4-, 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. 
