the Malay Peninsula owes to Mr. RUSSELL and the Federated En- 
gineering Company for the time, trouble and money that was spent 
in making a machine for exhibition — the first of its kind ever seen 
in this part of the world — must not be overlooked. 
Without it words would have been weak, I fear futile, seeing is 
and was believing, 
APPENDIX /. 
The Rubber-Washing Machine. 
This machine consists essentially of two steel rollers which 
revolve on horizontal axes parallel to one another, the distance 
between the surfaces of the two rollers can be adjusted and varies 
from | inch to practical contact. 
The rollers revolve at different speeds and are driven by power 
transmitted from belt and pulley, through gear wheels to the rollers 
themselves. 
The axes of the two rollers may be on the same horizontal plane, 
more usually one is slightly above the other, a stream of water 
flows over the surfaces of the rollers all the time they are in use. 
When the machine is used, freshly coagulated lumps of rubber 
are put between the rollers, which are separated about | inch. The 
rubber is passed through several times, the rollers being gradually 
approximated to each other — -and the rubber becomes compacted 
and to some degree hardened. At the same time the effect of the 
differential rate of movement of the two roller surfaces is to subject 
the rubber to a shearing stress, which stretches and tears it to 
pieces, and it is here that the peculiar property of rubber is clearly 
seen. The elastic stretching and rebound, kick out any gross 
mechanical impurity that may be present, and when the machine 
is used on scrap rubber there is a perfect shower of dirt, pieces of 
bark and wood thrown out from the front of the machine. Freshly 
cut or torn surfaces of rubber re-unite on contact and pressure, 
for this reason the fragments into which the rubber is torn by the 
machine re-unite and emerge as a continuous sheet. At th<* same 
time the stream of water thoroughly washes out any impurity 
soluble in water that may be left in the rubber. The final product 
is a coherent but granular sheet of rubber, the thickness of which 
can be regulated by the distance left between the rollers. The 
function of the machine is thus threefold : — 
Firstly it ejects mechanically any solid impurity ; 
Secondly it breaks up the rubber and subjects all portions of 
the rubber to the washing effect of flowing water; 
Thirdly it produces granular thin sheet of uniform thickness 
which is clean and which can easily and rapidly be dried. 
