28 BULLETIN 333, U. S. DEPARTMENT OF AGRICULTURE. 
timbers are teak, greenheart, lignum- vita 1 , etc. " Karri " {Eucalyp- 
tus diver sicolor) and "jarrah" (E. ??wrginata) , of Australia, are 
resistant although not immune to attack by termites. 
REMEDIES. 
LOCATIOX OF DAMAGE TO "WOODWORK IX BriLDIXGS. 
The point of emergence of the flying termites may indicate approx- 
imately the location of the infested timbers; if the insects are not 
observed swarming, large numbers of the dead winged adults or the 
discarded wings will be found near by. Frass and earth thrown out 
of crevices through which the insects emerge are also evidence. In 
efforts to stop further damage by termites in buildings it should be 
realized that the numbers of these insects may be constantly recruited 
from some undiscovered, outside central colony. The destruction of 
the winged, colonizing adults at the time of the emergence, while ad- 
visable in preventing the establishment of potential new colonies, is 
of no value in eradicating the insects infesting the woodwork. 
Another indication of infestation is the presence of longitudinal 
earthlike tubes, of small diameter, constructed on foundation timbers 
or other woodwork, or over the surface of stone, brick, or other im- 
penetrable foundation material from the ground to the woodwork. 
Drenching the ground — where these tubes originate — with kerosene 
oil will afford relief. A prompt examination of the foundation tim- 
bers, such as beams and joists in contact with the ground, should be 
made to determine the approximate point of entrance of the insects 
and the extent of the damage already accomplished. It may be nec- 
essary to tear up the flooring and other woodwork to accomplish this. 
The foundation timbers and interior woodwork found damaged 
should be removed and burned and the ground where they were set 
drenched with kerosene oil. 
ROCK FOVXDATIOXS AXD WOOD PRESERVATIVES. 
The main point is to prevent the insects from gaining access to the 
woodwork from colonies in the ground, either by means of substitut- 
ing rock or concrete foundations and concrete or tile flooring in the 
basement or by protecting the foundation timbers in contact with 
the ground by impregnation of the wood with coal-tar creosote. 
It is very rarely possible to find and destroy the external colony, 
and it may be necessary to replace the foundation of the buildings 
with walls and floorings of stone, concrete, or other form of rock 
composition, and this is the most permanent and complete preventive. 
In the case of the National Museum buildings, the Carnegie Insti- 
tution of Washington, and several private edifices in Washington, 
