XV, i 
Oshima: Formosan Termites 
343 
Fig. 2. Detail of termite-proof construction ; a continuous layer of ce- 
ment at ground level. 
however, that cement concrete is quite safe against the attack 
of the termite, while lime concrete is not. Not only is the 
first method of attack almost impossible, but the second as well, 
for the drains are so constructed that they catch rain water from 
the eaves and thus prevent the intrusion of the pest. In the 
dry season the termite very often crosses the drains; but its 
covered tunnels can be found at once and it is readily driven 
out, because the outer parts of the concrete layer extend beyond 
the external wall and are used as sidewalks. 
The aim of constructing a continuous layer of concrete above 
the ground level is to prevent absolutely the entering of the 
termite by means of an impermeable barrier. Great care should 
be taken, therefore, to keep the whole layer perfectly compact, 
and to avoid the occurrence of cracks and pores. To do so, 
the entire layer must be spread at the same time, in a continuous, 
even plane. 
One of the practical difficulties of constructing a continuous 
concrete layer is that it stops construction of all other parts 
of the building until the concrete is entirely set. To get rid 
of this difficulty, the methods shown in figs. 3 and 4 are very 
often adopted. The concrete layer is divided into two or three 
Fig. 3. Detail of termite-proof construction ; a layer of cement 
at ground level laid in two parts. 
