‘‘WHITE ANTS’’ AS PESTS IN THE UNITED STATES. 162) 
floor join at right angles; termites often come up through cracks 
between walls and flooring. . 
The publications of the Department of Agriculture should be con- 
sulted in regard to the specifications for the proper proportioning, 
mixing, and placing of concrete.1 Recent tests conducted by the 
Office of Public Roads and Rural Engineering have demonstrated 
the value of mixing a heavy mineral residual oil with Portland cement 
paste to form an admixture ? almost perfectly nonabsorbent of water 
and therefore an excellent material to use in damp-proof construc- 
tion, as flooring, etc. Where the various patent or noiseless floorings 
are used on the ground floor, they should always be laid over a con- 
crete base, especially if they contain wood fiber as a constituent. 
Bungalows or frame buildings in the country which have no cellar 
should be raised from the ground on stone foundations to a height 
which will allow light and air to penetrate beneath. 
Where stone or concrete foundations are impracticable, timber 
impregnated with coal-tar creosote should be used. Untreated 
beams should never be laid on the earth nor imbedded in moist con- 
crete, since they will rot, even if they do not become infested. 
Beams in no case should be completely surrounded with mortar 
or brick; there should be an air space around the beams so as to 
permit air circulation. Beams should not be set in earth or in moist 
concrete but should be set on rock or dry conercte. 
The supports of the woodwork of coal bins in basements or cellars 
should not be set in the ground but should rest on concrete. Window 
sills and frames in the basement or cellar should be laid over con- 
crete, and the woodwork should not come in contact with the ground. 
There should be no untreated wood in contact with the ground through 
which white ants can come up from subterranean galleries. Com- 
plete dryness of foundation timbers and basement walls and flooring 
is an important means of rendering buildings safe from attack by 
white ants. Good subventilation should be secured; that is, a deep 
air space should be left between the ground and wooden flooring. 
If the flooring is to be of concrete, the concrete should be laid on a 
gravel base to prevent dampness. The supports of porches or steps 
should never be laid directly on the ground but should rest on rock 
or concrete. 
In case of the plank platforms in front of suburban railroad sta- 
tions, even if the planking be laid on the proper foundations the 
boards should not be joined closely together, but at least a 41-inch 
space should be left between to allow light and air to penetrate and 
to prevent dampness and infestation by white ants. Often these 
1 The use of concrete on the farm. U.S. Dept. Agr. Farmers’ Bul. 461, 23 p., 10 fig. 1915. 
Concrete construction on the live-stock farm. U.S. Dept. Agr. Farmers’ Bul. 481, 32 p., 24 fig. 1915. 
2 Page, L. W. Oil-mixed Portland cement concrete. U.S. Dept. Agr. Bul. 230, 26 p.,6pl.,5 fig. . 1916. 
